RocketCat sez

Listen up, space cadets! Here's the deal:

Spaceship and spacestation cabins have air at full pressure. If you use air at low pressure the blasted atmo is pure oxy, which is like swimming in a pool of gasoline while idly flicking your Zippo.

Soft space suits are only terribly encumbering, like wearing three snow suits at once. This is their advantage. Disadvantages include the fact they can be punctured by a pair of kindergarten safety scissors, causing certain death. Oh, and they can only use low pressure because high pressure will make the suit spread-eagle you like somebody strapped to a Saint Andrew's Cross who forget the safeword. Low pressure means you have to do a few hours of pre-breathing or the suit will kill you with The Bends. Which is a problem if an emergency strikes and you don't have a few hours.

Hard shell space suits advantages are: they can use high pressure atmo so you can't get the bends, you don't need to pre-breathe, and you'd need a freaking handgun to puncture it. Disadvantage is they are monumentally overwhelmingly hideously encumbering like wearing a suit of medieval plate armor made out of solid lead. Soft space suits are only terribly encumbering. (note the "...made of lead", Robert Dougherty points out that standard plate armor made of steel is actually not very encumbering)

Semi-rigid space suits are a cross between soft and hard shell suits. Like all attempts to have it both ways, it means they have the draw-backs of both and the advantages of neither.

Skintight suits have the advantage of being about as encumbering as a wearing leotards, they are quick to put on, and puncturing them just gives you a space-hickey instead of certain death. Disadvantage is they have to use low pressure so The Bends once again raises its ugly head. Also people have a problem getting anybody to take it seriously ("Aw, c'mon, gimmie a break! Who the heck is your suit designer, Earle K. Bergey? Where's the brass brassière?)

A space suit is a protective garment that prevents an astronaut from dying horribly when they step into airless space.

Also known as atmosphere suit, vac suit, pressure suit, space armor, environment(al) suit, e-suit, EVA suit.

SF author Sir Arthur C. Clarke said "We seldom stop to think that we are still creatures of the sea, able to leave it only because, from birth to death, we wear the water-filled space suits of our skins." SF author Ken MacLeod said that the specification of a human being is "a space suit for a fish."

Current NASA suits look like baggy inflated coveralls with a large back pack and a spherical fishbowl over the head. Often in old illustrations there are accordion bellows at the joints.

NASA astronaut always put on a transdermal dimenhydrinate anti-nausea patch when suiting up in a space suit, in case of drop sickness. The chances of that are slight, but suffocating inside a helmet full of vomit is a nasty way to die.

Most space suits are Full (Body) Pressure-suits: they offer pressurization of the entire body in space for extended periods. Partial (Body) Pressure-suits only pressurize certain parts of the body for a limited time. They are only used as a precaution, worn inside the habitat module during times when there is danger of it springing a leak (such as during lift-off).

Full-(Body) Pressure-suits can be either Low-Pressure (pure oxygen at 32.4 kPa) or High-Pressure (breathing mix at 101.3 kPa, normal Terran atmospheric pressure).

All NASA spacecraft and space station habitat modules are High-Pressure. At least the ones designed after the Apollo 1 tragedy claimed the lives of three astronauts. Ever since NASA has avoided using pure oxygen atmosphere wherever possible, which means using high-pressure.

The problem is if you go from a high-pressure environment (like a habitat module) into a low-pressure environment (like a low-pressure space suit) you run the risk of the bends. To avoid this the astronaut must do pre-breathing for a couple of hours. If you go from a high-pressure habitat module into a high-pressure space suit the bends does not happen. This is why high-pressure space suits are called "zero-prebreathe" suits.

I suppose some space-faring nation could use low-pressure pure-oxygen habitat modules to avoid pre-breathing with low-pressure space suits, but that would be insanely dangerous. It would be the outer-space equivalent of those stubborn elderly hospital patients who insist on smoking cigarettes while wearing oxygen tanks. A disaster just waiting to happen.

NASA tolerates low-pressure pure-oxygen pressurization in their soft space suits because they have no choice. There is not a lot of research, but NASA seems to think that if an astronaut in such a suit got punctured by a micro-meteor and it caught fire, the main hazard is a fire enlarging the diameter of the breach, not an astronaut-shaped ball of flame.

For what it is worth, the "Apollo Operations Handbook Extravehicular Mobility Unit", Revision 5, Table 2-I quotes the maximum leak rate of 180 cubic centimeters per minute at 25.5 kPa.

Suits can be Soft, Hard-shell, Semi-Rigid/Hybrid or Skintight.

Soft suits have flexible exteriors. This means they cannot be pressurized to the same level as the inside of the habitat module or the space suited person will be forced into a posture like a star-fish and helplessly be unable to bend any joints. Lower pressure means the suit uses pure oxygen unlike the habitat module. And pure oxygen means the astronaut has to do hours pre-breathing before wearing the suit or they will be stricken by The Bends.

Soft suits also take forever to put on, they fight your every movement (making EVA work very fatiguing), and if you tear the suit skin you will die horribly in about 90 seconds. When I say "fight your every movement" I mean "raise the energy expenditure to do a task by about 400%".

Currently most of NASA's space suits are soft suits.

Hard-shell suits have rigid exteriors. The advantage is they can be fully pressurized so no pre-breathing is required. They are also much more tear and puncture resistant than soft suits.

The drawback of hard-shell suits is that they make the "forever to put on" and "fight your every movement" problems much worse.

As far as I know there are no hard-shell suits in active use, they are all experimental.

Semi-rigid or Hybrid suits are a cross between soft and hard-shell. For instance, NASA's EMU has a hard-shell upper torso and soft fabric limbs. Current NASA semi-rigid suits are low pressure, but they are working on a high-pressure model.

Skintight suits are a radical concept that is so crazy it just might work. They make the astronaut's skin into the spacesuit, using high-tech spandex to supply pressure instead of using atmosphere. They can be quickly put on, fight your every movement only to the point of a +20% increase in energy, and if the suit is torn the astronaut only gets a bruise instead of certain death. The suits are also much inexpensive than a soft or hard-shell suit. The major draw-back is they require low pressure breathing mix (or the wearer cannot exhale), so astronauts have to pre-breath or face the Bends.

"Planetary suits" are used when there is an atmosphere, but it isn't breathable. They have a slightly different design from space suits.


Beta cloth is a type of fireproof silica fiber cloth used in the manufacture of Apollo/Skylab A7L space suits, the Apollo Thermal Micrometeoroid Garment, the McDivitt Purse, and in other specialized applications.

Beta cloth consists of fine woven silica fiber, similar to fiberglass. The resulting fabric does not burn, and melts only at temperatures exceeding 650 °C (1,200 °F). To reduce its tendency to crease or tear when manipulated, and to increase durability, the fibers are coated with Teflon.


The tight weave of Beta cloth makes it more resistant to atomic oxygen exposure. Its ability to resist atomic oxygen exposure means it is commonly used as the outer-most layer of multi-layer insulation for space; it was used on the Space Shuttle and the International Space Station.

It was incorporated into NASA space suits after the deadly 1967 Apollo 1 launch pad fire, in which the astronauts' nylon suits burned through. After the fire, NASA demanded any potentially flammable materials be removed from both the spacecraft and space suits. Beta cloth was developed by a Manned Spacecraft Center team led by Frederick S. Dawn and including Matthew I. Radnofsky working with the Owens-Corning and DuPont companies.

Where additional wear resistance was needed, external patches of Chromel-R metallic cloth were used.

Beta cloth was used as the material for the Skylab shower enclosure.

The interior of the Space Shuttle payload bay was almost completely covered with Beta cloth. This protected it while it was opened for weeks at a time in space.

Beta cloth is used on the Curiosity rover.

From the Wikipedia entry for BETA CLOTH

(ed note: The crew of the Skylark try to use their newly invented space suits, which have never been actually tested in the field)

After an interminable silence, DuQuesne drew himself out of his seat. He took a long inhalation, deposited the butt of his cigarette carefully in his ash tray, and made his way to his room (oh, come now! Smoking in a spaceship? RocketCat would extinguish the cigarette by yanking it out of your mouth then inserting it into one of your body's orifices...). He returned with three heavy fur suits provided with air helmets, two of which he handed to the girls, who were huddled in a seat with their arms around each other. These suits were the armor designed by Crane for use in exploring the vacuum and the intense cold of dead worlds. Air-tight, braced with fine steel netting, and supplied with air at normal pressure from small tanks by automatic valves, they made their wearers independent of surrounding conditions of pressure and temperature.

Hastily returning to the main compartment, he briefly informed the girls as to what had happened. All three donned the suits and stationed themselves at the upper opening. Rapidly, but with unerring precision, the two ships were brought into place and held together by the attractor. As the doors were opened, there was a screaming hiss as the air of the vessels escaped through the narrow crack between them. The passengers saw the moisture in the air turn into snow, and saw the air itself first liquefy and then freeze into a solid coating upon the metal around the orifices at the touch of the frightful cold outside—the absolute zero of interstellar space, about four hundred sixty degrees below zero in the every-day scale of temperature. The moisture of their breath condensed upon the inside of the double glasses of their helmets, rendering sight useless.

'Blast!' Seaton's voice came tinnily over the helmet radios. 'I can't see a foot. Can you, DuQuesne?'

'No, and these joints don't move more than a couple of inches.'

'These suits need a lot more work. We'll have to go by feel. Pass 'em along.'

DuQuesne grabbed the girl nearest him and shoved her toward the spot where Seaton would have to be.

From THE SKYLARK OF SPACE by E. E. "Doc" Smith (1928)

(ed note: this was written in 1958 but is remarkably accurate. NASA suits are not quite like this, but the described suit will work. In any event, it will give you an idea what it feels like to wear a space suit. The illustration above by Stephen Hickman follows the description quite closely, and also includes accurate details not mentioned in the text.

The name of the novel is a pun based on a then popular TV show Have Gun – Will Travel. I personally remember watching it, but it probably went off the air before your grandfather was born.)

      It was a space suit.
     Not much, as space suits go these days. It was an obsolete model that Skyway Soap had bought as surplus material—the tenth-to-hundredth prizes were all space suits. But it was a real one, made by Goodyear, with air conditioning by York and auxiliary equipment by General Electric. Its instruction manual and maintenance-and-service log were with it and it had racked up more than eight hundred hours in rigging the second satellite station.
     When we came back, a reporter from the Clarion was there with a photographer—the paper had known I was a winner before I did, which didn’t seem right.
     They wanted pictures and I didn’t mind.
     I had an awful time getting into it—dressing in an upper berth is a cinch by comparison. The photographer said, “Just a minute, kid. I’ve seen ‘em do it at Wright Field. Mind some advice?”
     “Uh? No. I mean, yes, tell me.”
     “You slide in like an (Inuit) climbing into a kayak. Then wiggle your right arm in—“
     It was fairly easy that way, opening front gaskets wide and sitting down in it, though I almost dislocated a shoulder. There were straps to adjust for size but we didn’t bother; he stuffed me into it, zippered the gaskets, helped me to my feet and shut the helmet.
     It didn’t have air bottles and I had to live on the air inside while he got three shots. By then I knew that the suit had seen service; it smelled like dirty socks. I was glad to get the helmet off.

     Just the same, it made me feel good to wear it. Like a spacer.

     But I didn’t get tired of it; a space suit is a marvelous piece of machinery—a little space station with everything miniaturized. Mine was a chrome-plated helmet and shoulder yoke which merged into a body of silicone, asbestos, and glass-fibre cloth (you cannot use rubber. The rubber's oil will boil away in vacuum and the remainder will shatter like glass). This hide was stiff except at the joints. They were the same rugged material but were “constant volume” — when you bent a knee a bellows arrangement (looks like an accordion) increased the volume over the knee cap as much as the space back of the knee was squeezed. Without this a man wouldn’t be able to move; the pressure inside, which can add up to several tons, would hold him rigid as a statue. These volume compensators were covered with dural armor; even the finger joints had little dural plates over the knuckles.
     It had a heavy glass-fibre belt with clips for tools, and there were the straps to adjust for height and weight. There was a back pack, now empty, for air bottles, and zippered pockets inside and out, for batteries and such.
     The helmet swung back, taking a bib out of the yoke with it, and the front opened with two gasketed zippers; this left a door you could wiggle into. With helmet clamped and zippers closed it was impossible to open the suit with pressure inside.
     Switches were mounted on the shoulder yoke and on the helmet; the helmet was monstrous. It contained a drinking tank, pill dispensers six on each side, a chin plate on the right to switch radio from “receive” to “send,” another on the left to increase or decrease flow of air, an automatic polarizer for the face lens, microphone and earphones, space for radio circuits in a bulge back of the head, and an instrument board arched over the head. The instrument dials read backwards because they were reflected in an inside mirror in front of the wearer’s forehead at an effective fourteen inches from the eyes.
     Above the lens or window there were twin headlights. On top were two antennas, a spike for broadcast and a horn that squirted microwaves like a gun—you aimed it by facing the receiving station. The horn antenna was armored except for its open end.
     This sounds as crowded as a lady’s purse but everything was beautifully compact; your head didn’t touch anything when you looked out the lens. But you could tip your head back and see reflected instruments, or tilt it down and turn it to work chin controls, or simply turn your neck for water nipple or pills. In all remaining space sponge-rubber padding kept you from banging your head no matter what. My suit was like a fine car, its helmet like a Swiss watch. But its air bottles were missing; so was radio gear except for built-in antennas; radar beacon and emergency radar target were gone, pockets inside and out were empty, and there were no tools on the belt. The manual told what it ought to have—it was like a stripped car.

     I decided I just had to make it work right.

     First I swabbed it out with Clorox to kill the locker-room odor. Then I got to work on the air system.
     It’s a good thing they included that manual; most of what I thought I knew about space suits was wrong.
     A man uses around three pounds of oxygen a day—pounds mass, not pounds per square inch. You’d think a man could carry oxygen for a month, especially out in space where mass has no weight, or on the Moon where three pounds weigh only half a pound. Well, that’s okay for space stations or ships or frogmen; they run air through soda lime to take out carbon dioxide, and breathe it again. But not space suits.
     Even today people talk about “the bitter cold of outer space”—but space is vacuum and if vacuum were cold, how could a Thermos jug keep hot coffee hot? Vacuum is nothing—it has no temperature, it just insulates.
     Three-fourths of your food turns into heat—a lot of heat, enough each day to melt fifty pounds of ice and more. Sounds preposterous, doesn’t it? But when you have a roaring fire in the furnace, you are cooling your body; even in the winter you keep a room about thirty degrees cooler than your body. When you turn up a furnace’s thermostat, you are picking a more comfortable rate for cooling. Your body makes so much heat you have to get rid of it, exactly as you have to cool a car’s engine.
     Of course, if you do it too fast, say in a sub-zero wind, you can freeze—but the usual problem in a space suit is to keep from being boiled like a lobster. You’ve got vacuum all around you and it’s hard to get rid of heat.
     Some radiates away but not enough, and if you are in sunlight, you pick up still more—this is why space ships are polished like mirrors.

     So what can you do?

     Well, you can’t carry fifty-pound blocks of ice. You get rid of heat the way you do on Earth, by convection and evaporation—you keep air moving over you to evaporate sweat and cool you off. Oh, they’ll learn to build space suits that recycle like a space ship but today the practical way is to let used air escape from the suit, flushing away sweat and carbon dioxide and excess heat—while wasting most of the oxygen.
     There are other problems. The fifteen pounds per square inch around you includes three pounds of oxygen pressure. Your lungs can get along on less than half that, but only an Indian from the high Andes is likely to he comfortable on less than two pounds oxygen pressure. Nine-tenths of a pound is the limit. Any less than nine-tenths of a pound won’t force oxygen into blood—this is about the pressure at the top of Mount Everest.
     Most people suffer from hypoxia (oxygen shortage) long before this, so better use two p.s.i. of oxygen. Mix an inert gas with it, because pure oxygen can cause a sore throat or make you drunk or even cause terrible cramps. Don’t use nitrogen (which you’ve breathed all your life) because it will bubble in your blood if pressure drops and cripple you with “bends.” Use helium which doesn’t. It gives you a squeaky voice, but who cares?
     You can die from oxygen shortage, be poisoned by too much oxygen, be crippled by nitrogen, drown in or be acid-poisoned by carbon dioxide, or dehydrate and run a killing fever. When I finished reading that manual I didn’t see how anybody could stay alive anywhere, much less in a space suit.

     But a space suit was in front of me that had protected a man for hundreds of hours in empty space.

     Here is how you beat those dangers. Carry steel bottles on your back; they hold “air” (oxygen and helium) at a hundred and fifty atmospheres, over 2000 pounds per square inch; you draw from them through a reduction valve down to 150 p.s.i. and through still another reduction valve, a “demand” type which keeps pressure in your helmet at three to five pounds per square inch—two pounds of it oxygen. Put a silicone-rubber collar around your neck and put tiny holes in it, so that the pressure in the body of your suit is less, the air movement still faster; then evaporation and cooling will be increased while the effort of bending is decreased. Add exhaust valves, one at each wrist and ankle—these have to pass water as well as gas because you may be ankle deep in sweat.
     The bottles are big and clumsy, weighing around sixty pounds apiece, and each holds only about five mass pounds of air even at that enormous pressure; instead of a month’s supply you will have only a few hours—my suit was rated at eight hours for the bottles it used to have. But you will be okay for those hours—if everything works right. You can stretch time, for you don’t die from overheating very fast and can stand too much carbon dioxide even longer—but let your oxygen run out and you die in about seven minutes. Which gets us back where we started—it takes oxygen to stay alive.
     To make darn sure that you’re getting enough (your nose can’t tell) you clip a little photoelectric cell to your ear and let it see the color of your blood; the redness of the blood measures the oxygen it carries. Hook this to a galvanometer. If its needle gets into the danger zone, start saying your prayers.

     I went to Springfield on my day off, taking the suit’s hose fittings, and shopped. I picked up, second hand, two thirty-inch steel bottles from a welding shop—and got myself disliked by insisting on a pressure test. I took them home on the bus, stopped at Pring’s Garage and arranged to buy air at fifty atmospheres. Higher pressures, or oxygen or helium, I could get from the Springfield airport, but I didn’t need them yet.
     When I got home I closed the suit, empty, and pumped it with a bicycle pump to two atmospheres absolute, or one relative, which gave me a test load of almost four to one compared with space conditions. Then I tackled the bottles. They needed to be mirror bright, since you can’t afford to let them pick up heat from the Sun. I stripped and scraped and wire-brushed, and buffed and polished, preparatory to nickel-plating.

     Next morning, Oscar the Mechanical Man was limp as a pair of long johns.

     Getting that old suit not just airtight but helium-tight was the worst headache. Air isn’t bad but the helium molecule is so small and agile that it migrates right through ordinary rubber—and I wanted this job to be right, not just good enough to perform at home but okay for space. The gaskets were shot and there were slow leaks almost impossible to find.
     I had to get new silicone-rubber gaskets and patching compound and tissue from Goodyear; small-town hardware stores don’t handle such things. I wrote a letter explaining what I wanted and why—and they didn’t even charge me. They sent me some mimeographed sheets elaborating on the manual.

     It still wasn’t easy. But there came a day when I pumped Oscar full of pure helium at two atmospheres absolute.
     A week later he was still tight as a six-ply tire.

     That day I wore Oscar as a self-contained environment. I had already worn him many hours without the helmet, working around the shop, handling tools while hampered by his gauntlets, getting height and size adjustments right. It was like breaking in new ice skates and after a while I was hardly aware I had it on—once I came to supper in it. Dad said nothing and Mother has the social restraint of an ambassador; I discovered my mistake when I picked up my napkin.
     Now I wasted helium to the air, mounted bottles charged with air, and suited them. Then I clamped the helmet and dogged the safety catches.

     Air sighed softly into the helmet, its flow through the demand valve regulated by the rise and fall of my chest—I could reset it to speed up or slow down by the chin control. I did so, watching the gauge in the mirror and letting it mount until I had twenty pounds absolute inside. That gave me five pounds more than the pressure around me, which was as near as I could come to space conditions without being in space.
     I could feel the suit swell and the joints no longer felt loose and easy. I balanced the cycle at five pounds differential and tried to move—And almost fell over. I had to grab the workbench.
     Suited up, with bottles on my back, I weighed more than twice what I do stripped. Besides that, although the joints were constant-volume, the suit didn’t work as freely under pressure. Dress yourself in heavy fishing waders, put on an overcoat and boxing gloves and a bucket over your head, then have somebody strap two sacks of cement across your shoulders and you will know what a space suit feels like under one gravity.
     But ten minutes later I was handling myself fairly well and in half an hour I felt as if I had worn one all my life. The distributed weight wasn’t too great (and I knew it wouldn’t amount to much on the Moon). The joints were just a case of getting used to more effort. I had had more trouble learning to swim.

     It was a blistering day: I went outside and looked at the Sun. The polarizer cut the glare and I was able to look at it. I looked away; polarizing eased off and I could see around me.
     I stayed cool. The air, cooled by semi-adiabatic expansion (it said in the manual), cooled my head and flowed on through the suit, washing away body heat and used air through the exhaust valves. The manual said that heating elements rarely cut in, since the usual problem was to get rid of heat; I decided to get dry ice and force a test of thermostat and heater.
     I tried everything I could think of. A creek runs back of our place and beyond is a pasture. I sloshed through the stream, lost my footing and fell —the worst trouble was that I could never see where I was putting my feet. Once I was down I lay there a while, half floating but mostly covered. I didn’t get wet, I didn’t get hot, I didn’t get cold, and my breathing was as easy as ever even though water shimmered over my helmet.
     I scrambled heavily up the bank and fell again, striking my helmet against a rock. No damage, Oscar was built to take it. I pulled my knees under me, got up, and crossed the pasture, stumbling on rough ground but not falling. There was a haystack there and I dug into it until I was buried.

     Cool fresh air … no trouble, no sweat.

     After three hours I took it off. The suit had relief arrangements like any pilot’s outfit (a tube you can pee into, leading to a bag that catches the urine) but I hadn’t rigged it yet, so I had come out before my air was gone. When I hung it in the rack I had built, I patted the shoulder yoke. “Oscar, you’re all right,” I told it. “You and I are partners. We’re going places.” I would have sneered at five thousand dollars for Oscar.

     While Oscar was taking his pressure tests I worked on his electrical and electronic gear. I didn’t bother with a radar target or beacon; the first is childishly simple, the second is fiendishly expensive. But I did want radio for the space-operations band of the spectrum—the antennas suited only those wavelengths. I could have built an ordinary walkie-talkie and hung it outside—but I would have been kidding myself with a wrong frequency and gear that might not stand vacuum. Changes in pressure and temperature and humidity do funny things to electronic circuits; that is why the radio was housed inside the helmet.
     The manual gave circuit diagrams, so I got busy. The audio and modulating circuits were no problem, just battery-operated transistor circuitry which I could make plenty small enough. But the microwave part—It was a two-headed calf, each with transmitter and receiver—one centimeter wavelength for the horn and three octaves lower at eight centimeters for the spike in a harmonic relationship, one crystal controlling both. This gave more signal on broadcast and better aiming when squirting out the horn and also meant that only part of the rig had to be switched in changing antennas. The output of a variable-frequency oscillator was added to the crystal frequency in tuning the receiver. The circuitry was simple—on paper.
     But microwave circuitry is never easy; it takes precision machining and a slip of a tool can foul up the impedance and ruin a mathematically calculated resonance.
     Well, I tried. Synthetic precision crystals are cheap from surplus houses and some transistors and other components I could vandalize from my own gear. And I made it work, after the fussiest pray-and-try-again I have ever done. But the consarned thing simply would not fit into the helmet.

     Call it a moral victory—I’ve never done better work.

     I finally bought one, precision made and embedded in plastic, from the same firm that sold me the crystal. Like the suit it was made for, it was obsolete and I paid a price so low that I merely screamed. By then I would have mortgaged my soul—I wanted that suit to work.
     The only thing that complicated the rest of the electrical gear was that everything had to be either “fail-safe” or “no-fail”; a man in a space suit can’t pull into the next garage if something goes wrong—the stuff has to keep on working or he becomes a vital statistic. That was why the helmet had twin headlights; the second cut in if the first failed—even the peanut lights (old school incandescent light bulbs that used to be used to illuminate automobile license plates) for the dials over my head were twins. I didn’t take short cuts; every duplicate circuit I kept duplicate and tested to make sure that automatic changeover always worked.
     Mr. Charton (local pharmacist) insisted on filling the manual's list on those items a drugstore stocks — maltose and dextrose and amino tablets, vitamins, dexedrine (yikes, back in 1958 the drugstore would give an 18 year old boy amphetamines!), dramamine, aspirin, antibiotics, antihistamines, codeine, almost any pill a man can take to help him past a hump that might kill him. He got Doc Kennedy to write prescriptions so that I could stock Oscar without breaking laws.

(ed note: When Kip got his suit, he purchased from the local druggest the standard medications a Goodyear space suit carried inside the helmet. Of course no sane pharmacist nowadays would even dream of selling amphetamines to a high-school kid, space-suit or not. In 1958 dexedrine was called "pep-pills." Nowadays it is called a Schedule II controlled substance)

     When I got through Oscar was in as good shape as he had ever been in Satellite Two. It had been more fun than the time I helped Jake Bixby turn his heap into a hotrod.

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)

Partial-Pressure Suits

To recap: Partial Pressure suits only pressurize certain parts of the body for a limited time. They are only used as a precaution, worn inside the habitat module during times when there is danger of it springing a leak, such as during lift-off or if an enemy spacecraft is shooting at you. Partial pressure suits are a trade-off: they only protect you for a short time but in exchange they do not encumber you anywhere near as much as a total pressure suit.

The NASA version is the Launch Entry Suit aka "pumpkin suit." It has ten minutes worth of life support internal to the suit, and can be hooked up to the vehicles life support system for longer duration.

The image above from First Men to the Moon is a partial pressure suit based on an old school Air Force high-altitude suit. If the pressure drops, the pressure regulating tubes along the suit's seams inflate to put the suit under tension. The wearer will then put on the oxygen mask attached to the small tank strapped to their leg.

Soft Suits

To recap, Soft Suits:

  • Must have lower pressure than the habitat module or the wearer turns into a starfish and cannot bend their limbs. This means the wearer needs an hour of pre-breathing or they will suffer the Bends.
  • In case of emergency, when there is no time for pre-breathing, NASA helpfully directs the astronauts to gulp aspirin, so they can work in spite of the agonizing pain
  • The breathing mix will be close to pure oxygen, with a higher fire risk.
  • Suit encumbrance increases the energy cost to do various tasks by +400%, with a corresponding increase in wearer fatigue.
  • If the soft skin of the suit is torn or punctured, the wearer will die in about 90 seconds.
  • They take forever to put on

For a list of the parameters for a NASA spec space suit, go here.

The only thing that allows an astronaut to bend their limbs at all is the magic of constant volume joints. These are why most pictures of space suits look like the Michelin Man, with joints that look like accordions.

Dan chuckled, then sobered. "Like that, eh? Okay, you won't get any favors. But you'll still stay here today. Look, Jim, when I first came up, there was a guy named Joe with me. The first day he spotted some cargo drifting off and leaped for it. Put out a hand to grab it—and, naturally, when his arm moved one way his body moved the other. His suit hit a sharp edge of metal. A man dies fast out here when the air runs out of his suit, and it's not a pretty thing to see. You stay inside."

Jim practiced dutifully, gaining some proficiency as he did. He had to learn by experience that the twitch of a foot at the wrong moment could throw him off balance.

From STEP TO THE STARS by Lester Del Rey (1954)


I have mentioned how science fiction authors can look to the past to find solutions for the future. Well, occasionally this works in the real world as well.

Back in the early 1960s NASA was gearing up for the Apollo program. And they were frankly having a problem designing the space suits.

The space suits used by the Mercury program astronauts were quick-and-dirty knock-offs, basically modified 1950s US Navy jet pilot pressurized flight suits. The Mercury suits were designed for suborbital flights, not moon missions. They sewed simple fabric break lines into the elbows and knees of the Navy nylon suits. Predictably the suits were crap. Astronauts found it almost impossible to blend their legs and arms. It was barely usable for Mercury, but it ain't gonna work for Apollo. A moon space suit has to be rigid and durable (because the moon is a sharp and pointy puncture-prone place and space suits are like big balloons) yet also flexible enough so the astronauts can move and explore the moon.

So in 1962, an outfit called Garrett AiResearch was contracted to help design the moon suits. It was real hard. Nothing like trying to engineer two mutually exclusive properties into a single object to generate lots of head-shaped dents in the wall. After a lot of skull-sweat the company suddenly had the thought that this might be an already solved problem. Was not this the exact same design challenge faced when making medieval suits of armor?

Garrett AiResearch reached out to the New York Metropolitan Museum, who referred them to the Tower of London.

Now most middle-ages suits of armor were meant to be used on horseback. Those had huge holes in the armor, particularly around the joints. Unacceptable for a space suit. However foot combat armor tended to have total coverage. That's more like it.

Back in 1500s there was a certain monarch named King Henry the VIII, you may have heard of him. In 1520 (before he developed his huge beer belly) Henry was invited to the Field of Cloth of Gold tournament. Both King Henry VIII of England and King Francis I of France were attending, and both were pulling out all the stops to out-swank each other and impress all of Europe. Kind of like the red carpet of the Oscar awards, except with monarchs instead of divas. Henry had a special suit of foot combat armor made: custom designed to a skin-tight fit, lovingly articulated with incredible flexibility, with the ultimate in precise workmanship and engineering. It was beautiful work. Sadly for Henry a rules change meant the armor was never used in the tourney, and in any event he would soon grow too obese to fit into it.

But the armor was lovingly preserved in the Tower of London. So 450 years later when Garrett AiResearch asked about spacesuit-like suits of armor with fine suppleness, the Tower people knew precisely which suit would be perfect.

The Tower sent Garrett photos and data on the armour, which proved to be invaluable. The engineers marveled at the incredible construction and the way each plate linked smoothly to the next while still allowing flexibility. It was exactly the data they needed. One NASA engineer allegedly said he wished they’d known about Henry’s armour sooner as it would have saved time and money. With this data, the Apollo space suit design came together quickly. Though they did leave out the steel codpiece.

In 1970, to show their graititude, NASA loaned a mock-up of the Apollo suit to the Tower of London so they could take photos of Henry's armor and the spacesuit side-by-side.

Henry's armor currently resides in the Royal Armouries Museum in Leeds in the Tournament gallery, in case you are interested.

Note that such armor would also be a good starting point for military Powered Armor. Though you'll have to "inflate" it a bit so it is not so skin-tight. You need internal space under the armor but over the skin for the motors that give the wearers the strength of Iron Man.


In The Millennial Project Savage suggests that the helmet will have an outer layer of five millimeters of high density lead crystal. Inside will be two layers of dense borosilicate glass sandwiched between two layers of Lexan. The middle layer of Lexan will add strength and prevent shattering, the inner will act as a reserve helmet. The outer surface will be gold anodized to block glare, ultraviolet, and infra-red. There may be a nested set of telescoping curved armor plates that can be deployed for further protection.

NASA helmets are not quite so grandiose.

NASA helmets are spherical domes, which hits the sweet spot between low mass, pressure compensation, and field of view. All current NASA suits have the astronaut's head is held facing forwards, you have to turn your entire body in order to look sideways. Astronauts call this "alligator head".

The helmet has to be comfortable to wear, and help in controlling the humidity inside the helmet (so it doesn't fog up). Another important part is the radio communication unit, since the lack of air in space prevents the sound of your voice from reaching anybody. The old tagline to the first ALIEN movie was "In Space No One Can Hear You Scream". Well, no one can hear Floyd asking somebody to pass him a socket wrench either. NASA suits use "Snoopy caps" to hold the communciation earphones and microphones (in NASA-speak this is called the Communications Carrier Assembly (CCA)).

Other items might include windshield wipers (inside for condensation, outside for dust), a build-in set of binoculars, headlights for shadowed areas, a mirrored sun-visor to prevent sunlight from burning out your retinas, a water drink dispenser, and maybe a gadget that can supply various medications (pain relievers, anti-nausea, stimulants).

As previously mentioned, NASA astronaut always put on a transdermal dimenhydrinate anti-nausea patch when suiting up in a space suit, in case of drop sickness. The chances of that are slight, but suffocating inside a helmet full of vomit is a nasty way to die.


      The helmet swung back, taking a bib out of the yoke with it, and the front opened with two gasketed zippers; this left a door you could wiggle into. With helmet clamped and zippers closed it was impossible to open the suit with pressure inside.
     Switches were mounted on the shoulder yoke and on the helmet; the helmet was monstrous. It contained a drinking tank, pill dispensers six on each side, a chin plate on the right to switch radio from "receive" to "send," another on the left to increase or decrease flow of air, an automatic polarizer for the face lens, microphone and earphones, space for radio circuits in a bulge back of the head, and an instrument board arched over the head. The instrument dials read backwards because they were reflected in an inside mirror in front of the wearer's forehead at an effective fourteen inches from the eyes.
     Above the lens or window there were twin headlights. On top were two antennas, a spike for broadcast and a horn that squirted microwaves like a gun-you aimed it by facing the receiving station. The horn antenna was armored except for its open end.
     This sounds as crowded as a lady's purse but everything was beautifully compact; your head didn't touch anything when you looked out the lens. But you could tip your head back and see reflected instruments, or tilt it down and turn it to work chin controls, or simply turn your neck for water nipple or pills. In all remaining space sponge-rubber padding kept you from banging your head no matter what. My suit was like a fine car, its helmet like a Swiss watch. But its air bottles were missing; so was radio gear except for built-in antennas; radar beacon and emergency radar target were gone, pockets inside and out were empty, and there were no tools on the belt. The manual told what it ought to have — it was like a stripped car.
     The only thing that complicated the rest of the electrical gear was that everything had to be either "fail-safe" or "no-fail"; a man in a space suit can't pull into the next garage if something goes wrong — the stuff has to keep on working or he becomes a vital statistic. That was why the helmet had twin headlights; the second cut in if the first failed — even the peanut lights for the dials over my head were twins. I didn't take short cuts; every duplicate circuit I kept duplicate and tested to make sure that automatic changeover always worked.
     Another thing space suits should have is rearview mirrors. While you are at it, add a window at the chin so that you can see where you step. But of the two, I would take a rearview mirror. You can’t glance behind you; you have to turn your entire body. Every few seconds I wanted to see if they were following us—and I couldn’t spare the effort. All that nightmare trek I kept imagining them on my heels, expecting a wormy hand on my shoulder. I listened for footsteps which couldn’t be heard in vacuum anyhow.

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)

The path towards today’s helmet style grew out of a number of converging interests. Early Spaceflight Initiative helmets required more bulky hardware than modern compact systems, for example, which consumed and obscured much of the rear volume. Later industrial vacuum suits had the disadvantage of holding the wearer’s head in a forward-facing position, due to cushioning and ancillary equipment, restricting the wearer’s field of view. And then, of course, there were the various RFPs from the nascent Imperial Navy, and specifically the requests from the Flight Operations representatives, who were most insistent that while they were willing if reluctant to concede the impracticability of their traditional silk scarves as a vacuum suit accessory, relegating them to the role of dress uniform only, and even to acknowledge the uselessness of their equally traditional aviator goggles, they would not under any circumstances give up their leather-and-fur flight helmets.

(They had, after all, been presented upon graduation of every Pilot Officer since the first foundation of the Imperial Flying Corps. One might as well, in their view, expect a legionary to go into battle without his sword – or, as Military Service slang prefers to put it in either case – ‘stark ruddy naked’.)

And so we come to the modern bubble helmet, a spherical dome of smartglass sandwiched between high-impact sapphiroid. The outermost layer is gold-anodized, to block glare and harmful radiation (while in theory the smartglass could provide this filtration, the gold anodization is fail-safe, functioning even if suit power or data systems are malfunctioning), and designed to intrinsically shed fluids, dust, and electrical charge. The smartglass is capable of acting as an infinitely configurable variable-filter and information display surface, with HUD and augmented reality functions including night-vision and optical zoom. The view provided is unobstructed all around – even beyond the typical 100 degree head rotation – with the exception of two coin-sized spots above the eyeline and to each side where the headlight/camera modules are mounted. A third light/camera module, rear-mounted, provides a projectable rear view. These modules also include miniature trigraphic projectors, enabling the projection of status, communicative, and affective symbols over the wearer’s head.

The helmet is pressurized with the normal canned life support blend of oxygen and inert-mix, to standard ship’s pressure. (Since modern skinsuits incorporate MEMS-based respiration assistance, it is no longer necessary to use high-oxygen breathing mixes.) This is controlled by the systems torc at the base of the helmet, which locks onto the attachment ring/neck dam at the neck of the vacuum suit (itself connected to many fibers running throughout the suit fabric to prevent accidental detachment). Light nanofluid cushioning that surrounds the neck once the helmet is donned provides additional neck protection and stability.

The primary purpose of the systems torc, apart from this connection, is the containment of the suit’s data systems and mesh communications suite. (Its location permits it direct interface with its wearer’s back-neck laser-port, although an auxiliary manual keypad can be connected and mounted on an arm of the suit if desired.) It also contains a miniature high-pressure oxygen tank and rebreather/dehumidifier system as a final hour’s emergency life-support supply. The torc also contains the connectors for the PLSS backpack, including those which permit water, other beverages, food pastes, and pharmaceuticals to be dispensed to the wearer through a deployable pipette, or additionally in the case of pharmaceuticals, through an autoinjector into a neck vein.

Communications can be provided directly by the torc, either via the laser-port interface or via miniaturized microphones and loudspeakers built into the torc surface. Alternately, many wearers prefer the use of a simple headset worn under the helmet, which connects to the torc using local mesh radio.

– A History of Space Hardware, Orbital Education Initiative

From BUBBLE by Alistair Young (2016)


If one has to wear a spacesuit in a vacuum environment for a prolonged period, it would be real nice if you could get a sip of water or a bite of a snack.

The two logical solutions are:

  1. A system inside the suit. Some sort of water bladder with a drinking nipple inside the helmet, and some kind of food dispenser.
  2. Some kind of tiny airlock on the helmet capable of passing external food and drink into the astronaut's mouth without letting all the air out.

After 2000, NASA EVA spacesuits featured a disposable internal drink bag, positioned inside the helmet. It was disposable because the expense of ground refurbishing a reusable drink bag was prohibitive. Science fiction authors make a weak joke by referring to the drink bag as a Gunga Din. A very weak joke.

In NASA-jargon, option 2 is called a "Feedport." Science fiction writer Poul Anderson calls it a "Chowlock" (i.e., a airlock for your chow). In Robert Heinlein's HAVE SPACE SUIT, WILL TRAVEL the high-tech aliens have space helmets made of handwavium force fields. The fields keep the air in, but allows the wearer to drink from a bottle or take a bite of a food bar.

NASA developed feedports for the Apollo space suits for use in emergencies. If the Apollo command module suffered a catastrophic loss of air pressure, any astronaut lucky enough to get into a spacesuit might have to wear the blasted thing for up to 115 hours. Five days is a long time to go without eating or drinking.

The feedport was held close by the internal pressure of the Apollo suit, a low pressure 32.4 kPa. So when the astronaut tries to insert a water dispenser gun into the feedport, they only have to overcome a resistance of 4.7 pounds per square inch. If the suits were high pressure 101.3 kPa, the 14.7 psi resistance would put up far more of a fight.

More mundanely, the feedport had a secondary function: allowing the astronaut to scratch their itching nose.


Hell, we’ve been sleeping nine hours out of the eighteen! Heim glanced at the others. Their suits had become as familiar to him as the seldom seen faces. Jocelyn was already unconscious. Uthg-a-K’thaq seemed to flow bonelessly across the place where he lay. Vadász and Bragdon sat tailor style, but their backs were bent. And every nerve in Heim carried waves of weariness. “All right,” he said.

He hadn’t much appetite, but forced himself to mix a little powder with water and squeeze the mess through his chowlock. When that was done, he stretched himself as well as his backpack allowed.

From THE STAR FOX by Poul Anderson (1965)

Pillsbury developed high-protein Space Food Sticks at the request of NASA, then tried to get people on Earth to eat them.

Once the Apollo astronauts got out to walk and drive around on the Moon, they were, of course, sealed in their spacesuits. The first ones—Neil Armstrong and Buzz Aldrin—were only outside for two-and-a-half hours. But the later moonwalks lasted for seven hours or more, and were physically demanding, and so the astronauts had a snack, mounted ingeniously inside their space helmets, where they could lean over and take a bite.

The delivery system, it would turn out, was more appealing than the snack itself—which dates back to before Apollo started.

As for the space food itself, in 1966, Pillsbury won a government contract to create a “rod-shaped contingency food designed to sustain a flight crew when they must remain sealed within their pressure suits.” Bauman and Pillsbury developed a compressed food bar that was nutrient dense and could deliver the astronauts a burst of energy when they needed it.

Pillsbury developed a commercial version, released in 1969 amid peak Moon fervor and called: Space Food Sticks. The packaging shamelessly promoted Pillsbury’s connection with the space program. “The energy food developed by Pillsbury in support of the U.S. aerospace program” read the large-type copy on the box under the name. Each stick came in a shiny foil wrapper, which gave it a little extra space-age sheen.

Although the space program pioneered the protein bar industry as we know it today, Space Food Sticks in the Apollo era were marketed mostly for dieters or children. The product touted that it had just 44 calories, and the back of the box featured a young blond woman wearing a headband and enjoying one. The TV ads opened and closed with images of a hovering lunar module and are explicitly tailored to space-obsessed kids.

Pillsbury was wise to lean on its connection to the space program, because the bars themselves were unappetizing in appearance (resembling an 8-inch dowel) and were, in effect, a kind of processed candy dressed up as something more. The first two ingredients were sucrose and corn syrup.

The Space Food Sticks were available to the astronauts starting with Apollo 11, and were designed to do exactly what the government asked from Pillsbury: provide contingency food when the astronauts were confined to their pressurized spacesuits. Here’s how Gene Cernan, mission commander of Apollo 17, described the snacking experience:

“We were going to be locked in the suit for maybe nine hours and we had a little water bag that we suspended from the inside rim of the suit … And then we also had one of these high protein or high calorie sticks shaped like a ruler. It was a soft stick and you could chew it. We had it inside a little bag, and it was probably about eight inches long. It, too, was Velcroed just inside the helmet ring and we could put our chin down and pull a little bit out with our teeth, take a bite, chew it for some energy. It was typical candy-tasting stuff. It was nice to be able to suck up a few ounces of water now and then and have something to chew on. That was it; I mean, we had no way of eating or drinking anything other than that. But having some water and a little candy was a real help; it really was.”

There were many other snack options on Earth, though, and Space Food Sticks did not last long on supermarket shelves. The recollections of what Space Food Sticks tasted like vary widely. The most charitable one is that it resembled a Tootsie Roll. The least? “Cat crap in foil pouches” and “gummy hamster food pellets.”


      Time for a break anyway. She sat down on a boulder, fetched a snackpack out of her carryall, and set a timer for fifteen minutes. The airtight quick-seal on the food pack was designed to mate to the matching port in the lower part of her faceplate. It would be important to keep the seal free of grit. She verified the vacuum seal twice before opening the pack into the suit, then pushed the food bar in so she could turn her head and gnaw off pieces. The bar was hard and slightly sweet.

     The nutrition packs are low-residue, but every few days you must still squat for nature. Your life support can’t recycle solid waste, so you wait for the suit to dessicate the waste and then void the crumbly brown powder to vacuum. Your trail is marked by your powdery deposits, scarcely distinguishable from the dark lunar dust.

From A WALK IN THE SUN by Geoffrey A. Landis (1991)

      Mr. Charton insisted on filling the manual's list on those items a drugstore stocks — maltose and dextrose and amino tablets, vitamins, dexedrine (yikes, back in 1958 the drugstore would give an 18 year old boy amphetamines!), dramamine, aspirin, antibiotics, antihistamines, codeine, almost any pill a man can take to help him past a hump that might kill him.

(ed note: When Kip got his suit, he purchased from the local druggest the standard medications a Goodyear space suit carried inside the helmet. Of course no sane pharmacist nowadays would even dream of selling amphetamines to a high-school kid, space-suit or not)

     “Yes,” she said slowly. “I just wish I had salvaged my (chewing) gum, old and tired as it was. My throat’s awful dry.”
     “Drink some water. Not too much.”
     “Kip! It’s not a nice joke.”
     I stared. “Peewee—your suit hasn’t any water?”
     “What? Don’t be silly.”
     My jaw dropped. “But, baby,” I said helplessly, “why didn’t you fill your tank before we left?”
     “What are you talking about? Does your suit have a water tank?”
     I couldn’t answer. Peewee’s suit was for tourists—for those “scenic walks amidst incomparable grandeur on the ancient face of the Moon” that the ads promised. Guided walks, of course, not over a half-hour at a time—they wouldn’t put in a water tank; some tourist might choke, or bite the nipple off and half drown in his helmet, or some silly thing. Besides, it was cheaper.
     I began to worry about other shortcomings that cheap-jack equipment might have—with Peewee’s life depending on it. “I’m sorry,” I said humbly. “Look, I’ll try to figure out some way to get water to you.”
     “I doubt if you can. I can’t die of thirst in the time it’ll take us to get there, so quit worrying. I’m all right. I just wish I had my bubble gum. Ready?”

     While Peewee fumbled at knots, I started to take a drink—then stopped, ashamed of myself. Peewee must be chewing her tongue to work up saliva by now—and I hadn’t been able to think of any way to get water to her. The tank was inside my helmet and there was no way to reach it without making me dead in the process.
     If I ever lived to be an engineer I’d correct that!
     I decided that it was idiotic not to drink because she couldn’t; the lives of all of us might depend on my staying in the best condition I could manage. So I drank and ate three malted milk tablets and a salt tablet, then had another drink. It helped a lot but I hoped Peewee hadn’t noticed. She was busy unwinding clothesline—anyhow it was hard to see into a helmet.
     I should say that I had it fairly easy. I had water, food, pills, dexedrine. The last was enormous help; any time I felt fagged I borrowed energy with a pep-pill. Poor Peewee had nothing but air and courage.

(ed note: In 1958 they called those "pep-pills." Nowadays they call it a Schedule II controlled substance.)

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)


In NASA-speak, the backpack is called the Personal (or Primary or Portable) Life Support System (PLSS). At a minimum, it provides breathing mix, removes carbon dioxide, and regulates the suit's pressure.

Additionally it may remove humidity, odors, and contaminants from the breathing mix; cools the astronaut's body with oxygen or a liquid cooling garment; provides radio communication; displays and/or does telemetry of suit parameters; displays and/or does telementry of astronaut's health; and/or provides propulsion for EVA.

NASA's current design for PLSS is not foolproof, as astronaut Luca Parmitano discovered on July 16, 2013 when he almost died as his helmet filled up with water. The drum holes in the PLSS water separator got clogged, and the PLSS designers had a mistaken understanding of how water acts in microgravity (the designers thought it was impossible for the water to back up into the helmet).

As is usually the case, the reason astronaut Parmitano is alive today is because he did not panic. He had to move to the airlock and re-enter from memory, since he could not see with 1.5 liters of water covering his eyes.


The gloves are especially a problem. Back in the 1950's it was unclear if space suit gloves were even possible. You need to make the various protective layers thin enough to be able to fit between adjacent fingers. And with miniature constant volume cuffs at each finger joint. Some suit designers took a tip from deep sea diving suits and postulated mechanical pincers instead of gloves.

But as we know NASA did manage to design actual space suit gloves. However, they do not work very well. Almost every single NASA astronaut who has performed EVA has complaints about the difficulty of doing any fine work while wearing those gloves.

If you're headed for space, you might rethink that manicure: Astronauts with wider hands are more likely to have their fingernails fall off after working or training in space suit gloves, according to a new study.

In fact, fingernail trauma and other hand injuries—no matter your hand size—are collectively the number one nuisance for spacewalkers, said study co-author Dava Newman, a professor of aeronautics and astronautics at the Massachusetts Institute of Technology.

"The glove in general is just absolutely one of the main engineering challenges," Newman said. "After all, you have almost as many degrees of freedom in your hand as in the rest of your whole body."

The trouble is that the gloves, like the entire space suit, need to simulate the pressure of Earth's atmosphere in the chilly, airless environment of space. The rigid, balloonlike nature of gas-pressurized gloves makes fine motor control a challenge during extravehicular activities (EVAs), aka spacewalks.

A previous study of astronaut injuries sustained during spacewalks had found that about 47 percent of 352 reported symptoms between 2002 and 2004 were hand related. More than half of these hand injuries were due to fingertips and nails making contact with the hard "thimbles" inside the glove fingertips.

In several cases, sustained pressure on the fingertips during EVAs caused intense pain and led to the astronauts' nails detaching from their nailbeds, a condition called fingernail delamination.

While this condition doesn't prevent astronauts from getting their work done, it can become a nuisance if the loose nails gets snagged inside the glove. Also, moisture inside the glove can lead to secondary bacterial or yeast infections in the exposed nailbeds, the study authors say.

If the nail falls off completely, it will eventually grow back, although it might be deformed.

For now, the only solutions are to apply protective dressings, keep nails trimmed short—or do some extreme preventative maintenance.

"I have heard of a couple people who've removed their fingernails in advance of an EVA," Newman said.


Sticky Boots

Many SF novels have magnetized space boots to allow the rocketeers to adhere to the hull, but magnets do not work very well on hulls composed of titanium, aluminum, or magnesium.

If one does have a ferromagnetic hull, it might be best to have magnets just in the boot heels but not the toes, to facilitate walking. The idea is that if a boot is attached to the hull, you can release it by pushing down with your toes and lifing your heel, using a natural walking motion to detach the magnetic heel. Then the boot moves forward, approaching the hull heel-first. This allows the magnet in the heel to attach.

This topic is gone into in more depth here.

Hard-Shell Suits

To recap, Hard-Shell Suits:

  • Can have the same pressure as the habitat module without the wearer turning into a paralyzed starfish. The Bends are avoided.
  • The breathing mix will be the same or very close to that of the habitat module. No additional fire risk.
  • Suit encumbrance increases the energy cost to do various tasks by many times that of a soft suit, with a incredible increase in wearer fatigue.
  • The hard shell of the suit is very puncture resistant.
  • They take longer to put on than a soft suit.

Hard-shell suits try to fix the tearing problem at the expense of making the first two problems much worse. True, hard suits do solve the depressurization problem, but at such a cost.

The AX-5 hard suit was developed by Hubert Vykukal at NASA Ames Research center in the 1960's. It was based on deep sea diving suit technology created by Phil Nuytten of Nuytco Research. The rotating joints are angled with respect to a limb, with two halves each comprising a thick wedge section and a thin section. When a limb is bent, the joint rotate so that the thin sections come together, allowing the suit limb to bend in a correspoinding fashion. For more details, refer to The Rocket Company.

Semi-Rigid Suits

Semi-rigid Suits are sort of a cross between soft suits and hard-shell suits, typically with the chest or torso hard and the limbs soft.

The ideal design is to have a hard-shell torso allowing the suit to be high-pressure with zero-prebreathing required, coupled with separately pressurized soft limbs to avoid the encumbrance penalty suffered by full-(body) hard-shell pressure-suits.

Which is why NASA's EMU puzzles me, it is a semi-rigid suit that appears to have the disadvantages of both with the advantages of neither. No doubt there were other considerations that I am unaware of.

The company ILC Dover made the Mark III suit as a technology demonstrator in 1992. It actually was a zero prebreathe suit. It is pressurized to 57 kPa, which is close enough to the 101.3 kPa used in NASA habitat modules so that the bends is not an issue. The Mark III had the shell covering the entire torso, not just the chest like the EMU. There is a hard upper torso, a hard lower torso. There are bearings at shoulder, upper arm, hip, waist, and ankles. There are soft fabric joints at elbow, knee, and ankle. I do not know why there are both types of joints at the ankles.

One of its main drawbacks was that the suit could not separate at the waist like other NASA suits, you had to enter the suit from the backpack. As with all hard-shell and semi-rigid suits, it is heavier than a soft suit (59 kilograms).

NASA decided against further development of the Mark III, for whatever reasons.

Skintight Suits

An innovative alternative approach is the Mechanical Counter Pressure (MCP) Suit. Instead of trying to hold your body intact with air pressure, it holds it in with spandex. It sounds crazy but it just might be crazy enough to work.

To recap, Skintight Suits:

  • Must have lower pressure than the habitat module or the wearer cannot empty their lungs. This means the wearer needs an hour of pre-breathing or they will suffer the Bends. Higher pressure also increases the risk of catastrophic failure of the helmet, i.e., shooting off like a champagne cork and killing the wearer.
  • In case of emergency, when there is no time for pre-breathing, NASA helpfully directs the astronauts to gulp aspirin, so they can work in spite of the agonizing pain
  • The breathing mix will be close to pure oxygen, with a higher fire risk.
  • Suit encumbrance only increases the energy cost to do various tasks by +20%, compared to the +400% of soft suits and the astronomical increase of hard-shell suits.
  • Suit punctures result in bruises on the wearer's skin, instead of certain death.
  • Skintight suits are the most inexpensive of all the space suits, about $60,000 US in 2005 dollars.
  • It tends to grab male wearers uncomfortably in the crotch.

The original concept was created by Dr. Paul Webb in 1968. It is currently being developed by Dr. Darva Newman at MIT, under the name "Bio-Suit".

A skin-tight suit of high tech cloth exerts pressure over the rocketeer's body to provide pressure. A bubble helmet with oxygen supply allows one to breathe. Open pores in the suit actually allow the body to be cooled by perspiration. Tears will cause bruising to the skin, but are not as lethal as they are on a conventional suit. The suit can be quickly put on. They do not interfere as much with movement (+20% energy expenditure, compared with +400% for a NASA suit). And you can store them by folding them up and putting them inside the bubble helmet. The back pack is still bulky, though.

They do need some care in design, though. Any concave areas on the body that the suit does not hug will bulge out under internal body pressure until it fills the void (i.e., your armpits will become armhills). Putty or fluid filled bladders will be needed to prevent this. Care must be taken around those nether regions, the small of the back, and in certain locations of the female chest. Male wearers will need a rather sophisticated cup to cover the genitals. Even with the cup, the suit will tend to grab male wearers uncomfortably in the crotch.

And upon entering vacuum, one will have an instant attack of dire flatulence (aka High-altitude flatus expulsion or HAFE). Don't be polite, let it out right away or you may damage your intestines.

There may be a length of tubing added along the seams of the arms, legs, and torso. The suit will be relaxed for easy dressing, then the tubing will be pressurized to put tension on the fabric (This was used in the g-suits worn by early jet pilots). The tubing will automatically pressurize when the helmet is put on and pressured up.

This used to be a standard feature of partial-(body) pressure suits.

A more advanced design uses a strip of "shape metal alloy'. An applied voltage can toggle the metal strip between expanded and contracted.

Unlike other types of space suits, the helmets for skintight suits require something called a "neck dam." This goes around the neck, and tries to keep an air-tight seal. Otherwise the helmet shoots off like a champagne cork and all the air in the helmet will spray out.

I'm sure the neck dam will be the part of the suit that will cause designers the most headaches. I personally would be in favor of straps that go from the neck dam and loop around ones arm around the armpits, but I'm no expert.

In The Millennial Project Savage suggests that light tungsten armor plates be worn over the suit to give some anti-radiation protection (this would only be needed in high radiation areas, like the Van Allen belts).

A minimal version of the skintight suit can be developed for everyday wear inside a spacecraft, i.e., a Partial-(body) Skintight pressure-suit. In cases of emergency air pressure loss, all you'd need is an oxygen mask and earplugs to survive for hours (This was used in Jerry Pournelle's "Tinker". The suit was worn like long johns under a coverall. The coverall is due to the fact that the suit is about as modest as wearing a coat of paint.).

Amusingly, the skintight suit made an appearance in a 1995 novel and anime television series called Rocket Girls. Maybe not so surprisingly, Japanese media in general is noted for its high standards of scientific accuracy. In this case the anime series had JAXA (the Japanese Aerospace eXploration Agency) and real-life Japanese astronaut Naoko Yamazaki as technical advisors.

The fictitious Solomon Space Association is developing the low-mass suits since their anemic one-lung LS-5 rocket can barely lift itself off the launch pad, let alone any payload. In a further desperate attempt to save on mass, they are reduce to using 16 year old girls as astronauts (which is a predictable development for a Japanese anime). They only weigh 38 kilograms, instead of the sixty-odd kilograms of the adult male astronauts. They take up less room in the control cabin as well.

There has even been some serious discussion given to suits more like those worn by the girls on the covers of magazines. We cannot really wear nothing but bathing suits in space, even with a bubble on our heads to supply oxygen to our lungs. (Pressure from the oxygen on the inside of the lungs must be balanced by pressure outside to make breathing possible for any length of time.) For a very short period, the bathing-suit affair might be enough — or even a normal suit of clothes, with an oxygen helmet. This type, though, would be used only as an emergency affair, and might prove very painful in even a few minutes, if not fatal.

Still, it appears that a suit could be designed which would not require that most of it be inflated at all.

The development of the simpler spacesuit almost certainly is not something that will be accomplished on the first trips into space. That type of suit might never work, but it is worth thinking about.

Suppose we keep the plastic helmet and air supply. Let the section around the lungs be the usual inflated tube, puffed out just a trifle beyond the skin, so that air pressure surrounds the lungs. We are still dealing with only 3 pounds pressure of oxygen. Now taper the inflated tube down at the shoulders and waist and change to an elastic fabric that will be skintight over legs, arms and hips. This fabric can be woven or formed so that it will have almost exactly 3 pounds pressure against the skin for every square inch. Yet when we move, there is no change of air pressure at the joints, because the fabric fits against our skin snugly.

We can still cover the material with reflective paint and weave tiny heating wires through it to take care of the temperature. We can even make it just a bit porous, so that perspiration can work through and evaporate into space — as it will do at once. Our bodies naturally cool themselves and maintain an even temperature by controlling the amount of perspiration. The same thing might happen while wearing our spacesuit. If the body became too warm, we would perspire more, and so increase the cooling. Or if we grew too cold, the perspiration would lessen, reducing the cooling. By using some kind of porous underclothing, the perspiration from even the sections inside the pressurized and inflated part of the suit might reach the cooling sections. There would be some loss of oxygen this way, but it could be kept to a level that would not matter for short periods of time.

Perhaps even the part of the suit over the lungs could be devised of similar elastic material, so that there would be oxygen only in the helmet. In that case, instead of huge, bulky suits, we might have something that looked like the tights male ballet dancers wear.

From ROCKETS THROUGH SPACE by Lester Del Rey (1957)

The pressure suit went on like a diver's wet suit, and looked like one only not so thick. It fit very closely; he had to use talcum power to get into it. Gloves dogged onto the ends of the sleeves, and a seal set firmly around his neck. He slipped into the boots, hung the small equipment bag over his shoulder, and reported back to the technicians.

They pulled and pinched, looking for loose spots. They didn't find any in Kevin's, but the next to come up was the girl he'd seen before, and after a moment they handed her a lump of what looked like clay. "Shove that under your breasts," the technician said. "Yeah, right there. Don't leave any gaps."

"But — " She was obviously embarrassed.

"Lady, you're going into vacuum," the man explained. "Your innards will be pressurized to about seven pounds by the air in your helmet. Outside is nothing. Your skin won't hold that. The suit will, but you've got to be flat against the suit, otherwise you'll swell up to fit any empty spaces. It won't do a lot of good for your figure."

"Oh. Thank you," she said. She turned away and used the clay as she'd been told.

From EXILES TO GLORY by Jerry Pournelle (1977)

      "Hullo, laddie. All right in there?"
     Aeneas grabbed for the microphone and pressed the talk switch. "That was one hell of a ride." He fought for control of his voice. "I think I'm all right now."
     "Except that you feel like letting the world's record fart, right?" the voice said. "Go ahead. You'll feel better." (one of the drawbacks of a skintight space suit)
     He tried it. It helped.
     "Hang on there, mate. Be alongside in a minute," the voice said. It took less than that. There were clunks and thuds, and the capsule jarred with some impact. "Righto. You're new in this game, they tell me."
     "Yes, very," Aeneas replied.
     "Right. So we'll start by testing your suit. I've got a bottle attached to the outlet, crack the atmosphere evac valve a half turn, there's a good chap."
     A short moment of panic. The capsule held half an atmosphere. When the capsule was evacuated, only his helmet above the neckseal would contain pressure. The tight garment he wore was supposed to reinforce his own skin so that it would be able to hold the pressure differences, and it had worked in the ground training chamber; but there had been physicians waiting there. Aeneas did as he was told. As the air hissed out, the pressure in his guts returned, but worse.
     "Fart again, lad. How's the breathing?"
     "All right." He carried out the instruction. Again it helped. It was hard work to breathe out, but there didn't seem to be any problems.
     "Good. Open the valve the rest of the way and let's get you out of there." Pumps whirred, and he felt more sensations of internal pressure. The wetsuit was very tight around every part of his body. His heart pounded loudly, and he felt dizzy.
     "Now unstrap and open the hatch."

From HIGH JUSTICE by Jerry Pournelle (1974)

      A blaring horn hammered at his ears and the red emergency light blinked madly. An amplified recording thundered out, replacing the sound of the horn.


     At the moment the horn had been sounded, the emergency locker across the room had crashed open, activated by the same alarms that had sounded the warning.

     ‘Strip and dress,’ Don called out, repeating the drill as he had been taught. At the time it had just been one more thing to learn. He had never thought that he might some day use it.
     His one-piece shipsuit zipped open down the front, and he hopped along on one foot as he tore it off. He kicked off his lightweight sandals at the same time and jumped for the locker.
     The emergency spacesuit was still rocking on the end of the arm that had snapped it out of the storage locker. It was a one-piece suit, almost skintight, cut to an exact fit for him. The helmet dangled forward, away from him, while the entire suit was open down the back.
     ‘Head, right leg, left leg. Right arm, left arm, close,’ he mumbled to himself, repeating the drill.
     Grabbing the handles on the supporting rack, Don bent forward and put his head into the helmet. At the same instant he kicked his right leg into the suit. Automatic valves blew compressed air into the leg so it puffed out like a balloon. As soon as his leg was all the way in, his toes tripped a switch and the air stopped. The suit leg collapsed firmly about his own.
     Then the other leg and his arms, pushing in behind the expanding blast of air. He wriggled his fingers into the glove-like extensions of the arms and, as soon as they were all the way in, he reached out and punched the red knob with the white letters SEAL large upon it.
     The closing device sat on the suit at the base of his spine. It began to suddenly wriggle upwards, like a great insect, pulling the open edges of the suit together and sealing them. When it reached the helmet it dropped off and he was free. And his spacesuit was airtight.

     The entire process, from beginning to end, had taken less than twelve seconds.

     Don’s helmet looked like a round fishbowl with a hole in front of his nose and mouth. A metal cover for this stood open, ready to snap shut if the air pressure fell below five pounds to the square inch. His suit contained only a limited supply of oxygen and this had to be saved until really needed.

From SPACESHIP MEDIC by Harry Harrison (1970)

     On the big screen forward, two men —clad only in T-shirts and tights —are shown in the cramped air lock, struggling with their bright-colored leotard-like space suits, one red and one yellow.
     The material of the suits is lightweight, strong, flexible —but not very elastic. Of necessity, it must be tight fitting; it is a second skin. Two sour-looking crewmen are helping them with the sleeves and leggings.
     A fifth man is cramped against one wall, adjusting the helmets. He snaps a camera onto the left side of one —whatever the man is looking at will be relayed back to the bridge.
     When the men are at last secure in their suits, their helmets are lowered over their heads. The "valets" complete the connections to the mobility and life-support backpack units and check them out. That done, and the units activated, the men snap their face-plates shut, check the helmet seals for security, and lower the appropriate filters into place. They are now bright-colored golems, each with a great dark eye for a face.
     "Radio working?" asks one.
     The other touches his device-studded "chastity belt," a plastic frame around his waist and genitals. "Right."
     A wall panel flashes red —the other crewmen disappear through a hatch which slides impatiently shut after them. A hiss signals that the air is rapidly being drained from the chamber.
     The suits do not puff out; only an occasional bubble of air, trapped under their second skins, reveals that the pressure is quickly decreasing. And then even these too evaporate away. "Bridge, we're ready to go."

From YESTERDAY'S CHILDREN by David Gerrolds (1972)

Latex Space Suit: Yep, these (‘skinsuits’, as opposed to ‘hardsuits’) are in common use – by the civilian spacer, anyway, who has no use for, for example, vacuum-sealed hardshell combat armor – although without the ridiculous semi-Stripperiffic elements (Sheer, you say? Heh. That fabric may contain pores, but it also contains MEMS, computer mesh, wound gel vacuoles…) a lot of media justifies them with, and have been in said use right from the earliest days when the Spaceflight Initiative conducted its feasibility studies for Project Phoenix.

They actually look pretty similar to the prototype of such a spacesuit that Dr. Dava Newman is developing at MIT (illustrated at right), although having smartglass around to provide an infinitely configurable variable filter plus display surface lets them use somethng much more like the classic “clear bubble helmet” *there*. Add a small support/systems backpack, and you’ve got it.

Further information on this general type of spacesuit is, of course, available at Atomic Rocket. In the Imperials’ version, though, I should note further that:

  • Skillful use of smart-fabric (a long way from literal latex) and MEMS for mechanical assistance has got the prebreathing/breathing mix problems down to an irreducible minimum, in modern suits at least.
  • Integrated and self-motile nanofluids have replaced the awkward necessity of stuffing clay into relevant places, at least once you overcome any squeamishness at the way the stuff crawls over you to get there.

Janty Yates, the costume designer for "The Martian," originally looked for inspiration to NASA's prototype Z1 and Z2 spacesuits. She worked with NASA officials and engineers, whom she described as "bend-over-backwards helpful." But in the end, she and her team came up with something new for the main spacesuit in "The Martian".

"We basically had to start from scratch," Yates told "We would've loved to use NASA's designs, but in the end, we just couldn't do it.

"The Martian" director Ridley Scott needed great visuals of Watney's face (as well as the faces of his crewmates) from a variety of angles, and the Z1 and Z2 — which both feature helmets that meld into the shoulder region of the suit — could not meet that requirement, Yates said.

"Ridley needed to see his actors in profile; he needed to see them moving their heads; he needed close-ups on the eyes," said Yates

Aesthetics were also an issue; Scott didn't find the Z-2 spacesuit visually striking enough, Yates said.

Yates worked with concept artists to draw up a variety of basic designs for the suit worn by Watney and his crewmates on the Martian surface, then presented them to Scott for approval. The body-hugging, black-white-and-orange suit showcased in the film emerged by process of elimination. (Interestingly, the movie's suit superficially resembles the Biosuit, a real space garment being developed by researchers at the Massachusetts Institute of Technology.)

So, while NASA didn't come up with the surface suit featured in "The Martian," agency officials did approve the astronaut apparel.

"As we went along, we had to submit the designs for their approval," Yates said. "And they approved along the way, as did the [film's] art department."

"The Martian" features one other spacesuit in addition to the surface suit — a bulky white extravehicular activity (EVA) suit the astronauts wear in space. The film's EVA suit is modeled closely on the one NASA astronauts wear on spacewalks outside the International Space Station, Yates said.

"We kept that very much to NASA style, but we made it a lot more streamlined," she said.


     At least there was no smoke on the bridge. The ventilation system had cleared it. Death by smoke inhalation was almost as bad as death by vacuum. Sandoval fancied she could hear the vacuum on the other side of the hatch scratching to get in and kill them all.
     The Captain and Luch were going over the readings and checking the view on the rest of the deck. Finally the Captain looked up and rubbed his eyes. "Okay. We have a direct hit on this deck which, aside from letting the air out and messing our quarters up did not real harm. But we took that hit right before we went to FTL. Good job on that Sandy. Now we gotta get to the main damage control locker and the space suits there and get them back in here. Then we can see about patching that hole before it lets FTL space in ... that isn't good. And there's ten meters or so of indoor vacuum between us and that locker."
     Sandoval shuddered a bit. FTL entering STL space was never good. As a navigator she knew enough of the theory of FTL to know that. Non-biological entities, jump trauma, flash fever ... the list went on.
     The bridge damage control locker had compressor masks that could be hooked up to a small air tank or air line. No space suits though. In a perfect world they'd be suited up already and at their stations for a hazardous operation. The bridge was too cramped for a locker to hold their suits. It was only designed to keep them alive when things were killing them slowly.
     Using a breathing mask in a vacuum was a good way to kessler your lungs. Absently Sandoval began rooting through the locker, digging through the various odds and ends accumulated over the years. Power bars, lanyards, vacc tape spilled out. What was she looking for? A new hyperdrive to get them to port and a rescue ship?
     "Well I was told this sort of freighter was designed to explode on a direct hit killing us all cleanly," Luch said in mock anger. "I get out of this I'm suing the f*ck*ng shipyard."
     The Captain administered a dopeslap that forced Luchador to adjust the mask he never removed, for no one knew what reason. Sandoval never thought it was polite to ask. "Not the time Luch," the Captain reproved.
     "Sorry sir. A little gallows humor. On the bright side we could hide in the electronics hole and prolong life a few more hours. None of these doors are completely airtight but we could get by."
     "How long till we break out, Sandy?" the Captain asked.
     "At least six days," the small woman answered toying with the materials she'd pulled from the locker. They all knew the air was going to leak out before then. Even with the last refuge of the computer and sensor service crawspace they had maybe a day of air. Air tight doors everywhere was too expensive.
     It wasn't fair. She'd plotted that jump perfectly and in half the time. The ship had ducked missiles and beams like a courier on uppers. They had all performed so well in the face of an invasion and an enemy determined to kill them. It just wasn't good enough. But to die knowing there was a locker full of air tanks not ten meters away was galling.
     Luch grabbed a roll of tape. "We can seal the hatch with this. Buy us a few more hours. We could just say screw it, hit the overrides and open the hatch now. At least it'd be fast. Why do we have so many damn rolls of vacc tape anyway? Your previous quartermaster was a tool, Captain! And this damn ship ... you do everything on the cheap! We're going to die because you didn't spring for some extra spacesuits!"
     The Captain grabbed Luch by the arm and hauled him as far from Sandoval as he could. It wasn't very far. Urgent and harsh whispering followed. The Captain finally ordered the Steward/Mechanic to take a seat and eat a power bar. Sandoval toyed with an old wallet someone had constructed out of tape. Probably an attempt to stave off boredom on a watch during FTL, much like this but without a hole in the hull dooming them all.
     "Hey ... Captain!"
     Adhesive tape was invented in 1845 by Dr. Horace Day. Clear adhesive or tape was made by Richard Drew in 1922 and the Holy Grail: duct tape appeared in 1942. By TL 8 in the year 20-mumblety-rhubarb we have Vacc Tape!
     The salient feature of vacc tape is it works in vacuum. More primitive tapes use adhesives that boil off in vacuum or are destroyed in extreme temperatures. Vacc tape works in extreme temperatures and vacuum ... for a while. By TL 10 synthetic adhesives are able to keep a bond and even strengthen under temperatures extremes to rock hard consistency.
     The other feature of vacc tape is not obvious at first. It changes color in vacuum. A roll of red tape turns a bright blue. Exposure to oxygen turns it red again. Seal a hole with it and air leaking out will turn the tape red making it easy to judge the worth of your damage control. Air bubbles can be spotted and reinforced before they burst. Savvy spacers in an unstable situation or hull will lay strips around the door to the living section. A blue strip around the door indicates vacuum on the other side. Suit up. Some spacers put a strip around the wrist of their space suit as a final check that an airlock that says it is pressurizing is pressurizing.
     Needless to say the stuff also spawns its own craft industry. Spacers make all manner of things, wallets, bags even clothing, slippers and more ...
     "The breathing mask is not ... optimal," Sandoval said. The Captain's voice rattled in her earbud. "Explain?"
     "It's fogging like a sonuvabitch. Also the soft helmet part is inflating. I'm dizzy," she said walking down the corridor. To compound matters, her tape slippers were slippery: a small etymological irony and she was dragging an air line behind her. The journey of ten meters seemed very long.
     She was sure she was starting to feel the bends despite the Captain lowering the bridge's air pressure and switching to a pure oxygen mix.
     It was only logical they use her for a subject. She was the smallest, letting them layer the tape the thickest over her. She was female and needed less oxygen. She thought up the crazy plan.
     She knew her mask was filling with carbon dioxide, or was it monoxide? She always confused the two.  The mask's exhausts were puttied shut. To make maters worse the tape covering every inch of her below the neck constricted like a ... constricting animal thing. that monoxide dioxide was really messing with her.
     Applying the stuff was the most undignified ordeal of her young life. The Captain and Luch applied the tape in rings around her torso and extremities. Luchs made sure the strip ends overlapped a lot. Then they reinforced the rings in the first layer with a layer of vertical strips. That was bad enough. But Luchs wanted to make sure the tape wouldn't peel up from curvy places and had puttied them up but good. It didn't help that Luchs was asexual. She'd blushed down to her toes. It didn't help when Luchs said there were establishments that would pay a few hundred credits to people submitting to such treatment.
     The Captain's dopeslap was perfectly timed and thump on Luch's head was most satisfying. They actually all managed a laugh.
     To make matters worse her nose was itchy. Her nose was itchy. She was having all manner of trouble breathing and now had the figure of a twelve year old boy and her neck felt like it measured 70 centimeters because that pulchtritude had to go somewhere.
     Her goddam nose itched. Was an itchy nose a symptom of suffocation/asphyxiation?
     She was at the damage control locker! The door opened to her frenzied yanking and curses. Cursing helped all manner of things. She grabbed a spacesuit and turned to scramble back to the bridge. The door was open and looked inviting even though the vacuum was as hard on the other side of it. The Captain and Luchs were waiting in the electronics hole and were pretty screwed if she messed up. Lugging the suit and the air hose she slipped and slid back to the bridge. At least they still had gravity. That alone indicated the hull couldn't be that badly holed.
     Sandoval threw the suit into the pilot seat. Her vision was blurring and not from a fogged mask as she reached for the hot key they'd set up. She hit it before she reeled and crashed to the deck.
     She woke up in the deluxe stateroom's master's bed. Usually the captain took the cabin over when he couldn't fill it.
     Luchs was sitting on the bed shaking her foot. "How are ya?" he asked. Sandoval stretched and saw tape still covered her arms. She moved her feet and realized it still covered most of her. She saw a very careful slit was made down her sternum letting her breathe. "I have the best vat steak in the galley cooking for you with your favorite sides. The Captain is still working on damage control but we're holding air. The beam went through the hull at stateroom three. There's a big hole on the outer hull and a nasty on on the hatch. He slapped patches on them and is welding the cabin's hatch shut."
     "Sounds good. Can I get up?" Sandoval said. She really was enjoying the bed though. Much better than a bunk.
     "Sure Sandy ... but here's the bad news: that tape has to come off you before it cuts off circulation."
     "Mmm ..."
     "On three ..." Luchs said.
     He yanked the first strip off on 'one'.
     The Captain heard her scream through one deck and his helmet.

From VACC TAPE by Rob Garitta (2017)

Scratching Your Nose

      But, in general, powered armor doesn't require practice; it simply does it for you, just the way you were doing it, only better.

     All but one thing—you can't scratch where it itches. If I ever find a suit that will let me scratch between my shoulder blades, I'll marry it.

From STARSHIP TROOPERS by Robert Heinlein (1959)

In the NASA Apollo spacesuits, the astronauts could simply scratch their itching nose on the chowlock. But the general problem is still there: how to allow an astronaut or an emergency worker access to the astronaut's body, without letting the breathing mix escape.

Doctors working in the space environment can give their space suited patient oral medication through the chowlock. Injectable medications are a problem. In science-fiction novels, space doctors stock their little black bags with large-calibre hypodermics. So if they have to do an emergency injection of some medication while both doctor and patient are in vacuum, the heavy-duty needle can penetrate the space suit. Of course any needle that can puncture a suit is going to be sheer agony penetrating one's skin, but you take what you can get. After injection the doctor will slap on an emergency seal patch over the hole. If the hypo has to hit a vein, the doctor is just going to have to do their best.

Urinating or defecating while wearing a suit is not going to be elegant. Slightly better than peeing down one's leg is using a hose and a diaper. And ever so slightly better than that is the perineal access port.

Two of the earliest lunar exploration space suit designs attempted to deal with this problem, abet awkwardly. Both the Republic Aviation and Grumman Moon Suits were based on the same concept. The head and torso of the suit was a large pressurized cabin. The arms and legs were conventional constant-volume space suit limbs attached to the cabins.

The clever part is that the astronaut can withdraw their arms from the suit limbs and use them inside the cabin. This allows them to eat their rations, scratch their back, bandage wounds, and answer the call of nature with a bit more finesse than using a diaper.

The Republic suit actually had a retractable tripod. When extended, the astronaut could rest the cabin on the tripod and sit down on the cabin base like a pressurized chair.

Like I said, this was an awkward solution. But it did go a long way toward solving the problem. It is hard to think of a better solution, short of a handwaving force-field spacesuit or something equally scifi. Or a full-blown space pod.


      SPACE SUITS of the future will be more like shelters than clothing. Short on style, but long on reliability, they'll contain their own life-support Systems. Once outside the spacecraft they'll be attached to ground-powered vehicles that will carry the astronaut and his supplies. During the Ice Age cavemen wrapped skins about them to keep from freezing to death. Today's survival manuals of the Army and other services stress the importance of clothing to maintain correct body temperature, protect against sun, prevent skin damage and the bite of poisonous insects.

     In outer space men's clothing will become much more important to him. It will protect him against added dangers of cosmic and solar radiation, extremes of heat and cold (lunar temperatures range more than 450 degrees Fahrenheit) vacuum conditions and particles streaking through space without atmosphere to burn them. Space suits of the future will be no ordinary flying suits. They'll be developed from astronaut clothing used in today's Mercury capsules. The torso suit is a closely fitted coverall with inner gas-retention ply of neoprene and an outer heat-reflective, aluminized nylon fabric; a helmet of resinous, impregnated fiber glass hard-shell with visor sealing and communication system; gloves with miniature finger lights; boots of aluminized, nylon fabric with tennis-shoe-type soles; and a cotton undergarment with long sleeves and legs.

     The space suit has become a compact version of the spacecraft cabin. Into it has been built a similar environment control system. Its basis is an air conditioner which is called a heat exchanger. Hot air, carbon dioxide and body odor leave the suit by a ventilation outlet at the back of the helmet, drawn into the heat exchanger by a water-cooled fan, purified and sent back by a hose from the oxygen tank to the suit waist. Fresh oxygen is forced into the suit's distribution ducts and carried to the limbs where it flows freely back over the body for cooling and pressurization.

     Several kinds of clothing will be worn during a space journey. During flight in a spacecraft, such as the Apollo on its way to the moon, astronauts will travel in a shirtsleeve environment, the same as the crews of the B-70. Astronauts will probably take turns wearing a space suit that will permit them to make outside repairs on the ship. When the crew reaches the moon they'll wear a space suit of more advanced design.

     The Lunar Exploration Suit, Model MK 1 has been developed by Space General Corporation for travel across the surface of the moon. It resembles a shelter because it must carry its own life-support system wherever it goes. The basic suit assembly weighs 60 pounds on earth, 10 pounds on the moon. It will carry a two-week food supply weighing 30 pounds; a two-hour oxygen supply, 24 pounds; battery, 24 pounds; communication equipment, 12 pounds; reading and miscellaneous material, 12 pounds. With an 180-pound astronaut, this suit will total 342 earth-pounds and 57 moon-pounds.

     Looking at this enormous suit from top to bottom, you see first a wide-domed headpiece with an identification light centered on top, V-shaped antennae, a built-in helmet camera and see-around faceplate that drops almost straight down to the shoulders to give the astronaut 360-degree vision. At collar height there is a bumper to protect the "windshield" and for another astronaut to grab in helping his buddy. At thigh level ground lights can be turned on. Boots are double-soled and vacuum-insulated.

     The astronaut will maneuver the suit much like a small tank. As he walks, he will use his arms inside to help the shoulder harness support the suit. He will operate dials and knobs on the control panel below the windshield for his life-support functions, to control the suit's cooking facilities, tune his radio and operate electronic equipment. From his "dashboard" inside the suit, he will also be able to manipulate a ground-powered vehicle which will support him with additional oxygen and supplies during exploration. This "Moonmobile" is technically called the Lunar Exploration Vehicle (2 man) MK I. It has a 20-foot umbilical which delivers oxygen and power to the space suit. The astronaut may walk with the vehicle, or he may choose to ride. If he rides, he hooks himself onto one end of the Moonmobile with support trunnions located on each side of his space suit. A mechanism on the vehicle will lift him off the ground and carry him in an upright position at five miles an hour. Also, when supported by the vehicle, the astronaut can easily shift his weight much the same as in a lean-back chair. In this way he can tilt the suit horizontally for sleeping. It is padded down the back so as to be reasonably comfortable under reduced lunar gravity. The multi-purpose support trunnions not only provide a means of support aboard the Moonmobile, but they can serve as a point of attachment for "flying belts." They can also be used to hoist this "detachable man-propelled cabin of a Moonmobile" into the spaceship.

     There are advantages to integrating the hard-shell space suit into the configuration of a vehicle such as a Moonmobile. If the astronaut must move away from his supply vehicle, the umbilical can be disconnected. Then the suit's self-contained oxygen and power supply will permit it to operate independently until the oxygen is used. In exploration missions this is important. When each crewman is contained within his own suit. the failure of one will not affect the others, In this way space clothing will provide each astronaut a better chance for survival.

From SPACE CLOTHING by Col. Bill Dunkerley (1964)

Handwavium Suits

These are science fictional ultra-high-tech space suits powered by handwavium. The accuracy of space suits in science fiction was very much hit or miss. The low budget show Space Academy had "Life Support Bracelets" and the Star Trek Animated series had force-field based "Life Support Belts" as a cheapskate way to avoid the special effect expense of renting or drawing an actual space suit.


Feeling as naked as a peppermint soldier in her transparent film wrap, Dr. Ulla Hillstrøm watched a flying cloak (alien animal native to Titan) swirl away toward the black horizon with a certain consequent irony. Although nearly transparent itself in the distant dim arc-light flame that was Titan's sun, the fluttering creature looked warmer than what she was wearing, for all that reason said it was at the same minus 316° F. as the thin methane it flew in. Despite the virus space-bubble's warranted and eerie efficiency, she found its vigilance—itself probably as nearly alive as the flying cloak was—rather difficult to believe in, let alone to trust.

The machine—as Ulla much preferred to think of it—was inarguably an improvement on the old-fashioned pressure suit. Made (or more accurately, cultured) of a single colossal protein molecule, the vanishingly thin sheet of life-stuff processed gases, maintained pressure, monitored radiation through almost the whole of the electromagnetic spectrum, and above all did not get in the way. Also, it could not be cut, punctured or indeed sustain any damage short of total destruction; macroscopically it was a single, primary unit, with all the physical integrity of a crystal of salt or steel.

If it did not actually think, Ulla was grateful; often it almost seemed to, which was sufficient. Its primary drawback for her was that much of the time it did not really seem to be there.

Still, it seemed to be functioning; otherwise Ulla would in fact have been as solid as a stick of candy, toppled forever across the confectionery whiteness that frosted the knife-edged stones of this cruel moon, layer upon layer. Outside—only a perilous few inches from the lightly clothed warmth of her skin—the brief gust the cloak had been soaring on died, leaving behind a silence so cataleptic that she could hear the snow creaking in a mockery of motion. Impossible though it was to comprehend, it was getting still colder out there. Titan was swinging out across Saturn's orbit toward eclipse, and the apparently fixed sun was secretly going down, its descent sensed by the snows no matter what her Earthly sight, accustomed to the nervousness of living skies, tried to tell her. In another two Earth days it would be gone, for an eternal week.

From HOW BEAUTIFUL WITH BANNERS by James Blish (1966)

She felt her way across the command module in absolute darkness, guided by the technological intuition her Ghost implants granted her, pulling herself along solely by her hands, while her feet floated out behind her. The bulkheads and surfaces were all covered with smooth velvet and fur that was easy to grip. Cushions, meal containers and pieces of discarded clothing whirled in eddies created by her passage, colliding with her suddenly and unavoidably in the darkness.

The only sound Dakota could hear was her own panicked breathing, matched by the adrenaline thud of her heart. Convinced the life support was about to collapse, she activated her filmsuit. It spilled out of her skin from dozens of artificial pores, a flood of black ink that cocooned and protected her inside her own liquid spacesuit, growing transparent over her eyes so as to display the darkened space around her in infrared.

Instrument panels glowed eerily with residual heat, and she saw hotspots where her naked flesh had touched heat-retaining surfaces, making it easier for her mind to wander into fantasies of being trapped on a deserted, haunted ship.

She was still getting used to the filmsuit she’d stolen from the Bandati during her visit to Corkscrew. It coated her naked flesh just like a thick layer of dark chocolate, protecting her from the vacuum and radiation just millimetres from her skin. It smoothed out her features, making her appear, to any potential observer, like an animated doll. Her lungs were stilled, their function temporarily taken over by microscopic battery units she’d had implanted in her spinal column. She was, in effect, a one-woman spaceship, though there was a clear limit to just how long the suit would keep functioning before the batteries needed recharging.

Dakota activated her filmsuit and, under her clothes, it coated her bare flesh within moments. Her lungs shut down automatically and, as always, it took her a moment to get over the sensation that she was suffocating.

Dakota entered an airlock and shed all her clothes, placing them in a satchel before slinging it over her bare shoulders. Her filmsuit then emerged and coated her flesh. Once it had sealed her lungs, anus, vagina and nasal cavities, she began to run the depressurization cycle. A few moments later a deep silence fell, then the external door swung open to reveal the vast emptiness beyond the Hyperion’s hull.

Protective molecular filters formed themselves out of the filmsuit and coalesced over her irises, momentarily magnifying the distant bright mass of faraway Mesa Verde until surface details stood out in near-hallucinatory detail before they balanced out. The stars looked like a fine dusting of diamonds across the universe.

The air got thin enough for Dakota’s filmsuit to activate automatically, swallowing her bruised and battered body in its oily embrace. She felt Corso’s hand jerk away for an instant, as it touched his skin where he clung on to her.

From STEALING LIGHT by Gary Gibson (2007)

      He unbuckled, feeling light-headed as he stood for the first time in Martian gravity. He had adapted entirely too well to the one-gee of the Deimos ring, constructed for the comfort of Earthside tacticians. He went to the emergency locker and found a mask which slivered eagerly across his face; another for Voi. They plugged in air-tanks and went to the shuttle’s door. This time when it sphinctered open there was a glistening membrane stretched across the doorway, a recently licensed item of Demarchist technology. Clavain pushed through the membrane and the stuff enveloped him with a wet, sucking sound. By the time he hit the dirt the membrane had hardened itself around his soles and had begun to contour itself with ribs and accordioned joints, even though it stayed transparent.

     Voi came behind him, gaining her own m-suit.

     They loped away from the crashed shuttle, toward the dyke. The mask felt clammy against his face. The air at the base of the Great Wall was technically breathable even now, but there seemed no point in taking chances when speed was of the essence. His feet scuffed through the topsoil, and while he seemed to be crossing ground, the dyke obstinately refused to come any closer.

     When the armoured door to the hangar was shut the Conjoiners attacked his m-suit with enzymic sprays. The sprays digested the fabric of the m-suit in seconds, leaving Clavain wheezing in a pool of slime. Then a pair of Conjoiners helped him unsteadily to his feet and waited patiently while he caught his breath from the mask.

From GREAT WALL OF MARS by Alastair Reynolds (2000)

      Villimy saw other Nats below in the forest of fronds. Startled, she saw Techs in the water as well. At first, she thought that they were a third, water-breathing species, but then noticed the shimmering, transparent coating that covered their bodies. The membrane undoubtedly served to allow them to breath under water. She could see a bubble rising and falling on their backs in time with their slow respiratory rate.

     Near the hatch stood a square framework attached to a small humming machine. The frame looked like a window pane with a shimmering, transparent film. As she watched, one of the men moved around and stepped through the frame. The transparent film formed around the man, broke loose and snapped back into place undisturbed. The man walked on, now covered by the same transparency she had seen the Techs wearing in the reefs near Yeld. The man walked directly through the open hatch and dropped with a splash into the choppy waters outside.
     A second man repeated the process and left by way of the hatch, but the remaining two turned to watch her as she hesitantly approached to inspect this unique technological item. They stepped back, a gesture that gave her permission to satisfy her curiosity.
     When she reached out a hand to touch the film, it gave beneath her hand, a dry, but slick and tough plastic substance. She put her whole arm through the frame. The material clung to her, very elastic and forming a thick, even coating on her arm. Withdrawing her arm, the material returned to a taunt, flat surface. She noticed small holes in the frame that replenished the material whenever someone stepped through and walked off with the coating.

     She sensed one of the men stepping behind her, but paid him no mind. When he rushed forward to shove her through the frame, Villimy leaped out of his reach at the first touch of his hands on her body. But she leaped straight away from him, through the sheet of transparency and knew even as she jumped that that was exactly what the man had intended. The clear film snapped into place over her face. For a panicky instant she clawed at the obstruction covering her mouth and nostrils. Her fingers just slid across the stuff covering her face. The second, more successful shove sent her reeling through the open hatch and into darkness. She struck water and sank.
     Floundering in horror, she reflexively gasped for breath. And breathed. Without effort. She took several gasping breaths before forcing herself to relax. They hadn't meant to harm her, just to get her into the water for some reason. Her large, golden eyes dilated in the darkness. Light rippled on the surface of the water overhead. Darkness cloaked the depths beneath her.
     A human shape moved in front of her and then another, each with the shiny coating somehow maintaining a layer of fresh air close to the skin. As she breathed, she could feel the rush of air flow from around the sides of her neck. The men were pointing to something below her. She looked down in time to see a two-man sub approaching.

     Before she entered the hatch, she saw the two-man subs breaking away in all directions. One of the Nats guided her through the water-filled cockpit and into a rear chamber. The hatch closed behind her.
     "We must hurry," an internal voice said. "Hold onto the railings lining the chamber."
     Villimy held on. The sub nosed straight down and dived.
     "Pressure will increase," the voice told her. "Your chamber will be filled with air. A light will dissolve the transparency. When the water is gone, hold your breath and close your eyes until this is accomplished. Do you understand?"
     She couldn't breathe the instant the water level fell past her shoulders. When the hiss of air faded, an intense, red light flooded the chamber. Villimy jammed her eyes shut against it. The light felt hot and the transparency loosened and fell away. It formed a sticky mass at her feet, then dissolved to the consistency of water and drained off. The red light dried the chamber and her clothing before fading out. Her ears popped as the air pressure climbed.

     Villimy's ears popped again and did so at regular intervals. She felt Linder's growing alertness as they approached their destination.
     "It is time to acquire a fresh transparency," Linder said after nearly an hour.
     A rectangular frame lowered from a slot in the ceiling, filled with a shimmering taut film. The frame touched the deck and stopped, but Villimy hesitated before stepping through.
     "Water will immediately flood the compartment," Linder said. "Your breathing will not be seriously interrupted."
     "A part..." Her voice sounded odd.
     "It is the air you breathe to prevent harm caused by the pressures we endure at this depth. Speak in your thoughts."
     "A part of me still feels like I'm going to drown."
     "We can imagine," Linder said in sympathy. "We fear air as you fear water."

     Villimy took a deep breath, closed her eyes and stepped forward through the frame. She barely felt the film stretch across her face. She felt the rush of water as a slight pressure rising from her feet. She breathed cautiously before opening her eyes. The hatch to the control cabin had opened.

From HYDRABYSS RED by William Tedford (1981)

(ed note: Peewee is an eleven year old girl with a genius level intellect. Kip is a seventeen year old boy who won a Goodyear space suit in a contest. He named it Oscar, and has a habit of "talking" to it and imagining it answering back. Kip has been injured by the cold on Pluto, helping an alien (the "Mother Thing") from a highly technologically advanced culture who have their main base on Vega. Both Kip and Peewee have been taken to Vega 5. Kip in a sort of autodoc bed helping him heal.)

      Peewee showed up one day full of bubbles. She posed like a mannequin. “Do you like my new spring outfit?”
     She was wearing silvery tights, plus a little hump like a knapsack. She looked cute but not glamorous, for she was built like two sticks and this get-up emphasized it.
     “Very fancy,” I said. “Are you learning to be an acrobat?”
     “Don’t be silly, Kip; it’s my new space suit—a real one.”
     I glanced at Oscar, big and bulky and filling the closet and said privately, “Hear that, chum?”
     (“It takes all kinds to make a world.”)
     “Your helmet won’t fit it, will it?”
     She giggled. “I’m wearing it.”
     “You are? ‘The Emperor’s New Clothes’?”
     “Pretty close. Kip, disconnect your prejudices and listen. This is like the Mother Thing’s suit except that it’s tailored for me. My old suit wasn’t much good—and that cold cold (on Pluto) about finished it. But you’ll be amazed at this one. Take the helmet. It’s there, only you can’t see it. It’s a field. Gas can’t go in or out.” She came close. “Slap me.”
     “With what?”
     “Oh. I forgot. Kip, you’ve got to get well and up off that bed. I want to take you for a walk.”
     “I’m in favor. They tell me it won’t be long now.”
     “It had better not be. Here, I’ll show you.” She hauled off and slapped herself. Her hand smacked into something inches from her face.
     “Now watch,” she went on. She moved her hand very slowly ; it sank through the barrier, she thumbed her nose at me and giggled.
     This impressed me—a space suit you could reach into! Why, I would have been able to give Peewee water and dexedrine and sugar pills when she needed them. “I’ll be darned! What does it?”

(ed note: When Kip got his suit, he purchased from the local druggest the standard medications a Goodyear space suit carried inside the helmet. Of course no sane pharmacist nowadays would even dream of selling amphetamines to a high-school kid, space-suit or not)

     “A power pack on my back, under the air tank. The tank is good for a week, too, and hoses can’t give trouble because there aren’t any.”
     “Uh, suppose you blow a fuse. There you are, with a lungful of vacuum.”
     “The Mother Thing says that can’t happen.”
     Hmm—I had never known the Mother Thing to be wrong when she made a flat statement.
     “That’s not all,” Peewee went on. “It feels like skin, the joints aren’t clumsy, and you’re never hot or cold. It’s like street clothes.”
     “Uh, you risk a bad sunburn, don’t you? Unhealthy, you tell me. Unhealthy even on the Moon.”
     “Oh, no! The field polarizes. That’s what the field is, sort of. Kip, get them to make you one—we’ll go places!”

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)

(ed note: the protagonist is on a little vacation. On the surface of the planet Venus. Yes, the temperature is 462 °C and the atmospheric pressure is 92 times that of Terra. But he has a force field suit)

It’s quiet. You begin to miss the sound of your own breathing, and if you think about that too much, you begin to wonder why you aren’t breathing. You know, of course, except the hindbrain, which never likes it at all. It doesn’t matter to the autonomic nervous system that your Venus-lung is dribbling oxygen directly into your bloodstream; those circuits aren’t made to understand things; they are primitive and very wary of improvements. So I was plagued by a feeling of suffocation, which was my medulla getting even with me, I guess.

I was also pretty nervous about the temperature and pressure. Silly, I know. Mars would kill me just as dead without a suit, and do it more slowly and painfully into the bargain. If my suit failed here, I doubt if I’d have felt anything. It was just the thought of that incredible pressure being held one millimeter away from my fragile skin by a force field that, physically speaking, isn’t even there. Or so Ember told me. She might have been trying to get my goat. I mean, lines of magnetic force have no physical reality, but they’re there, aren’t they?

The Venusians use null fields for just about everything. Rather than try to cope with a technology that must stand up to the temperature and pressure extremes, they coat everything in a null field and let it go at that. The balloon on the cycle (sort of a bicycle pedal-powered dirgible) was nothing but a standard globular field with a discontinuity at the bottom for the air heater. The cycle body was protected with the same kind of field that Ember and I wore, the kind that follows the surface at a set distance. The tent was a hemispherical field with a flat floor.

It simplified a lot of things. Airlocks, for instance. What we did was to simply walk into the tent. Our suit fields vanished as they were absorbed into the tent field. To leave one need merely walk through the wall again, and the suit would form around you.

Sometime that day we passed a tributary of the Reynolds-wrap River. It showed up as a bright line in my right eye, as a crusted, sluggish semiglacier in my left. Molten aluminum, I was told.

And down we went. This wasn’t too hard. Ember set the example by sitting down in a smooth place and letting go. Malibu was close behind her, squealing happily as he bounced and rolled down the slippery rock face. I saw Ember hit a bump and go flying in the air to come down on her head. Her suit was already stiffened. She continued to bounce her way down, frozen in a sitting position.

I followed them down in the same way. I didn't much care for the idea of bouncing around like that, but I cared even less for a slow, painful descent. It wasn’t too bad. You don't feel much after your suit freezes in impact mode. It expands slightly away from your skin and becomes harder than metal, cushioning you from anything but the most severe blows that could bounce your brain against your skull and give you internal injuries. We never got going nearly fast enough for that.

I had a radio transmitter in my throat and a receiver in my ear. That’s how you talk on Venus; you subvocalize and people can hear you.

From IN THE BOWL by John Varley (1975)

      “They just got another sighting,” she thought, but it wasn’t her own thought. It was the voice of Equinox. Equinox was Parameter’s companion, her environment, her space suit, her alter ego; her Symb. She looked in the direction she had come from.
     Nothing that Parameter saw was real; all was illusion. Her head was completely enclosed in the thick, opaque substance of Equinox, and all the sensory data she received was through the direct connection from Equinox’s senses into her own brain. Much of this information was edited and embellished in ways that made it easier for Parameter to interpret.
     So it was that when she looked down at herself she saw not the dark-green surface of Equinox, but her own brown skin. She had asked for that illusion long ago, when it had become a matter of some importance to her to believe she still had her own body. The illusion was flawless. She could see the fingerprints on her hand, the mole on her knee, the color of her nipples, the sentimental scar on her forearm, all illuminated by the soft diffusion of light from the Rings. But if she tried to touch herself, her hand would be stopped while still a good distance from what she saw as the surface of her body. Equinox was invisible to her, but she was certainly there.
     When the rock was close enough to see as an object rather than a simulated projection, she rotated until her legs pointed at it. She soaked up the shock of the landing, then began to scuttle over the surface in a manner quite astonishing, and with a speed not to be believed. She moved with the coordinated complexity of a spider, all four limbs grasping at the rock and ice.
     To an observer, she was a comical sight. She looked like a barbell with arms and legs and a bulge at the top that just might be a head. There were no creases or sharp lines anywhere on the outer surface of Equinox; all was gentle curves, absolutely featureless except for short claws on the hands and feet. At the ends of her legs were grasping appendages more like oversized hands than feet. And her legs bent the wrong way. Her knees were hinged to bend away from each other.
     But she swarmed over the rock with effortless ease.

     The Symb was a soft-looking greenish lump in the center of the room. With the best will in the world, Parameter could not see that it resembled anything so much as a pile of green cow manure. It was smaller than she had expected, but that was because it had no occupant. She was about to remedy that.
     She stumped over to it and looked down dubiously. “Just touch it, that’s all?” she said. Now that it had come to it, she was having second thoughts.
     “That’s right. The Symb will do the rest. It won’t be easy. You’ll have between six weeks and three months of sensory deprivation while the personality develops. You’d go crazy in two days, but you won’t be alone. All you’ll have to hang on to will be the mind of the Symb. And it’ll be a baby, hard to get along with. You’ll grow up together.”
     She took a deep breath, wondering why she was so reluctant. She had done things easily that were much more repulsive than this. Perhaps it was the dawning realization that this would be much more than a simple lark. It could last a long time.
     “Here goes.” She lifted her leg and touched one of her ped-fingers to the blob (people who live in free fall have their feet genetically replaced by hands, which are called "peds"). It stuck. The Symb slowly began stirring.
     The Symb was . . . warm? No, at first she thought so, but it would be more accurate to say it was no temperature at all. It was thirty-seven degrees: blood temperature. It oozed up her leg, spreading itself thinner as it came. In a short time it was inching up her neck.
     “Inhale,” Bushwacker advised. “It’ll help a little.”
     She did so, just as the Symb moved over her chin. It moved over her mouth and nose, then her eyes.
     There was a moment of near-panic when part of her brain told her she must take a breath, and she dutifully tried to. Nothing happened, and she wanted to scream. But it was all right. She didn’t need to breathe. When she opened her mouth the Symb flowed down her throat and trachea. Soon her lungs were filled with the interface tissue whose function it was to put oxygen in her blood and remove carbon dioxide. It filled her nasal passages, slithered up the eustachian tube to her inner ear. At that point she lost her balance and fell to the floor. Or she thought she did; she could no longer be sure. She had felt no impact. A wave of dizziness swept over her; she wondered what a Symb would do about vomiting. But it didn’t happen, and she suspected it never would.
     It was a shock, even though she had expected it, when the Symb entered her anus and vagina. Not a bad shock. Rather a thrill, actually. It filled the spaces in her uterus, wound into the urethra to fill the bladder, then up the ureter to mingle with the kidneys. Meanwhile another tendril had filled the large and small intestine, consuming the nutrients it found there, and joined with the tendril coming from her mouth. When it was done, she was threaded like the eye of a serpentine needle, and was revealed to any that could see as a topological example of a torus.
     The silence closed in. It was absolutely quiet for a period of time she was powerless to measure, but couldn’t have been longer than five minutes.
     The obvious place where the human brain is accessible without violating any solid membranes is alongside the eyeball and through the supraorbital foramen. But the Symb would not be able to get a very substantial tendril through in the tight confines of the eye. So the genetic engineers, elaborating on the basic design for oxygen breathers received over the Ophiuchi Hotline, had given the Symb the capability of forcing an entry through the top of the skull.
     Parameter felt a twinge of pain as a two-centimeter hole was eaten in the top of her head. But it subsided as the Symb began to feel out the proper places to make connections. The Symb was still a mindless thing, but was guided infallibly by the carefully designed instinct built into it.
     Suddenly she was surrounded by fear; childish, inconsolable fear that frightened her out of her wits but did not come from her mind. She fought it, but it only became more insistent. In the end, she abandoned herself to it and cried like a baby. She became an infant, sloughing off her seventy-odd years there in the impalpable darkness like they had never happened
.      There was nothing; nothing but two very lost voices, crying in the void.

     There had been a debate raging for centuries as to whether the Symbiotic Space-Environment Organisms were really a form of artificial intelligence. (Or alien intelligence, depending on your definition.) The people who lived in them were unanimously of the opinion that they were. But the other side — who were mostly psychologists — pointed out that the people who actually lived in them were in the worst possible place to judge. Whatever one’s opinion on the subject, it was based on personal prejudice, because there could be no objective facts.
     The Symbs were genetically tailored organisms that could provide a complete, self-contained environment for a single human being in space. They thrived on human waste products: urine, feces, heat, and carbon dioxide.
     They contained several chlorophyll-like enzymes and could accomplish photosynthesis utilizing the human’s body heat, though at a low efficiency. For the rest of the energy needs of the pair, the Symb could use sunlight. They were very good at storing energy in chemical compounds that could be broken down later at need. Together with a human, a Symb made a self-contained heat engine. They were a closed ecology, neither host nor parasite: a symbiosis.
     To the human being, the Symb was a green pasture, a running brook, a fruit tree, an ocean to swim in. To the Symb, the human was rich soil, sunshine, gentle rain, fertilizer, a pollinating bee. It was an ideal team. Without the other, each was at the mercy of elaborate mechanical aids to survive. Humans were adapted to an environment that no longer existed for their use in a natural state; wherever humans lived since the occupation of the Earth, they had to make their own environment. Now the Symbs were to provide that environment free of charge.
     But it hadn’t worked that way.
     The Symbs were more complicated than they looked. Humans were used to taking from their surroundings, bending or breaking them until they fit human needs. The Symbs required more of humanity; they made it necessary to give.
     When inside a Symb, a human was cut off entirely from the external universe. The human component of the symbiosis had to rely on the Symb’s faculties. And the sensory data were received in an unusual way.
     The Symb extended a connection directly into the human brain and fed data into it. In the process, it had to get tied up in the brain in such a way that it could be difficult to say where human left off and Symb began. The Symb reorganized certain portions of the human brain, freeing its tremendous potential for computation and integration, and using those abilities to translate the sensory data into pictures, sounds, tastes, smells, and touches, going directly through the sensorium. In the process, a mind was generated.
     The Symb had no brain of its own, it merely was able to utilize the human brain on a time-sharing basis, and utilize it better than its original owner had been able to. So it would seem impossible that it could have a mind of its own. But every Ringer in the system would swear it had. And that was the crux of the debate: Was it actually an independent mind, parasitically using the human brain as its vehicle for sentient thought, or was it merely schizophrenia, induced by isolation and projection?
     It was impossible to decide. Without a human inside it, there is nothing more helpless than a Symb. Without the human brain in combination with the genetic information and enzymatically coded procedures, the Symb can do no more than lie there inert like the green turd it so closely resembles. It has only rudimentary musculature, and doesn’t even use that when alone. There is no good analogy for a Symb without a human; nothing else is so dependent on anything else.
     Once combined with a human, the pair is transformed, becoming much more than the sum of its parts. The human is protected against the harshest environment imaginable. The livable range with a Symb extends from just outside the orbit of Earth (radiation limit) to the orbit of Neptune (sunlight limit). The pair feed each other, water each other, and respirate each other. The human brain is converted into a supercomputer. The Symb has radio and radar sender and receiver organs, in addition to sensors for radiation and the electromagnetic spectrum from one thousand to sixteen thousand angstroms. The system can gain mass by ingesting rock and ice and the Symb can retain the valuable minerals and water and discard the rest. About all the pair cannot do is change velocity without a chunk of rock to push against. But it is a small matter to carry a rocket thruster instead of the whole apparatus of a space suit. In the Rings, they didn’t even do that. The Symb could manufacture enough gas for attitude control. For major velocity changes, the Ringers (people who live in Saturn's Rings) carried small bottles of compressed gas.
     So why weren’t all humans in space installed in Symbs?
     The reason was that the Symbs needed more than most people were willing to give. It wasn’t a simple matter of putting it on when you needed it and taking it off later. When you took off your Symb, the Symb ceased to exist.
     It was probably the heaviest obligation a human ever had to face. Once mated with a Symb, you were mated for life. There had never been a closer relationship; the Symb lived inside your mind, was with you even when you slept, moving independently through your dreams. Compared with that, Siamese twins were utter strangers who pass in the night.
     It was true that all the humans who had ever tried it swore they hadn’t even been alive before they joined their Symb. It looked attractive in some ways, but for most people the imagined liabilities outweighed the gains. Few people are able to make a commitment they know will be permanent, not when permanent could mean five or six hundred years.
     After an initial rush of popularity the Symb craze had died down. Now all the Symbs in the system were in the Rings, where they had made possible a nomadic existence never before known.
     Ringers are loners by definition. Humans meet at long intervals, mate if they are of a mind to, and go their separate ways. Ringers seldom see the same person twice in a lifetime.
     They are loners who are never alone.

     It was a warm day in the Upper Half. But then it was always a warm day, though some were warmer than others.
     Ringography is an easy subject to learn. There are the Rings: Alpha, Beta, and the thin Gamma. The divisions are called Cassini and Encke, each having been created by the gravitational tug-of-war between Saturn and the larger moons for possession of the particles that make up the Rings. Beyond that, there is only the Upper Half and the Lower Half, above and below the plane, and Inspace and Outspace. The Ringers never visited Inspace because it included the intense Van Allen-type radiation belts that circle Saturn. Outspace was far from the traveled parts of the Rings, but was a nice place to visit because the Rings were all in one part of the sky from that vantage point. An odd experience for children, accustomed from birth to see the sky cut in half by the Rings.
     Parameter was in the Upper Half to feed on the sunlight that was so much more powerful there than in the Rings. Equinox was in her extended configuration. The pair looked like a gauzy parabolic dish, two hundred meters across. The dish was transparent, with veins that made it look like a spider web. The illusion was heightened by the small figure spread-eagled in the center of it, like a fly. The fly was Parameter.
     It was delicious to float there. She looked directly at the sun, which was bright even this far away and would have burned her eyes quickly if she had been really looking at it. But she saw only a projection. Equinox’s visual senses were not nearly as delicate as human eyes.
     The front of her body was bathed in radiance. It was highly sensual, but in a new way. It was the mindless joy of a flower unfolding to the sun that Parameter experienced, not the hotter animal passions she was used to. Energy coursed through her body and out into the light-gathering sheets that Equinox had extended. Her mind was disconnected more completely than she would have believed possible. Her thoughts came hours apart, and were concerned with sluggish, vegetable pleasures. She saw herself as naked, exposed to the light and the wind, floating in the center of a silver circle of life. She could feel the wind on her body in this airless place and wondered vacantly how Equinox could be so utterly convincing in the webs of illusion she spun.
     There was a sudden gust.
     “Parameter. Wake up, my darling.”
     “There’s a storm coming up. We’ve got to furl the sails and head into port.”
     Parameter felt other gusts as she swam through the warm waters back to alertness.
     “How far are we from the Ring?”
     “We’re all right. We can be there in ten minutes if I tack for a bit and then use a few seconds of thrust.”
     In her extended configuration, Equinox was a moderately efficient solar sail. By controlling the angle she presented to the incoming sunlight she could slowly alter velocity. All Parameter had to do was push off above or below the Rings in a shallow arc. Equinox could bring them back into the Rings in a few days, using solar pressure. But the storm was a danger they had always to keep in mind.
     It was the solar wind that Equinox felt, a cloud of particles thrust out from the sun by storms beneath the surface. Her radiation sensors had detected the first speed-of-light gusts of it, and the dangerous stuff would not be far behind.
     Radiation was the chief danger of life in the Rings. The outer surface of a Symb was proof against much of the radiation the symbiotic pair would encounter in space. What got through was not enough to worry about, certainly never enough to cause sickness. But stray high-energy particles could cause mutations of the egg and sperm cells of the humans.
     The intensity of the wind was increasing as they furled their sails and applied the gas thrusters.
     “But you would tell me, wouldn’t you?” (Parameter asked)
     “If you want me to. But it isn’t important. No more than the daily control I exert over any of your other bodily processes.”
     “If you say so.”
     “I say so. Don’t worry, I said. You just handle the motor control and leave the busy work to me. Things don’t seem quite real to me unless they’re on the molecular level.

     “I think it’s time we tried out the new uterus.”
     “I think you’re right.”
     “If that thing out there is a male, we’ll do it.”
     Equinox had in her complex of capabilities the knack of producing a nodule within her body that could take a cloned cell and nurture it until it grew into a complete organ; any organ she wished. She had done that with one of Parameter’s cells. She removed it, cloned it, and let it grow into a new uterus. Parameter’s old one had run out of eggs long ago and was useless for procreation, but the new one was brimming with life.
     She had operated on her mate, taking out the old one and putting in the new. It had been painless and quick; Parameter had not even felt it.

From EQUINOCTIAL by John Varley em>(1977)

(ed note: the Symbs are an organism that enters into a symbiotic relationship with a human being. They are intelligent. The resulting composite creature can happily live in the vacuum of space as long as it has access to sunlight and some sort of regolith, and has a lifespan of several hundred years. The Symbs were genetically engineered by humans using information obtained from aliens via the Ophiuchi Hotline)

      Of all the things received over the Ophiuchi Hotline (an extraterrestrial technology information broadcast), none is more wonderful than the symb. In the early part of the third century, symbs were seen as the salvation of the human race. Futurists saw the day when each human would be paired with a symb partner and forever free of reliance on airlocks, hydroponic farming, and recycled water. Each human would be a tiny model of lost Earth, free to roam the solar system at will.
     It's easy to see what inspired the optimism. The symmetry of the concept is overwhelming. Each human-symb pair is a closed ecology, requiring only sunlight and a small amount of solid matter to function. The vegetable symb gathers sunlight in space, using it to convert human waste and carbon dioxide into food and oxygen. At the same time it protects the fragile human from vacuum and the extremes of heat and cold. The symb's body extends into the lungs and through the alimentary canal. Each side feeds the other.
     What we didn't bargain for is the mind of the symb. Since it has no brain, a symb is nothing but a lump of artificial organic matter until it comes in contact with a human. But upon permeating the nervous system of its host it is born as a thinking being. It shares the human brain. The early experimenters learned that, once in, the symb was there to stay. Since that time relatively few have opted to surrender their mental privacy in exchange for Utopia in the Rings (of Saturn).
     But out of the disappointment we have been given a precious gift. Ring society is not human society. We live in rooms and corridors; they have all of space. We each have the right to be the mother of one child in our lifetimes; they breed like bacteria. We are islands; they are paired minds. It is a relationship that is difficult to imagine.

(ed note: Parameter is a human, Solstice is her symb, together they form the partner Parameter/Solstice.)

     Parameter floated over a golden desert that no horizon could contain. She faced the sun, which was a small but very bright disc just to anti-spinward of Saturn. Satum itself was a dark hole in space, edged by a razored crescent with the sun set in it like a precious stone.
     She saw none of this. She perceived the sun as a pressure and a wind, and Satum as a cold, deep well that pulled.
     The sunrise had been delicious. She could still taste the flavors of it flowing through the wafer-thin part of her body that had opened to receive it. She was a sunflower.
     Sunflower mode was a lazy, vegetable time. Parameter had Solstice, her symb, disconnect the visual centers of her brain so she could savor the simple pleasures of being a plant. Her arms were spread wide to the light and her feet were planted firmly in the fertile soil that was her symb. It was a good time.
     Seen from the outside, Parameter was the center of a hundred-meter filmy parasol, slightly parabolic. She was a spider sitting in the middle of a frozen section of soap bubble, but the section was shot through with veins, like the inner surface of an eyeball. Fluids pumped through the veins, some milky, some deep red, others purplish-brown. From a point near Parameter's navel a thin stalk extended, with a fist-sized nodule at the end of it. The nodule was at the focus of the parabola and received the small percentage of sunlight that was reflected from the sunflower. It was hot there, a steamy center for Parameter to revolve around. In the nodule and in the capillaries of the sunflower, chemical reactions were going on.
     Activity in her brain was damped down to almost nothing, interrupted only by the passing peaks of Solstice, who never went completely to sleep.
     "Parameter." It was not a voice, even when Parameter was more fully conscious. It was words forming in her head, like thoughts, but they were not her own thoughts.
     “ (Recognition; slight reproach; receptivity)"
     "Come on. Wake up."
     "What is it?" Coming awake was effortless.
     “Are you ready for vision now?"
     "Sure. Why not?"
     Solstice, functioning as a switchboard in the back of the cerebrum, closed the contacts that would allow Parameter's visual cortex to communicate with her forebrain: She saw.
     “What a lovely moming."
     “Yeah. Very nice. Wait till you see the morning papers. You won't be so happy."
     “Can it wait? Why ruin it?" Parameter felt no sense of urgency. It had been a century since she felt rushed.
     “Sure. Let me know when you're up to it."
     Parameter communicated wry amusement to her symb. (Picture of herself buckling on sword, dagger, donning brass helmet and picking up embossed shield.) Solstice responded. (Picture of Parameter climbing a staircase, gazing at the stars, failing to see she was reaching for a top step that wasn't there.)
     Parameter stretched, causing the filmy parasol to undulate slowly. She made tight flsts of all four hands—she had no feet, having surgically replaced them with oversized hands at the time of her pairing—then spread twenty fingers. One hand caught her attention. It was pale, but was turning pinker as she watched. She had the coloring of an albino; the skin under her nails was amber, turning quickly to orange. Solstice was packing up, pumping liquids around, getting ready to move.
     Nothing she saw was real. Her eyes were protected behind the opaque substance of Solstice; no light had fallen on her retinas in over seven years. Had she looked at the sun with her eyes, as she seemed to be doing, cells would have been destroyed. What she saw was the product of nerve impulses sent to different areas of her brain by Solstice's sensory receptors. But it looked to her as though she were floating naked in space, feeling the raw sunlight on her body. The illusion was complete.
     "Okay. What's up?"

From THE OPHIUCHI HOTLINE by John Varley (1977)

(ed note: Barnum and Baily are Partners, that is, Barnum is a human being merged with Baily. The latter is a "symb", an intelligent plant creature who is symbiotically merged with Barnum's body. Anyway, such Partners live around Saturn's rings and are inspired to compose music. When they do, they travel to sell their composition to a producer. They have traveled to the firm of Ragtime and Tympani. The lady Tympani works with them to translate their composition into musical notation because B&B wouldn't know a treble cleff if it flew straight up their behind. )

      Bailey didn’t answer, and Barnum didn’t pursue it. He knew the source of the symb’s uneasiness and dislike of the station on Janus. Bailey wanted to get their business over as soon as possible and get back to the Ring, where he felt needed. Here, in a corridor filled with oxygen, Bailey was physically useless.

     Bailey’s function in the symbiotic team of Bamum and Bailey was to provide an environment of food, oxygen, and water for the human, Barnum. Conversely, Barnum provided food, carbon dioxide, and water for Bailey. Barnum was a human, physically unremarkable except for a surgical alteration of his knees that made them bend outward rather than forward, and the oversized hands, called peds, that grew out of his ankles where his feet used to be. Bailey, on the other hand, was nothing like a human.

     Strictly speaking, Bailey was not even a he. Bailey was a plant, and Bamum thought of him as a male only because the voice in his head that was Bailey’s only means of communication sounded masculine. He had no shape of his own. He existed by containing Barnum and taking on part of his shape. He extended into Barnum’s alimentary canal, in the mouth and all the way through to emerge at the anus, threading him like a needle. Together, the team looked like a human in a featureless spacesuit, with a bulbous head, a tight waist, and swollen hips. A ridiculously exaggerated female, if you wish.

     “You might as well start breathing again,’’ Bailey said.
     “What for? I will when I need to talk to someone who’s not paired with a symb. In the meantime, why bother?’’
     “I just thought you’d like to get used to it.’’
     “Oh, very well. If you think it’s necessary.’’

     So Bailey gradually withdrew the parts of him that filled Barnum’s lungs and throat, freeing his speech apparatus to do what it hadn’t done for over ten years. Bamum coughed as the air flowed into his throat. It was cold! Well, it felt like it, though it was actually at the standard 72 degrees. He was unused to it. His diaphragm gave one shudder, then took over the chore of breathing as if his medulla had never been disconnected.

     “There,” he said aloud, surprised at how his voice sounded.
     “It never hurts to do a little testing.”

     “Let’s get this out in the open, shall we? I didn’t want to come here any more than you did, but you know we had to. Are you going to give me trouble about it until we leave? We’re supposed to be a team, remember?”

     There was a mental sigh from his partner.

     “I’m sorry, but that’s just it. We are supposed to be a team, and out in the Ring we are. Neither of us is anything without the other. Here I’m just something you have to carry around. I can’t walk, I can’t talk; I’m revealed as the vegetable that I am.”

     Barnum was accustomed to the symb’s periodic attacks of insecurity. In the Ring they never amounted to much. But when they entered a gravitational field Bailey was reminded of how ineffectual a being he was.

     “Here you can breathe on your own,” Bailey went on. “You could see on your own if I uncovered your eyes. By the way, do you ...”

     “Don’t be silly. Why should I use my own eyes when you can give me a better picture than I could on my own?”

     “In the Ring, that’s true. But here all my extra senses are just excess mass. What good is an adjusted velocity display to you here? The farthest thing I can sense is twenty meters off, and stationary.”

     “Listen you. Do you want to turn around and march back out that lock? We can. I’ll do it if this is going to be such a trauma for you.”

     There was a long silence, and Barnum was flooded with a warm, apologetic sensation that left him weak at his splayed-out knees.

     “There’s no need to apologize,” he went on in a more sympathetic tone. “I understand you. This is just something we have to do together, like everything else, the good along with the bad.”

     “I suppose it is.” He was silent again. He noticed that his throat was beginning to get sore with the unaccustomed effort of talking. No sooner had the thought been formed than he felt Bailey go into action. The internal tendril that had been withdrawn flicked up out of his stomach and lubricated his larynx. The pain died away as the nerve endings were suppressed.

     She sighed, but didn’t seem unhappy. “I figured as much. So few of you Ringers do. Honestly, if I i could ever figure out what it is that turns you people into artists I could get rich.”

     “The only way to do that is to go out in the Ring and see for yourself.” “Right,” she said, a little embarrassed. She looked away from the misshapen thing sitting in the chair. The only way to discover the magic of a life in the Ring was to go out there, and the only way to do that was to adopt a symb. Forever give up your individuality and become a part of a team. Not many people could do that.

     She recognized it and relaxed, taking a sandwich and eating it like she was starving.

     “She is starving, you dope,’’ Bailey said. “Or at least very hungry. She hasn’t had anything to eat for eight hours, and she doesn’t have a symb re-cycling her wastes into food and dripping it into her veins. So she gets hungry. Remember?”

     “I remember. I’d forgotten.” He looked at the pile of sandwiches. “I wonder what it would feel like to eat one of those?”

     “Like this.’’ Barnum’s mouth was flooded with the taste of a tuna salad sandwich on whole wheat. Bailey produced this trick, like all his others, by direct stimulation of the sensorium. With no trouble at all he could produce completely new sensations simply by shorting one sector of Barnum’s brain into another. If Barnum wanted to know what the taste of a tuna sandwich sounded like, Bailey could let him hear.

     ” I wonder if it would be the polite thing to eat one of them?”

     “Eat it, then,” Bailey sighed. “You’ll ruin my ecology schedules for months—what’ll I do with all that extra protein?—but why should you care about that?”

     Barnum laughed silently. He knew that Bailey could do anything he liked with it: ingest it, refine it, burn it, or simply contain it and expel it at the first opportunity. He reached for a sandwich and felt the thick substance of Bailey’s skin draw back from his face as he raised it to his mouth.

     While Bamum and Bailey were working with her, Tympani had to adjust her day and night cycles to fit with his biological processes. The Pair spent the periods of sunlight stretched out in Janus’ municipal kitchen.

     The kitchen was a free service provided by the community, one that was well worth the cost, since without it paired humans would find it impossible to remain on Janus for more than a few days. It was a bulldozed plain, three kilometers square, marked off in a grid with sections one hundred meters on an edge. Bamum didn’t care for it—none of the Pairs liked it much—but it was the best they could do in a gravity field.

     No closed ecology is truly closed. The same heat cannot be re-used endlessly as raw materials can. Heat must be added, energy must be pumped in somewhere along the line to enable the plant component of the cycle to synthesize the carbohydrates needed by the animal component. Bailey could use some of the low-level heat generated when Barnum’s body broke down these molecules, but that process would soon lead to ecological bankruptcy.

     The symb solution was photosynthesis, like any other plant, though the chemicals Bailey employed for it bore only a vague resemblance to chlorophyl. Photosynthesis requires large amounts of plant surface, much more than is available on an area the size of a human. And the intensity of sunlight at Saturn’s orbit was only one hundredth what it was at Earth.

     Barnum walked carefully, along one of the white lines of the grid. To his left and right, humans were reclining in the centers of the large squares. They were enclosed in only the thinnest coating of symb; the rest of the symb’s mass was spread in a sheet of living film, almost invisible except as a sheen on the flat ground. In space, this sunflower was formed by spinning slowly and letting centrigugal force form the large parabolic organ. Here it lay inert on the ground, pulled out by mechanical devices at the comers of the square. Symbs did not have the musculature to do it themselves.

     No part of their stay on Janus made them yearn for the Rings as much as the kitchen. Barnum reclined in the middle of an empty square and let the mechanical claws fit themselves to Bailey’s outer tegument. They began to pull, slowly, and Bailey was stretched.

     In the Ring they were never more than ten kilometers from the Upper Half. They could drift up there and deploy the sunflower, dream away a few hours, then use the light pressure to push them back into the shaded parts of the Ring. It was nice; it was not exactly sleep, not exactly anything in human experience. It was plant consciousness, a dreamless, simple awareness of the universe, unemcumbered with thought processes.

     Barnum grumbled now as the sunflower was spread on the ground around them. Though the energyintake phase of their existence was not sleep, several days of trying to accomplish it in a gravity well left Barnum with symptoms very like lack of sleep. They were both getting irritable. They were eager to return to weightlessness.

     He felt the pleasant lethargy creep over him. Beneath him, Bailey was extending powerful rootlets into the naked rock, using acid compounds to eat into it and obtain the small amounts of replacement mass the Pair needed.

From GOTTA SING, GOTTA DANCE by John Varley (1976)

Example Suits

These are a few real-world historical prototype space suits that were immediately copied by the science fiction artists at the time.

Harry Ross Lunar Space-Suit for the British Interplanetary Society (1949)

There are a few details here.

B. F. Goodrich XH-5 full-(body) pressure-suit aka "Tomato worm suit" (1940-1943)

Designed by Russell Colley of B. F. Goodrich. It was prominently featured in the July 1947 issue of MECHANIX ILLUSTRATED, in an article by Willy Ley, but it appeared in other magazines as well.

Goodrich engineer Russell Colley was trying design a suit that would bend at the elbow and knee against an internal pressure of 32 kiloPascals. His breakthrough insight came when he saw a Tomato Hornworm caterpillar. Blasted thing could bend 90 degrees, but obviously its internal pressure did not change (i.e., it didn't swell up anywhere). From this observation Colley invented constant-volume joints. Which is why these were called Tomato Worm Suits, and why the joints look like the Michelin Man.

B. F. Goodrich Inflatable Protective Suit for High Altitude Flight (1953)

This was not a space suit so much as a high-altitude aircraft pilot pressure suit. But for science fiction artist it was close enough. Much of the details of the real suit are available in patent 2,954,562.

Wernher von Braun spacesuit design from First Men to the Moon (1959)

This popularized the infamous tentacle gloves, which science fiction artist were quick to copy.

Spacesuits and Ship Combat

The crew of a combat spacecraft in battle probably will not wear a soft, hard-shell, or semi-rigid suit during battle. This is for the same reasons that the crew of a military submarine do not wear SCUBA gear in battle even though they too are in a craft surrounded by countless miles of unbreathable stuff while being shot at. It gets in the way.

But they might wear a partial-(body) pressure suit or a skintight pressure suit.

Or a skintight + partial-(body) hybrid pressure-suit. This might be so unencumbered that it could be used as everday wear. Then if the habitat module loses pressure all you'd need is an oxygen mask and earplugs to survive for a few hours.

Or then again, I may not know what the heck I am talking about:


CHRIS (ROBOTBEAT): One of the best things about The Expanse is that everyone who can dons spacesuits when they’re in a space battle. Why the heck would you not do that in Star Wars or Star Trek?

WINCHELL CHUNG: Well, there is the Navy submarine analogy. Combat submarines are surrounded by an unbreathable medium, just like combat spacecraft. But in a combat situation, the entire submarine crew does not put on scuba gear. Not an exact analogy, but something to think about.

CHRIS (ROBOTBEAT): Submarines are surrounded by a more deadly medium which requires even heavier hulls. Get sliced in half by a leak at depth.. also, you can just hold your breath and swim in a submarine.

Zoe Samuel: Scuba gear is incredibly bulky, it's hard to fit down the hallways on a submarine in it and do your job. And fighter pilots effectively DO put on the gear because they can still work wearing it, and it does help them survive in emergencies.

JAROSLAW BARANOWSKI: Depending on depth, scuba gear with air will be useles. It's all about partial pressures of gasses you breath. No such problem in space, nothing is crushing you or your gear. So it's very different having to face max 1 ATM in spaceship Vs many ATM pressure in a submarine.

CHRIS (ROBOTBEAT): Right, and pressure could be reduced further in the spacecraft, ie to 0.7, 0.5, or even 0.2 atm for such dangerous situations.

HENRY COBB: Difference is that opening a hole to the outside doesn't diesel a spacecraft crew like roast subbies. (Imagine if submarines could only dive to ten meters and you'd have the same sudden pressure change.) Quick poll for the SciTwits: Will future military spacecraft go into battle pressurized to sea level rather than say Denver?

JAROSLAW BARANOWSKI: But if everyone is suited up, you might go all the way and remove all atmo, to prevent fires. Keeping less than 1 ATM would only make sense if you have gear inside that can't tolerate vacuum; would make more sense to replace normal air with non-reactive gas then.

CHRIS (ROBOTBEAT): Disagree. Spacesuits can malfunction, and having pressure makes movement vastly easier. And heat dissipation and everything.

ASTROGRAPHER: The point about easier movement is huge. Even the best, most modern space suits are a bear to work in. The gloves are particularly god-awful. People lose fingernails. The safety suits worn in the Shuttle and capsules are not intended as space suits, merely emergency stop-gaps.

TIKTAALIK DREAMING: But you could have them set up to only seal and inflate of they detect a pressure drop. Hell, even if you had to attach the gloves and helmet yourself, if you were presuited it would save heaps of time.

TIKTAALIK DREAMING: I do like that they check each other's suits in a nod to realism, but like all space fiction they skip over the hours required to get into one. With people living in space, we'd need to get better suits. But space breeds caution.

CHRIS (ROBOTBEAT): Yeah, a properly designed suit doesn’t necessarily need to take hours to don.

JAROSLAW BARANOWSKI: Wouldn't a mechanical counterpressure suit solve the mobility problem while still allowing to keep ship at 0 ATM? I thought there's active research going into those things.

SCOTT MANLEY: They’ve had mechanical counter pressure suits since the 50’s the problem is they’re not comfortable for long duration.

ASTROGRAPHER: Those gloves basically use the principals of mechanical counter-pressure and they’re pretty awful. I’m interested in seeing where research by people like Dava Newman is getting us, but I don’t think the SOTA is there yet, and there may be fundamental limitations I don’t know.

TRENT WADDINGTON: There's been a lot of work since then Scott.

TIKTAALIK DREAMING: And they're still not in use. Given, they may at some stage replace the hominoid balloon, but we can't get them better than those yet.

From a thread on Twitter (2019)

So, space folks, a question has been asked of me regarding that old trope of having everyone fully suited up and dumping the air when your space warships go to general quarters (GQ).

Now, I typically opine (after scribbling some numbers) that there's no point at all to the latter and very little to the former.

On the former point, in the unlikely circumstance that you are tapped gently enough by a munition to just hole your compartment, decompression will generally be slow enough that you have plenty of time to leave the compartment and/or fully don your suit. If, on the other hand, you're fully struck by a munition moving at typical space-intercept velocities, the energies involved are such that it won't matter a damn whether the Charred and Splattered Red Paste Formerly Known As You was suited up or not. And the tiny gap in between these two scenarios is nowhere near wide enough to make it worth giving up the advantages of a shirt-sleeve environment.

On the latter point, the reasons I usually see given for dumping the air include avoiding explosive decompression (about which I think there's no reason to care for the same reasons as above), that it prevents fires, and shockwaves. far as fires go, the first thing that occurs to me is that most of the particularly dangerous things that might burn on a spacecraft are things that have no business being inside the pressure hull in the first place. The second one is that if you're talking about fire caused by, well, incoming fire, then much of the time you're talking about things in the compartment-wrecking open-to-space scenario anyway, in which case the decompression will happen anyway help from you. And the third one is that if you're only dumping the air at GQ, then you need a perfectly functional suite of fire-suppression systems for the rest of the time anyway, so let them do their job.

As for shockwaves — well, again, I would expect that, given the energies involved, whatever damping or transmitting effects the air might have are going to end up lost in the rounding. (High-energy penetrating strikes might include flashover problems from KE ending up in the air, but given all the other things that will kill you in high-energy penetrating strikes, those aren't going to make you any more dead.)

Going Outside

Suiting Up

I had an awful time getting into it — dressing in an upper berth is a cinch by comparison. The photographer said, "Just a minute, kid. I've seen 'em do it at Wright Field. Mind some advice?"

"Uh? No. I mean, yes, tell me."

"You slide in like an (Inuit) climbing into a kayak. Then wiggle your right arm in—"

It was fairly easy that way, opening front gaskets wide and sitting down in it, though I almost dislocated a shoulder. There were straps to adjust for size but we didn't bother; he stuffed me into it, zippered the gaskets, helped me to my feet and shut the helmet.

. . .

But I didn't get tired of it; a space suit is a marvelous piece of machinery — a little space station with everything miniaturized. Mine was a chrome-plated helmet and shoulder yoke which merged into a body of silicone, asbestos, and glass-fibre cloth. This hide was stiff except at the joints. They were the same rugged material but were "constant volume" — when you bent a knee a bellows arrangement increased the volume over the knee cap as much as the space back of the knee was squeezed. Without this a man wouldn't be able to move; the pressure inside, which can add up to several tons, would hold him rigid as a statue. These volume compensators were covered with dural armor; even the finger joints had little dural plates over the knuckles.

It had a heavy glass-fibre belt with clips for tools, and there were the straps to adjust for height and weight. There was a back pack, now empty, for air bottles, and zippered pockets inside and out, for batteries and such.

The helmet swung back, taking a bib out of the yoke with it, and the front opened with two gasketed zippers; this left a door you could wiggle into. With helmet clamped and zippers closed it was impossible to open the suit with pressure inside.

Switches were mounted on the shoulder yoke and on the helmet; the helmet was monstrous. It contained a drinking tank, pill dispensers six on each side, a chin plate on the right to switch radio from "receive" to "send," another on the left to increase or decrease flow of air, an automatic polarizer for the face lens, microphone and earphones, space for radio circuits in a bulge back of the head, and an instrument board arched over the head. The instrument dials read backwards because they were reflected in an inside mirror in front of the wearer's forehead at an effective fourteen inches from the eyes.

Above the lens or window there were twin headlights. On top were two antennas, a spike for broadcast and a horn that squirted microwaves like a gun-you aimed it by facing the receiving station. The horn antenna was armored except for its open end.

This sounds as crowded as a lady's purse but everything was beautifully compact; your head didn't touch anything when you looked out the lens. But you could tip your head back and see reflected instruments, or tilt it down and turn it to work chin controls, or simply turn your neck for water nipple or pills. In all remaining space sponge-rubber padding kept you from banging your head no matter what. My suit was like a fine car, its helmet like a Swiss watch. But its air bottles were missing; so was radio gear except for built-in antennas; radar beacon and emergency radar target were gone, pockets inside and out were empty, and there were no tools on the belt. The manual told what it ought to have — it was like a stripped car.

Carry steel bottles on your back; they hold "air" (oxygen and helium) at a hundred and fifty atmospheres, over 2000 pounds per square inch; you draw from them through a reduction valve down to 150 p.s.i. and through still another reduction valve, a "demand" type which keeps pressure in your helmet at three to five pounds per square inch — two pounds of it oxygen. Put a silicone-rubber collar around your neck and put tiny holes in it, so that the pressure in the body of your suit is less, the air movement still faster; then evaporation and cooling will be increased while the effort of bending is decreased. Add exhaust valves, one at each wrist and ankle — these have to pass water as well as gas because you may be ankle deep in sweat.

The bottles are big and clumsy, weighing around sixty pounds apiece, and each holds only about five mass pounds of air even at that enormous pressure; instead of a month's supply you will have only a few hours — my suit was rated at eight hours for the bottles it used to have.

. . .

To make darn sure that you're getting enough (your nose can't tell) you clip a little photoelectric cell to your ear and let it see the color of your blood; the redness of the blood measures the oxygen it carries. Hook this to a galvanometer. If its needle gets into the danger zone, start saying your prayers. (ed. note: in Heinlein's other novels, instead of a galvanometer they use an "anoxia warning light")

. . .

Air sighed softly into the helmet, its flow through the demand valve regulated by the rise and fall of my chest — I could reset it to speed up or slow down by the chin control.

. . .

I didn't bother with a radar target or beacon; the first is childishly simple, the second is fiendishly expensive. But I did want radio for the space-operations band of the spectrum — the antennas suited only those wavelengths.

. . .

The only thing that complicated the rest of the electrical gear was that everything had to be either "fail-safe" or "no-fail"; a man in a space suit can't pull into the next garage if something goes wrong — the stuff has to keep on working or he becomes a vital statistic. That was why the helmet had twin headlights; the second cut in if the first failed — even the peanut lights for the dials over my head were twins. I didn't take short cuts; every duplicate circuit I kept duplicate and tested to make sure that automatic changeover always worked.

Mr. Charton insisted on filling the manual's list on those items a drugstore stocks — maltose and dextrose and amino tablets, vitamins, dexedrine (yikes, back in 1958 the drugstore would give an 18 year old boy amphetamines), dramamine, aspirin, antibiotics, antihistamines, codeine, almost any pill a man can take to help him past a hump that might kill him.

. . .

I made it a dress rehearsal — water in the drinking tank, pill dispensers loaded, first-aid kit inside, vacuum-proof duplicate (I hoped it was vacuum-proof) in an outside pocket. All tools on belt, all lanyards tied so that tools wouldn't float away in free fall.

. . .

I ran into a snag. The spare bottles I had filched from those ghouls had screw-thread fittings like mine — but Peewee's bottles had bayonet-and-snap joints. Okay, I guess, for tourists, chaperoned and nursed and who might get panicky while bottles were changed unless it was done fast — but not so good for serious work.

. . .

"Mind your pressure. Kip. You're swelling up too fast." I kicked the chin valve while watching the gauge — and kicking myself for letting a little girl catch me in a greenhorn trick. But she had used a space suit before, while I had merely pretended to.

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)

(ed note: this is a bit dated since it was written in 1939, but still surprisingly good)

"This is a standard service type, general issue, Mark IV, Modification 2." He grasped the suit by the shoulders and shook it out so that it hung like a suit of long winter underwear with the helmet lolling helplessly between the shoulders of the garment. "It's self-sustaining for eight hours, having an oxygen supply for that period. It also has a nitrogen trim tank and a carbon dioxide water-vapor cartridge filter."

He droned on, repeating practically verbatim the description and instructions given in training regulations. McCoy knew these suits like his tongue knew the roof of his mouth; the knowledge had meant his life on more than one occasion.

"The suit is woven from glass fibre laminated with nonvolatile asbesto-cellutite. The resulting fabric is flexible, very durable; and will turn all rays normal to solar space outside the orbit of Mercury. It is worn over your regular clothing, but notice the wire-braced accordion pleats at the major joints. They are so designed as to keep the internal volume of the suit nearly constant when the arms or legs are bent. Otherwise the gas pressure inside would tend to keep the suit blown up in an erect position and movement while wearing the suit would be very fatiguing.

"The helmet is moulded from a transparent silicone, leaded and polarized against too great ray penetration. It may be equipped with external visors of any needed type. Orders are to wear not less than a number-two amber on this body. In addition, a lead plate covers the cranium and extends on down the back of the suit, completely covering the spinal column.

"The suit is equipped with two-way telephony. If your radio quits, as these have a habit of doing, you can talk by putting your helmets in contact. Any questions?"

"How do you eat and drink during the eight hours?"

"You don't stay in 'em any eight hours. You can carry sugar balls in a gadget in the helmet, but you boys will always eat at the base. As for water, there's a nipple in the helmet near your mouth which you can reach by turning your head to the left. It's hooked to a built-in canteen. But don't drink any more water when you're wearing a suit than you have to. These suits ain't got any plumbing."

Suits were passed out to each lad, and McCoy illustrated how to don one. A suit was spread supine on the deck, the front zipper that stretched from neck to crotch was spread wide and one sat down inside this opening, whereupon the lower part was drawn on like long stockings. Then a wiggle into each sleeve and the heavy flexible gauntlets were smoothed and patted into place. Finally an awkward backward stretch of the neck with shoulders hunched enabled the helmet to be placed over the head.

Libby followed the motions of McCoy and stood up in his suit. He examined the zipper which controlled the suit's only opening. It was backed by two soft gaskets which would be pressed together by the zipper and sealed by internal air pressure. Inside the helmet a composition mouthpiece for exhalation led to the filter.

From MISFIT by Robert Heinlein (1939)

(ed note: The people are using powered-armor spacesuits on planets where the temperature hovers around -270°C, 8 K)

"Now, you didn't get much in-suit training Earthside. We didn't want you to get used to using the thing in a friendly environment. The fighting suit is the deadliest personal weapon ever built, and with no weapon is it easier for the user to kill himself through carelessness. Turn around, Sergeant.

"Case in point." He tapped a large square protuberance between the shoulders. "Exhaust fins. As you know, the suit tries to keep you at a comfortable temperature no matter what the weather's like outside. The material of the suit is as near to a perfect insulator as we could get, consistent with mechanical demands. Therefore, these fins get hot especially hot, compared to darkside temperatures—as they bleed off the body's heat.

"All you have to do is lean up against a boulder of frozen gas; there's lots of it around. The gas will sublime off faster than it can escape from the fins; in escaping, it will push against the surrounding ice, and fracture it … and in about one-hundredth of a second, you have the equivalent of a hand grenade going off right below your neck. You'll never feel a thing.

"Variations on this theme have killed eleven people in the past two months. And they were just building a bunch of huts. (imagine how dangerous it will be when the enemy is shooting at you)

"Now everybody pay close attention. I'm going out to that blue slab of ice"—it was a big one, about twenty meters away—"and show you something that you'd better know if you want to stay alive."

He walked out in a dozen confident steps. "First I have to heat up a rock—filters down." I squeezed the stud under my armpit and the filter slid into place over my image converter. The captain pointed his finger at a black rock the size of a basketball, and gave it a short burst. The glare rolled a long shadow of the captain over us and beyond. The rock shattered into a pile of hazy splinters.

"It doesn't take long for these to cool down." He stopped and picked up a piece. "This one is probably twenty or twenty-five degrees (Kelvin, -248°C). Watch." He tossed the "warm" rock onto the ice slab. It skittered around in a crazy pattern and shot off the side. He tossed another one, and it did the same.

"As you know, you are not quite perfectly insulated. These rocks are about the temperature of the soles of your boots. If you try to stand on a slab of hydrogen, the same thing will happen to you. Except that the rock is already dead.

"The reason for this behavior is that the rock makes a slick interface with the ice—a little puddle of liquid hydrogen—and rides a few molecules above the liquid on a cushion of hydrogen vapor. This makes the rock or you a frictionless bearing as far as the ice is concerned, and you can't stand up without any friction under your boots.

"After you have lived in your suit for a month or so you should be able to survive falling down, but right now you just don't know enough. Watch."

The captain flexed and hopped up onto the slab. His feet shot out from under him and he twisted around in midair, landing on hands and knees. He slipped off and stood on the ground.

"The idea is to keep your exhaust fins from making contact with the frozen gas. Compared to the ice they are as hot as a blast furnace, and contact with any weight behind it will result in an explosion."

From THE FOREVER WAR by Joe Haldeman (1975)

Besides the usual cargo lock we had three Kwikloks. A Kwiklok is an Iron Maiden without spikes; it fits a man in a suit, leaving just a few pints of air to scavenge, and cycles automatically. A big time saver in changing shifts. I passed through the middle-sized one; Tiny, of course, used the big one. Without hesitation the new man pulled himself into the small one.

From DELILAH AND THE SPACE-RIGGER by Robert Heinlein (1949)


Current NASA space suits take about 45 minutes to put on, though that does include the time it takes to don the water-cooled undergarments. But not including 110 minutes for the Slow Motion Hokey Pokey

The Russian space program was working on a space suit called the Orlan (Орлан "sea eagle") that could be donned in five minutes flat. The backpack PLSS swung open like a door allowing the astronaut to step inside (it still take a while to put on the water cooled long-johns).

In 1980 the Russian space program realized that the rear entry door space suit could be used as a low mass airlock. Instead of a huge room with two air-tight doors, all you need is a hole in the hull the size of the PLSS with an airtight inner hatch cover. This is called a "Suitport".

The suit is outside of the spacecraft or whatever, only the PLSS is inside. The cosmonaut slips into the suit, a helper shuts the PLSS door and covers it with the airtight inner hatch cover. The cosmonaut is outside of the habitat module and can conduct EVA activities. The Russians patented the idea in 1980, and NASA patented it in 1987. In some designs the helper is replaced by an external hand level that the EVA astronaut flips to open/close the suit lock.

As an additional advantage, this system avoids enviromental contamination. Astronauts will not track into the lunar base any lung-destroying lunar dust. By the same token, Terran bacteria will not be allowed to get on the surface of a Mars planetary suit, and thereby contaminate the Martian environment. The only part of the suit that can do any contamination is the PLSS, the rest of the suit never enters the hab module.

There is still the problem of the pressure difference habitat module and the space suit. But a pre-breathing room is a lot less of a mass penalty than a full airlock.

The ESA Aurora CDF Mars mission looked into using suitports on their Mars lander:


A suitport or suitlock is an alternative technology to an airlock, designed for use in hazardous environments and in human spaceflight, especially planetary surface exploration. Suitports present advantages over traditional airlocks in terms of mass, volume, and ability to mitigate contamination by—and of—the local environment.


In a suitport system, a rear-entry space suit is attached and sealed against the outside of a spacecraft, space habitat, or pressurized rover, facing outward. To begin an extra-vehicular activity (EVA), an astronaut in shirt-sleeves first enters the suit feet-first from inside the pressurized environment, and closes and seals the space suit backpack and the vehicle's hatch (which seals to the backpack for dust containment). The astronaut then unseals and separates the suit from the vehicle, and is ready to perform an EVA.

To re-enter the vehicle, the astronaut backs up to the suitport and seals the suit to the vehicle, before opening the hatch and backpack and transferring back into the vehicle. If the vehicle and suit do not operate at the same pressure, it will be necessary to equalize the two pressures before the hatch can be opened.

Advantages and disadvantages


Suitports carry three major advantages over traditional airlocks. First, the mass and volume required for a suitport is significantly less than that required for an airlock. Launch mass is at a premium in modern chemical rocket-powered launch vehicles, at an estimated cost of US$60,000 per kilogram delivered to the lunar surface.

Secondly, suitports can eliminate or minimize the problem of dust migration. During the Apollo program, it was discovered that the lunar soil is electrically charged, and adheres readily to any surface with which it comes into contact, a problem magnified by the sharp, barb-like shapes of the dust particles. Lunar dust may be harmful in several ways:

  • The abrasive nature of the dust particles may rub and wear down surfaces through friction.
  • The dust may damage coatings used on gaskets, optical lenses, solar panels, windows, and wiring.
  • The dust may cause damage to an astronaut's lungs as well as nervous and cardiovascular systems, leading to conditions such as pneumoconiosis.

During the Apollo missions, the astronauts donned their space suits inside the Apollo Lunar Module cabin, which was then depressurized to allow them to exit the vehicle. Upon the end of EVA, the astronauts would re-enter the cabin in their suits, bringing with them a great deal of dust which had adhered to the suits. Several astronauts reported a "gunpowder" smell and respiratory and/or eye irritation upon opening their helmets and being exposed to the dust.

When the suit is attached to the vehicle, any dust which may have adhered to the backpack of the suit is sealed between the outside of the backpack and the vehicle-side hatch. Any dust on the suit that is not on the backpack remains sealed outside the vehicle. Likewise, the suitport prevents contamination of the external environment by microbes carried by the astronaut.

Additionally, the suitports significantly reduce the ingress and egress time, and virtually remove the need of pumpdown of the airlock, which normally is either associated with air loss, or requires heavy and complex pumping machinery as the only space that needs to be pressurized is the area between the vehicle hatch and the life-support backpack, and even that only in case of need for repairs, decontamination and refitting of the suit.


Disadvantages of suitports include the additional mass of the interface on the rear of the space suit which may be more than 4.5 kg, and increased mechanical complexity, potentially reducing the overall reliability of the EVA system. According to NASA's Exploration Systems Mission Directorate, disadvantages of suitports also include:

  • A lower Technology Readiness Level (TRL) than airlocks
  • Greater difficulty for incapacitated crewmembers to ingress
  • Possible requirement for suit donning at 8 pounds per square inch (0.54 atm) with relaxed man-loads
  • Likely requirement for some back-mounted Primary Life Support System components, introducing challenges for achieving an optimal center of mass.

Development and use

The first EVA rear entry space suit was developed at NPP Zvezda in 1962. The suitport concept was suggested for use in the Soviet manned Moon program. A patent for a suitport was first filed in 1980 in the Soviet Union, by Isaak Abramov of Zvezda and Yuri Nazarov of CKBM.

A US patent for a suitport was first filed in 1987 by Marc M. Cohen of NASA's Ames Research Center. Further patents were filed in 1996 by Philip Culbertson Jr., and in 2003 by Joerg Boettcher, Stephen Ransom, and Frank Steinsiek.

As of 1995, suitports have found a practical, terrestrial application as part of a NASA Ames hazardous materials vehicle, where the use of the suitport eliminates the need to decontaminate the hazmat suit before doffing. A suitport prototype built by Brand Griffin has been used in a simulated lunar gravity test on board NASA Johnson's C-135 aircraft.

Suitports may find use as part of future NASA projects aimed at achieving a return to the Moon and manned exploration of Mars. NASA's conceptual Space Exploration Vehicle has two suitports on the back of the craft.

Testing has been taking place in combination with the Z-1 prototype spacesuit inside NASA's human-rated thermal vacuum chamber B at the Johnson Space Center. Early unmanned tests of the suitport were conducted in June 2012. The first manned tests of the suitport occurred on 16 and 18 July 2012; during these manned tests the spacesuit was kept at a pressure of 14.7 psi (1 atm) with the chamber pressure at approximately 6.5 psi (0.44 atm), equivalent to an altitude of 21,000 feet (6,400 m). Future manned tests were planned for September and August 2012, where NASA planned to keep the spacesuit at a pressure of 8 psi (0.5 atm) and the vacuum chamber at roughly 0 psi (0 atm). Suitports may eventually be tested on the International Space Station.

From the Wikipedia entry for SUITPORT

Safety Check

First Jamieson, then Wheeler, chanted the alphabetic mnemonic - "A is for air-lines, B is for batteries, C is for couplings, D is for D.F. loop ..." which sounds so childish the first time one hears it, but which so quickly becomes part of the routine of lunar life - and is something nobody ever jokes about.

From EARTHLIGHT by Sir Arthur C. Clarke. 1955.

And in Clarke's "The Haunted Spacesuit" aka "Who's There?" they chant "FORB" for Fuel, Oxygen, Radio, Batteries.

[Steve and Nadia] donned the heavily-insulated, heated suits, and Stevens snapped into their sockets the locking plugs of the drag line.

"Hear me?" he asked. "Sound-disks all x?"

"All x."

"On the radio-all x?"

"All x."

"I tested your tanks and heaters-they're all x. But you'll have to test..."

"I know the ritual by heart, Steve. It's been in every show in the country for the last year, but I didn't know you had to go through it every time you went out-of-doors! Valves, number one all x, two all x, three all x..."

"Quit it!" he snapped. "You aren't testing those valves! That check-up is no joke, guy (Steve is using "guy" sarcastically, Nadia is quite female). These suits are complicated affairs, and some parts are apt to get out of order. You see, a thing to give you fresh air at normal pressure and to keep you warm in absolute space can't be either simple or foolproof. They've worked on them for years, but they're pretty crude yet. They're tricky, and if one goes sour on you out in space it's just too bad — you're lucky to get back alive. A lot of men are out there somewhere yet because of sloppy check-ups."

" 'Scuse it, please — I'll be good," and the careful checking and testing of every vital part of the space-suits went on.

From SPACEHOUNDS OF IPC by E.E. "Doc" Smith, 1931.

The instructor ordered his group to "Suit up!" without preliminary, as it was assumed that they had studied the instruction spool.

The last of the ship's spin had been removed some days before. Matt curled himself into a ball, floating free, and spread open the front of his suit. It was an unhandy process; he found shortly that he was trying to get both legs down one leg of the suit. He backed out and tried again. This time the big fishbowl flopped forward into the opening.

Most of the section were already in their suits. The instructor swam over to Matt and looked at him sharply. "You've passed your free-fall basic?"

"Yes," Matt answered miserably.

"It's hard to believe. You handle yourself like a turtle on its back. Here." The instructor helped Matt to tuck in, much as if he were dressing a baby in a snow suit. Matt blushed.

The instructor ran through the check-off list — tank pressure, suit pressure, rocket fuel charge, suit oxygen, blood oxygen (measured by a photoelectric gadget clipped to the earlobe) and finally each suit's walky-talky unit. Then he herded them into the airlock.

From SPACE CADET by Robert Heinlein (1948)

In spite of the fail-safe design of the P-suits— so loss of pressure in one part of the suit won't result in a total loss of suit pressure—we lost a rigger yesterday for a stupid reason.

Riggers working in P-suits are required to use the Buddy System—checking each other's gear before cycling to vacuum. But this crew was in a hurry to get on the job. So the buddy didn't check both of the helmet pressurizing lines where the fittings go into the helmet. From what Pratt determined by studying the P-suit later, neither line was inserted in the fitting past the detent. I've got to admit, it's difficult to tell when you've twisted the fitting past the detent, especially if you're already wearing P-suit gloves.

Out in vacuum, the guy snagged one of the lines and pulled it out of the helmet fitting. The check valve closed when the line left the fitting, just as it's supposed to do. But when he heard the line come out of the fitting, he turned, caught the other line on the same beam element, and pulled the second line far enough out of the fitting so it blew most of his back-pack oxygen supply out into space . . . and at the same time failed to come out of the fitting far enough to activate the check valve. He lost helmet pressure in a few seconds. By the time his buddy got to him, he died from what Fred termed "traumatic abaryia," or rapid and terminal loss of pressurization.

Another case was perhaps worse from our point of view because, although the man was alive when we got him, he was too far gone to save. Writers often talk about the "primordial cold of outer space." But we lost this man to hyperpyrexia—overheating.

P-suit backpacks are designed to get rid of the metabolic heat generated by the individual, plus the environmental heat load from outside. There's a limit to the backpack's capability. Everybody's trained to recognize the symptoms of potential overload—a rise in P-suit temperature, hyperventilation, headache, et cetera. When it starts to happen, you slow down, rest, relax— or you're dead very quickly. This poor guy never had a chance, and it was a genuine industrial accident thai finished him.

While a photovoltaic power module's brought up from LEO Base, where it's assembled, it converts sunlight to electricity, which is used to power the electric thrusters which propel it to GEO Base. The structure isn't metal; it's a carbon-reinforced composite plastic.

The riggers had docked the new module to the main array, and Lucky's crew moved in to make the electrical switchover. Supposedly, it's impossible to create an electric arc in a vacuum, but GEO Base is surrounded by a halo of escaped life-support-system gases, outgas-sing products from materials, and other things that make the vacuum less than perfect. This is a construction site, and I've never seen a clean construction site anywhere.

During one of the switchover sequences, part of an insulator failed and an arc jumped across the rest of the insulator to the structure. It vaporized the carbon-composite plastic, which in turn vapor-deposited on everything within fifty feet, including the P-suit of the man who was nearby. It blackened his P-suit within a fraction of a second. He was in full sunlight at the time. Within ten seconds his suit and backpack were too hot for the backpack system to handle. He practically fried in less than thirty seconds.

"Med Unit, Central!" the intercom rasped. "Accident in vacuum! Reported P-suit fire! Location Array Subassembly Module One Zero Seven. Repeat: One Zero Seven!"

One of the P-suited individuals was obviously unconscious. Tom surmised this from the limp, rag-doll posture and random small movements of the limbs of the P-suit. He looked at the faceplate and discovered that the inside surface was covered with a brownish-black deposit, The injured man was no longer being supported by his own backpack. It had been disconnected, and he had been buddy-coupled to another individual's pack.

"What happened?" Tom asked.

"Fire in the backpack," somebody announced on the radio.

"Jed hollered that's what happened before he choked," another voice cut in. "Pete got him hooked up buddy-style (cross-connect) in about twenty seconds."

It didn't take more than thirty seconds to repressurize the Pumpkin (ambulance). Then Tom opened the faceplate of the injured man's P-suit helmet. The man had had a beard that had been singed off. There were first- and second-degree burns on his face. The most severe burns were in the vicinity of the oxygen inlet couplings from the backpack to the helmet. Tom had no way of knowing the nature or extent of possible burns in the lungs or airways.

It didn't take long to determine the source of the fire. Each backpack contains two high-pressure-oxygen storage bottles. A pressure switch valves a full bottle into the system when it senses the on-line bottle's pressure has dropped below a preset limit. The high-pressure oxygen then flows through a regulator that drops the pressure to about five psi absolute. The plastic O-ring that seals the upstream side of the regulator may have had a trace of contamination on it; the culprit seems to be aluminum shaved off the fitting when a maintenance tech over-tightened it. When the pressure sensor switched tanks, a shock wave of high-pressure oxygen hit the upstream side of the regulator fitting and was heated by shock compression. This action ignited whatever was on the O-ring. The aluminum of the regulator body then began to burn in the hot, oxygen-rich atmosphere, and, in turn, sent an oxygen-rich flame right down the breathing pressure lines to the interior of Hobart's helmet.

A fifty-cent O-ring and an uncalibrated torque wrench killed a man. It could also call a halt to a multibillion-dollar project.

Pratt says it's a simple fix. He's got his maintenance techs replacing O-rings and installing a diffuser upstream of the regulator as each backpack comes in from vacuum for refurbishment at the end of each shift.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

These days, Joe Nowetner is an operations manager at UTC Aerospace Systems, the contractor responsible for NASA's fleet of spacesuits. Early in his career, Joe worked as an electrical technician at the Johnson Space Center (JSC) supporting the testing regimen of a new spacesuit design, the EMU (Extravehicular Mobility Unit). One particular test served as a startling reminder that exploring space is a dangerous business…even for those who never leave the ground. Joe has never forgotten the lessons he learned that day. Neither has NASA.

The EMU Fire

The EMU design would persevere to become the spacesuit worn by spacewalking astronauts throughout the Space Shuttle Program and even today on the International Space Station. In the nearly 40-year history of the suit, truly scary moments have been so infrequent that they are still referenced in generic terms, with no distinction needed…i.e. "the water leak", "the chamber incident", "the bellows failure". In that lingo, the events of April 18, 1980 are summarized as "the EMU fire".

At that time, the space shuttle was still ramping up for its inaugural flight and the EMU was an unproven system. Nowetner was part of a JSC team tasked to execute functional tests on an EMU unit. This task was a critical step in preparation for the first manned test of the suit, an event where space-like conditions would be simulated in a large vacuum chamber.

Although the EMU was unmanned for the April test, the suit's life support system was exercised. Ironically, it was the life support system that caused a flash fire which burned two technicians (one severely), destroyed the EMU, and reawakened a culture of safety throughout NASA. Here's what happened.

Oxygen Ignited

The EMU life support system consists of a primary oxygen supply at 900psi and a secondary oxygen supply at 6000psi. The fire erupted when a technician executed a planned task to put the EMU in "EVA" mode. This introduced the secondary oxygen supply to a pressure regulator within the suit. The source of the fire was traced to this regulator, but investigators never determined what specifically ignited the oxygen. Three probable causes were theorized:

  1. Heating of an unintended thin wall within the regulator due to rapid compression

  2. Ignition of an O-ring due to rapid compression

  3. A contaminant particle striking an interior surface of the regulator at high velocity

While the cause of the fire remains uncertain, its destructive effects were apparent. Fueled by pure high-pressure oxygen, the onset of the fire was immediate and intense. The aluminum block that comprised the regulator was vaporized in less than one second. Other aluminum components burned in the oxygen-rich environment. Fabric components of the suit ignited and remained aflame until responders utilized carbon dioxide fire extinguishers. Total hardware damage was estimated to be about two million dollars.

The most seriously injured technician was hospitalized with first and second degree burns over 30% of his body. Another technician suffered burns to his hands but did not require hospitalization. The failed regulator had 19 previous high-pressure cycles without incident. If the regulator had held out for a few more cycles and failed during the manned event, the expected consequences would have been much more dire.

Sorting It Out

In the weeks following the fire, a team of engineers attempted to find out what went wrong. Using regulators from the same batch as the burned unit, investigators made more than 2000 attempts to recreate the blaze—all unsuccessful. Even without a smoking gun, the team found numerous areas to be concerned about and recommended a list of engineering and procedural changes to the EMU.

Most of the suggested changes were geared towards mitigating the risks presented by the three suspected ignition sources. The aluminum regulator was changed to Monel (a nickel/copper alloy that resists burning in pure oxygen). Machining and inspection methods used to manufacture the regulator were revised to prevent and identify errors that would create thin internal walls. O-rings were replaced with more ignition-resistant materials. Passageways in the regulator were redesigned to reduce the probability of trapping contaminants within the system. The list goes on.

In addition to the technical analysis of the regulator failure, investigators scrutinized other disconcerting aspects of the fire. For instance, the test took place in a room with just a single exit door. Of the seven occupants in the room when the fire erupted, only Nowetner and one other fled through the door. Those remaining who were able to flee moved deeper into the room, where they would have been trapped if the fire had spread. Not only were escape options limited, but none of the participants had been briefed on how to react if a fire occurred. Although Joe had found safety outside the room, he returned to help those still inside.

Protective equipment was another concern. Everyone in the room was wearing safety glasses, as dictated by test protocol. It is believed that this precaution helped save the eyesight of the severely burned technician. Unfortunately, they were also wearing nylon smocks. These have a tendency to melt into skin during a fire, making a bad situation worse. Although he escaped uninjured, Nowetner's smock had numerous burn marks from spattered aluminum. The investigation panel suggested switching to more fire resistant fabrics.

Lessons Learned…and Applied

The design changes made to the EMU life support system have thus far prevented similar fires from occurring. Yet, there were many other effects that reached far beyond the EMU community. In identifying the root causes of the incident, NASA determined that future tests could be made safer with a greater focus on identifying potential problems in advance. As a result, NASA formalized the procedures used when executing tests and required that they be reviewed by an independent safety organization to identify hazards.

NASA also levied requirements for every testing or training event to undergo a Test Readiness Review (TRR) and/or Safety Review by a panel of subject matter experts. These milestone events have become an established facet of the NASA culture. It's easy to look from the outside (or even the inside) and think that the overhead of maintaining such rigorous review standards makes the agency a slow-moving morass of analysis. There is certainly some truth to that. Yet, with priceless custom hardware and human lives often at risk, the cost of repeating mistakes seems harder to bear.

Even routine events are subject to these review requirements. I can't begin to estimate the number of TRRs that I attended during my time at JSC--most of them held in the same room with the same people discussing the same topics. Yet, if I ever felt that the process was extravagant, I needed only glance at a photo on the wall to remind me why such diligence is necessary. It was a photo of the burned EMU.

I do not intend to suggest that NASA lacked a safety conscience prior to the EMU fire. Nor would it be accurate to say that the fire was the only catalyst for change. Subsequent events such as the Challenger and Columbia disasters also had deep and lasting effects to the agency's views on safety. However, I think it would be fair to say that NASA's pre-fire safety culture lacked focus and uniformity. The lessons of the EMU fire played a strong part in introducing those elements.

Teaching a New Generation

Many working at JSC today were not even born when the EMU fire reshaped NASA's approach to safety. Perhaps some who participate in the agency's current safety processes aren't aware of their genesis. Joe likes to show them. He has given numerous presentations to various NASA audiences over the years, explaining how a fire that few people know about provided lessons that NASA will never forget.

My thanks to Joe Nowetner for taking the time to share his story with me.


First things first, and the first thing you need in space is a space suit. Apart from its necessity for working on space projects (building space stations, etc.) it is absolutely vital for examining the outside of your ship in case of damage from meteorites, etc. It may even be necessary to abandon ship, in extreme cases, and in this event your very existence depends upon its efficiency. You see me here in a self-contained, total-vacuum, mark-seven suit. Below you will find listed some of its most important features:

  1. Radio mast of ultra short-wave radio.
  2. Compressed air cylinder of closed-circuit air supply.
  3. Jet on universal mounting and chemical-fuel container.
  4. All joints reinforced. A punctured space suit means death!
  5. Reinforced plastic boots with electro-magnetic soles.
  6. Large universal-vision, anti-cosmic "Plastilight" helmet.
  7. Scaling ring to visor, metal with rubber "hose" lining, inflated from air supply.
  8. Miniature tele-view tray (referred to as the "T" tray).
  9. Control stick to jet (3). Twist grip rotates jet for manœuvring in space.
  10. Hydro-ammonal container and feed line to flame gun.
From Ron Turner's SPACE ACE POP UP BOOK (1953).

Buddy System

While wearing a space suit in vacuum, the iron-clad rule is The Buddy System. There are many mishaps that are trivial if you have a companion but fatal if you don't. Imagine that your suit springs a slow leak on your back just where you can't reach it with a repair patch. Oops.

In cases of emergency, two space suited people can "cross-connect" their oxygen supplies. This is generally done when one of them runs out of breathable gas, the other shares their oxygen until they get to shelter.

ed note: Kip (a college student) and Peewee (a little girl) are wearing spacesuits and are engaged in a forced march across the surface of Luna. Unfortunately the spare oxygen bottles the are carrying have connections incompatible with Peewee's suit. Kip uses surgical tape as an adapter to recharge Peewee's bottle. Peewee has tied the spare bottles to Kip's front. Oh, and Kip named his spacesuit "Oscar")

We were about halfway down the outer slope when Peewee slowed and stopped—sank to the ground and sat still.

I hurried to her. “Peewee!”

“Kip,” she said faintly, “could you go get somebody? Please? You know the way now. I’ll wait here. Please, Kip?”

“Peewee!” I said sharply. “Get up! You’ve got to keep moving.”

“I c-c- can’t!” She began to cry. “I’m so thirsty … and my legs—” She passed out.

“Peewee!” I shook her shoulder. “You can’t quit now! Mother Thing! —you tell her!”

Her eyelids fluttered. “Keep telling her, Mother Thing!” I flopped Peewee over and got to work. Hypoxia hits as fast as a jab on the button. I didn’t need to see her blood-color index to know it read DANGER; the gauges on her bottles told me. The oxygen bottles showed empty, the oxy-helium tank was practically so. I closed her exhaust valves, overrode her chin valve with the outside valve and let what was left in the oxy-helium bottle flow into her suit. When it started to swell I cut back the flow and barely cracked one exhaust valve. Not until then did I close stop valves and remove the empty bottle.

I found myself balked by a ridiculous thing.

Peewee had tied me too well; I couldn’t reach the knot! I could feel it with my left hand but couldn’t get my right hand around; the bottle on my front was in the way—and I couldn’t work the knot loose with one hand.

I made myself stop panicking. My knife—of course, my knife! It was an old scout knife with a loop to hang it from a belt, which was where it was. But the map hooks on Oscar’s belt were large for it and I had had to force it on. I twisted it until the loop broke.

Then I couldn’t get the little blade open. Space-suit gauntlets don’t have thumb nails.

I said to myself: Kip, quit running in circles. This is easy. All you have to do is open a knife—and you’ve got to … because Peewee is suffocating. I looked around for a sliver of rock, anything that could pinch-hit for a thumb nail. Then I checked my belt.

The prospector’s hammer did it, the chisel end of the head was sharp enough to open the blade. I cut the clothesline away.

I was still blocked. I wanted very badly to get at a bottle on my back. When I had thrown away that empty and put the last fresh one on my back, I had started feeding from it and saved the almost half-charge in the other one. I meant to save it for a rainy day and split it with Peewee. Now was the time—she was out of air, I was practically so in one bottle but still had that half-charge in the other—plus an eighth of a charge or less in the bottle that contained straight oxygen (the best I could hope for in equalizing pressures), I had planned to surprise her with a one-quarter charge of oxy-helium, which would last longer and give more cooling. A real knight-errant plan, I thought. I didn’t waste two seconds discarding it.

I couldn’t get that bottle off my back!

Maybe if I hadn’t modified the backpack for nonregulation bottles I could have done it. The manual says: “Reach over your shoulder with the opposite arm, close stop valves at bottle and helmet, disconnect the shackle—” My pack didn’t have shackles; I had substituted straps. But I still don’t think you can reach over your shoulder in a pressurized suit and do anything effective. I think that was written by a man at a desk. Maybe he had seen it done under favorable conditions. Maybe he had done it, but was one of those freaks who can dislocate both shoulders. But I’ll bet a full charge of oxygen that the riggers around Space Station Two did it for each other as Peewee and I had, or went inside and deflated.

If I ever get a chance, I’ll change that. Everything you have to do in a space suit should be arranged to do in front — valves, shackles, everything, even if it is to affect something in back. We aren’t like Wormface, with eyes all around and arms that bend in a dozen places; we’re built to work in front of us — that goes triple in a space suit.

You need a chin window to let you see what you’re doing, too! A thing can look fine on paper and be utterly crumby in the field.

From HAVE SPACE SUIT - WILL TRAVEL by Robert A. Heinlein (1958)

Suit Emergency

A dangerous space suit emergency is if the suit springs a leak. Dimitri SIyde tells me that according to the NASA EMU LSS/SSA Data Book the “free volume” inside a space suit is from 0.04 to 0.06 cubic meters (the gas volume of the anthropometric clearance between the crewmember and the inside of the suit including the PLSS oxygen ventilating circuit). A hole 0.6 cm in diameter has a hole area of 0.28 square centimeters. As long as the suit's air tanks can keep up the loss the pressure won't drop. But once the tanks are empty, the pressure will drop by anoxia levels in a mere 27.9 seconds. Then you get to learn first-hand the many ways that space kills you.

Remember that Skintight suits are immune to this, unless it is your helmet that suffers the breech. If the suit part pops a hole it just gives that part of your skin a bruise.

A critical piece of equipment is some kind of emergency pressure patch. Something the astronaut can stick on to the hole to temporarily halt the pressure leak, or at least long enough to get into a habitat module. This is yet another demonstration of the need for a Buddy System. Not only will a buddy probably be a little more calm than you when applying a patch since it isn't their breathing mix that is escaping into space, but there are some possible suit breech sites that a solo astronaut just cannot reach by themselves.

I have seen some science fiction novels where spacesuits have some sort of self-sealing ability, analogous to World War II self-sealing fuel tanks. They make vague references to a fluid layer in the suit which turns solid when exposed to vacuum. I am not sure how practical this is. Others invoke some kind of unobtainium magic-tech nanotechnology where zillions of microscopic machines somehow repair the breech.

In The Expanse, asteroid ice miners who daily run the risk of suit punctures (or even losing limbs) wear special suits equipped with a series of automatic tourniquets. If an ice shard slices your hand off, the tourniquet in your forearm detects the local pressure drop, and seals the suit to your stump. Then you (or your buddies) can get you into an airlock, and into sickbay where hopefully your medical insurance will cover a prosthetic hand.

In the game Starfighter Inc. they have a more extreme system for their fighter pilots. If your body is damaged but your brain is intact, the Headshot Pilot Preservation System kicks in. The helmet decapitates and flash freezes the pilot's skull. Then it is ejected in the direction of a nearby friendly vessel for retrieval. At a medical center it can be revived and grafted on to a cloned body. An enemy ship might try to intercept the flying head, so they can ransom it back.


      These new ships were ugly as hell. Just an open framework with clamps to hold you in place, swiveled lasers fore and aft, small tachyon powerplants below the lasers. Everything automated; the machine would land us as quickly as possible and then zip off to harass the enemy. It was a one use, throwaway drone. The vehicle that would come pick us up if we survived was cradled next to it, much prettier.
     We clamped in and the assault ship cast off from the Sangre y Victoria with twin spurts from the yaw jets. Then the voice of the machine gave us a short countdown and we sped off at four gees' acceleration, straight down.
     The planet, which we hadn't bothered to name, was a chunk of black rock without any normal star close enough to give it heat. At first it was visible only by the absence of stars where its bulk cut off their light, but as we dropped closer we could see subtle variations in the blackness of its surface. We were coming down on the hemisphere opposite the Taurans' (enemy) outpost.
     Our recon had shown that their camp sat in the middle of a flat lava plain several hundred kilometers in diameter. It was pretty primitive compared to other Tauran bases UNEF had encountered, but there wouldn't be any sneaking up on it. We were going to careen over the horizon some fifteen klicks from the place, four ships converging simultaneously from different directions, all of us decelerating like mad, hopefully to drop right in their laps and come up shooting. There would be nothing to hide behind.
     I wasn't worried, of course. Abstractedly, I wished I hadn't taken the pill
.     We leveled off about a kilometer from the surface and sped along much faster than the rock's escape velocity, constantly correcting to keep from flying away. The surface rolled below us in a dark gray blur; we shed a little light from the pseudo-cerenkov glow made by our tachyon exhaust, scooting away from our reality into its own.
     The ungainly contraption skimmed and jumped along for some ten minutes; then suddenly the front jet glowed and we were snapped forward inside our suits, eyeballs trying to escape from their sockets in the rapid deceleration ("eyeballs-out" acceleration).
     "Prepare for ejection," the machine's female-mechanical voice said. "Five, four …"
     The ship's lasers started firing, millisecond flashes freezing the land below in jerky stroboscopic motion. It was a twisted, pock-marked jumble of fissures and random black rocks, a few meters below our feet. We were dropping, slowing.
     "Three—" It never got any farther. There was a too bright flash and I saw the horizon drop away as the ship's tail pitched down—then clipped the ground, and we were rolling, horribly, pieces of people and ship scattering. Then we slid pinwheeling to a bumpy halt, and I tried to pull free but my leg was pinned under the ship's bulk: excruciating pain and a dry crunch as the girder crushed my leg; shrill whistle of air escaping my breached suit; then the trauma maintenance turned on snick, more pain, then no pain and I was rolling free, short stump of a leg trailing blood that froze shiny black on the dull black rock. I tasted brass and a red haze closed everything out, then deepened to the brown of river clay, then loam and I passed out, with the pill thinking this is not so bad …
     The suit is set up to save as much of your body as possible. If you lose part of an arm or a leg, one of sixteen razor-sharp irises closes around your limb with the force of a hydraulic press, snipping it off neatly and sealing the suit before you can die of explosive decompression. Then "trauma maintenance" cauterizes the stump, replaces lost blood, and fills you full of happy-juice and No-shock. So you will either die happy or, if your comrades go on to win the battle, eventually be carried back up to the ship's aid station.
     We'd won that round, while I slept swaddled in dark cotton. I woke up in the infirmary.

From THE FOREVER WAR by Joe Haldeman (1975)



When you gotta go, you gotta go. A sudden urgent need to urinate or defecate when you are in a space suit during an EVA is a major problem.

NASA became aware of the need for space diapers on May 5, 1961. Freedom 7 was about to launch with astronaut Alan Shepard. NASA figured there was no need for a potty break, er, ah, "bladder evac" since the flight was only going to take 15 minutes. Alas there were several delays so poor Alan was on the pad for eight hours. He had to ask ground control for permission to pee in his suit, which was granted. Shorted out some of his medical sensors, though.

For the Gemini and Apollo programs they had a system for urination only. It was functionally equivalent to a condom (a "cuff") attached to a tube. The tube drained into a containment bag through a one-way valve. The cuff fit had to be snug or there would be dangerous leakage. The cuffs came in three sizes.

The space suit designers demonstrated a stunning ignorance of macho astronauts when they labeled the sizes "small", "medium", and "large".

Predictably, when asked which size they needed, all the testosterone-poisoned Right-Stuff astronauts answered "Large, of course."

After a few nasty incidents of space suits filling up with urine due to poorly fitting sheaths, the technicians re-named the sizes "large", "gigantic", and "humongous."

Unfortunately the best technology NASA currently has to offer is the "Maximum Absorbency Garment" (MAG). Which is basically a high-tech diaper. The MAG is full of sodium polyacrylate, which can absorb 300 times its weight in water. The MAG can hold about two liters of urine, blood, and/or feces. It was a challenge since conventional incontinence pants require gravity in order to operate.

Astronauts in free fall tend to have lots of urine to void when they finally feel the urge to go. Under normal gravity urine collects at the bottom of the bladder, triggering the urge when the bladder is one-third full. But in zero gee, urine in the bladder is floating around. The urge only comes when the bladder is almost totally full, causing pressure on the sides. Which is a problem since that much urine can press the urethra shut, making it hard to urinate. Astronauts are advised to schedule regualar pee breaks even if they do not feel the need.

Or the doc will have to open the first aid kit and break out the Foley catheter. That is not a threat, it is a promise.

The first time the condom and bag device was used in space was in John Glenn's 1962 orbital flight. He voided a full 27 ounces of urine in one go, which is about seven ounces more than the capacity of the average human bladder.


Schweickart: Yeah, it's not that much. But it's a fairly critical time, you know. When you're in there you don't have much choice, so you've got to design for it. Okay. So in the suit, for urine you use like a motorman's bag, which is basically composed of a bladder that holds about — boy, my numbers are really slipping Peter — but something between a liter and two liters, if I remember. A rubber bladder type of thing that sort of fits around your hips, and a rollon cuff which is essentially a condom with the end cut out that's rolled over a flapper-type valve, you know, just a rubber flapper valve. It forms a one-way check valve.

Warshall: Oh, I see, so you don't have to do anything.

Schweickart: No, you don't do anything. You just roll it on as part of the suit-donning procedure, and then urinate into it through the one-way valve. There are lots of little cute problems and uncertainties Unless you're an extremely unusual person, since the time you were about a year and a half old or so, you probably have not taken a leak laying flat on your back. And if you think that's easy, let me tell you, you've got some built-in psychological or survival programs, or something which you've got to overcome. So that's a tricky little thing. And then there's always the possibility that in maneuvering around in a suit you can end up pulling off the condom, and there's always — we have three sizes you know, small, medium and large — in diameter, and there's always this little ego thing about which one you do pick. of course the smart guy picks the right size, because it's very important. But what happens is, if you get too small a size it effectively pinches off the flow and you just turn yellow because you can't go; and if, on the other hand you've got an ego problem and you decide on a large when you should have a medium, what happens is you take your first leak and you end up with half of the urine outside the bag on you. And that's the last time you make that mistake. So it's a cute little trick there.

In terms of defecation inside the suit, there ain't no graceful way to do it. So what we do is, we wear what's affectionately called a fecal containment system. The good old FCS is essentially like a pair of bermuda shorts with a hole for your penis to stick out of to roll on this other thing, but fairly well sealed around there.

It's a tight fitting elastic type garment, and it fits especially tight around the thighs and around the waist. And it's just like a pair of diapers is what it is. made of material which obviously is non-permeable but still breathes and all it does is contain it. Now, to my knowledge, nobody's ever had to use that. But you wear it, because if you don't wear it, the consequences are rather drastic. Okay. So that sort of takes care of the in-the-suit situation.

Astronaut RUSSELL SCHWEICKART talking to Peter Warshall, collected in CoEvolution Quarterly Winter 1976-77

On Wednesday morning, NASA rewarded five members of the public — two doctors, a dentist, an engineer and a product designer — for their creative ideas for how to poop in a spacesuit.

Yes, it sounds a little bit funny. But unmet toilet needs could have life or death consequences for an astronaut in an emergency situation.

That's why thousands of people spent tens of thousands of hours on the "Space Poop Challenge," brainstorming, modeling, prototyping and number-crunching to come up with a crowd-sourced solution to the problem of human waste in a spacesuit.

Currently, astronauts on spacewalks rely on diapers, which is a feasible solution for only a few hours at a time. As we explained in November, NASA is imagining a situation where an astronaut is stuck in a spacesuit for days — like during an emergency on future Orion missions, which could take astronauts far from Earth.

The super-portable-bathroom solution has to work quickly, easily, in micro-gravity, without impeding movement, for both men and women, for solid and liquid waste. It can either store waste in the suit or expel it. And it has to be comfortable ... for up to six continuous days.

Since the project launched on the HeroX crowdsourcing site in October, nearly 20,000 people, from all over the world, submitted more than 5,000 ideas. They were competing for a total of $30,000 in prizes.

The winning solution came from Thatcher Cardon, an Air Force officer, family practice physician and flight surgeon. He says his design was inspired by minimally invasive surgical techniques — and a strong desire not to store the poop.

"I never thought that keeping the waste in the suit would be any good," he told NPR. "So I thought, 'How can we get in and out of the suit easily?' "

"I thought about what I know regarding less invasive surgeries like laparoscopy or arthroscopy or even endovascular techniques they use in cardiology — they can do some amazing things in very small openings.

"I mean, they can even replace heart valves now through catheters in an artery. So it should be able to handle a little bit of poop!"

He designed a small airlock at the crotch of the suit, with a variety of items — including inflatable bedpans and diapers — that could be passed through the small opening and then expanded. His design even allows an astronaut to change underwear while inside the spacesuit, through the same small opening.

Cardon used an old flight suit to try some physical prototyping, and his kids helped gather supplies. They were "totally excited," he says. "They lost their minds when I told them I won."

Second place went to a trio from Houston (the SPUDs team) — a physician, an engineering professor and a dentist (who also served as the team's illustrator). All three had studied chemical engineering in college.

Stacey Louie, the environmental engineer on the team, said the different areas of expertise on the team were central to their solution. But before they fine-tuned their design, they had to discard a lot of ideas.

For instance, doctor and team leader Jose Gonzales says that he immediately thought of some medicine-inspired strategies that would be effective — but not at all comfortable.

"You have to take into consideration, 'Is the astronaut going to be OK with this design?' " Katherine Kin, the dentist and artist, notes. "You have to have something that's psychologically comfortable."

So internal catheters were out. Instead, Gonzales says, they used an air-powered system to push waste away from the body to store it elsewhere in the suit. "More specifically, that air is created by passive and active normal body movements of the astronaut," Gonzales says.

A product designer from the U.K., Hugo Shelley, placed third. He usually works with electronics and tech products, but he says for this contest, he went in the other direction — and tried to build a solution with as few electronic parts as possible.

"I think we're all aware of the dangers of things going wrong in space," he says. A simple design seemed safer, he says.

"My mother's a textile designer so I think I started off really thinking about materials," he says. "Making something as comfortable as possible I thought was fairly important ... a lot of your mechanism really has to be in, effectively, the first few millimeters away from the skin."

His solution, the "SWIMSuit — Zero Gravity Underwear," disinfects and stores waste inside the suit, like the second-place design does.

Cardon won $15,000, while the trio from Houston took home $10,000 and Shelley netted $5,000.

The next step is for NASA to start prototyping the ideas, and get working versions of a waste-management system up to the International Space Station for testing.

Dustin Gohmert, the Orion crew survival system project manager at NASA, explains that NASA will combine existing ideas with elements of the winning designs to create a solution that will, indeed, go into space.

"Optimistically this will never be used, because it is a contingency scenario that something catastrophic has happened," he said. "But this will be on Orion and should something happen, and should it be called on to save the crew, this will be there and at their disposal."

Shelley, the product designer, notes that research on how to improve waste management inside a spacesuit could also be useful in "earth-bound applications" — for people with incontinence or in high-pressure, critical job situations.

And while it was "kind of odd" to think about poop in space for weeks at a time, he says the project was "quite exciting."

"Yes, it's an amusing thing to think about, but still it's a part of a spacesuit — and there's something incredibly thrilling about the space missions," he says.

And, he notes, "you can't fully appreciate being an interplanetary explorer if you've constantly got to use the bathroom and you can't."


On Earth, Andrew Lear's habits would have been no more than a character trait. In a hurry, he might choose mismatched socks. He might put off using the dishwasher for a day or two if he were involved in something interesting. He would prefer a house that looked "lived in." God help the maid who tried to clean up his study. He'd never be able to find anything afterward.

He was a brilliant but one-sided man. Backpacking or skin diving might have changed his habits — in such pursuits you learn not to forget any least trivial thing — but they would never have tempted him. An expedition to Mars was something he simply could not turn down. A pity, because neatness is worth your life in space.

You don't leave your fly open in a pressure suit.

A month after the landing, Childrey caught Lear doing just that.

The "fly" on a pressure suit is a soft rubber tube over your male member. It leads to a bladder, and there's a spring clamp on it. You open the clamp to use it. Then you close the clamp and open an outside spigot to evacuate the bladder into vacuum.

Similar designs for women involve a catheter, which is hideously uncomfortable. I presume the designers will keep trying. It seems wrong to bar half the human race from our ultimate destiny.

Lear was addicted to long walks. He was coming back from a walk, and he met Childrey coming out. Childrey noticed that the waste spigot on Lear's suit was open, the spring broken. Lear had been out for hours. If he'd had to go, he might have bled to death through flesh ruptured by vacuum.

From THE HOLE MAN by Larry Niven. 1974

Once I had one arm out it was pretty easy; I just crawled forward, putting my feet on the suit’s shoulders, and pulled on his free arm. He (the unconscious man) slid out of the suit like an oyster slipping out of its shell.

I popped the spare suit and after a lot of pulling and pushing, managed to get his legs in. Hooked up the biosensors and the front relief tube. He’d have to do the other one himself; it’s too complicated. For the nth time I was glad not to have been born female; they have to have two of those damned plumber’s friends, instead of just one and a simple hose.

I left his arms out of the sleeves. The suit would be useless for any kind of work, anyhow; waldos have to be tailored to the individual.

From THE FOREVER WAR by Joe Haldeman. 1975

Many people have written in to ask, “What is that silvery, liquescent lining inside the pants of spacesuits we occasionally see on your broadcasts?”

Well, viewers, that’s the sanitary nanopaste. You see, back in what we might call the pointy-stick era of spaceflight, the problem of the crew having to take a ‘fresher break while stuck in their vacuum suits for hours on end was handled by catheterization – it was necessary for astronauts to insert catheters into their urethra, rectum, cloaca, and/or any other excretory or partially-excretory orifices they might have in order to convey waste products to reservoirs for later disposal, and prevent them from contaminating the interior of the suit.

Apart from the occasional technical problems this had with leakage and providing pathways for infection, it was not a solution that was comfortable for anyone, or that anyone was comfortable with.

Fortunately, modern nanotechnology has provided the answer. Sanitary nanopaste selectively infiltrates one’s excretory orifices in a much more gentle manner than gross apparati (the sensation, I am told, being akin to mild tickling that rapidly becomes imperceptible), interfacing with the body’s own systems, and breaking down and compressing the body’s wastes in situ and conveying them directly and continuously, by molecular pass-the-parcel, to the vacuum suit’s recycling apparatus. In short: now, you simply never feel the need to excrete as long as you’re in your suit.

This is a much more elegant solution, obviously, and has satisfied virtually everyone – or at least everyone who isn’t overcome with squeamishness at the thought of microscopic robots roaming around in their bowels.

– Ixril Valenarius, Spaceflight Initiative Public Relations,
“This Week in Orbit”

Visual Identification

Once people are suited up, it does become hard to tell who is who. In Destination Moon, there were four spacemen, and each had a uniquely colored suit. Kind of like colored tooth-brushes, a different color for each family member.

But this won't work if you have more than a few spacemen, er, spacepeople. The person's name stenciled in large letter across the front and back is a possibility. Just like Mommy writing your name on your clothes when you go to summer camp.

Another possibility is for the suits to be color-coded by job. One color for the supervisors, once for the skilled workers, one for the newbies, etc. This is NOT recommended for the military, it just makes it easier for enemy snipers to kill the officers.


In Piers Anthony's The Kirlian Quest, he notes that this problem has occurred before: knights in armor are similarly inconveniently anonymous. The solution is coat of arms and heraldry. The knights wear their coats of arms on their shields, tabards, and horse barding, to identify themselves.

In other words, heraldry was a medieval form of an Identification Friend Or Foe system.

The British College of Arms was founded in 1484 to regulate heraldic coats of arms. A new noble would hire a herald to create a brand new coat of arms. The noble would suggest feats and other things they were proud of to the herald, who would try to depict them symbolically. The proposed heraldic "device" (coat of arms) is then submitted to the College of Arms to be evaluated. It is compared with all existing heraldic devices. The new device must have at least one major and one minor point of visual difference from those already registered. Otherwise it would be too easy to confuse the two devices in the heat of battle. Mistaking a foe for a friend could be fatal. It is also a good idea if the device can be recognized at a distance.

As an amusing side note, a heraldic device has a "blazon". This is a verbal description of the heraldic device done in heraldic terminology. If you give a herald a blazon, they can reproduce the original device even if they had never seen it before. Just remember that the "blazon" is the verbal description and "to emblazon" means to draw, paint or otherwise make a graphic representation of the device (called an "emblazonment").

If you find any illustrations of the game Warhammer 40,000, you will quickly see that the Space Marines are big fans of heraldry. Even though you can generally idenifty the bad Marines by the tentacles, weeping open sores, and other Marks of Chaos. Otherwise, if the opponents look like skeletons they are Necrons; if they are tall, skinny, and distainful they are Eldar; if they are green with tusks they are Orks; and if they look like Giger's Alien xenomorph on bad LSD and are eating everything they are Tyranids. They are all enemies, so the basic rule is if it does not look like a Space Marine, shoot it with your bolter.

2020 addenda: this was the year that the COVID-19 pandemic hit. Many wore protective face masks, which did interfere a person being recognized. And thousands of cottage industries suddenly sprang up, offering face masks with a variety of fancy patterns and even customizable designs. Everything old is new again, this is remarkably like the custom painted breathing masks from Heinlein's novel Red Planet.

Heraldry developed as a way to be seen and identified across a battlefield, in the clash of war. This requires high-contrast designs whose elements are clearly recognizable.

The first step in recognizability is to use the stylized heraldic forms of things. The second is to make your charges as big and bold as possible in the space you have available.

Modern corporate logos usually follow the same rules that heraldic artists used, because they want their product logo to stand out, to be identifiable even at a distance, and to be recognizable (ed note: all the easier for the shopper in the grocery store to instantly spot their brand). Consider the logos of Shell, Diamond Shamrock, BMW, Dodge, Purina, CBS — all of these follow the styles and rules of heraldry.

(ed note: indeed, if newly form corporation Alfa adopts a corporate logo that is too similar to an existing corporate logo used by corporation Bravo, Alfa will instantly be hit by a cease-and-desist lawsuit.)


Most Belters decorated their suits. Why not? The interior of his suit was the only place many a Belter could call home, and the one possession he had to keep in perfect condition. But even in the Belt, Nick Sohl's suit was unique.

On an orange background was the painting of a girl. She was short; her head barely reached Nick's neck ring. Her skin was a softly glowing green. Only her lovely back showed across the front of the suit. Her hair was streaming bonfire flames, flickering orange with touches of yellow and white, darkening into red-black smoke as it swept across the girl's left shoulder. She was nude. Her arms were wrapped around the suit's torso, her hands touching the air pac on its back; her legs embraced the suit's thighs, so that her heels touched the backs of the flexible metal knee joints. It was a very beautiful painting, so beautiful that it almost wasn't vulgar. A pity the suit's sanitary outlet wasn't somewhere else.

     Pictures, for instance. Phssthpok understood photographs, and he understood graphs and maps. But the three works of art on the back wall were neither. They were charcoal sketches. One showed the head of a native like Phssthpok's captive, but with longer crest of hair and with odd pigmentation around eyes and mouth; the others must have been younger editions of the same uncomfortably Pak-like species. Only heads and shoulders were shown. What was their purpose?
     Under other circumstances the design on Brennan's spacesuit might have provided a clue.
     Phssthpok had noticed that design and understood in part. For members of a cooperative, space-going subgroup, it would be useful to code spacesuits in bright colors. Others would recognize the pattern at great distances. The native's design seemed overcomplex, but not enough so to rouse Phssthpok's curiosity.
     For Phssthpok would never understand art or luxury.
     Luxury? A Pak breeder might appreciate luxury, but was too stupid to make it for himself. A protector hadn't the motivation. A protector's desires were all connected to the need to protect his blood line.
     Art? There had been maps and drawings among the Pak since before Pak history. But they were for war. You didn't recognize your loved ones by sight anyway. They smelled right.
     Reproduce the smell of a loved one?
     Phssthpok might have thought of that, had the painting on Brennan's chest been anything else. That would have been a concept! A method of keeping a protector alive and functioning long after his line was dead. It could have changed Pak history. If only Phssthpok had been led to understand representational art…
     But what could he make of Brennan's suit?
     Its chest was a copy in fluorescent dyes of Salvador Dalí's Madonna of Port Lligat. There were mountains floating above a soft blue sea, resisting gravity, their undersides flat and smooth. There were a woman and child, supernaturally beautiful, with windows through them. There was nothing for Phssthpok.

From PROTECTOR by Larry Niven (1973)

      A couple of nudists came in. They stood blinking among the booths while their eyes adjusted to the blue twilight, then converged with glad cries on the group two tables over. I watched and listened with an eye and an hear, thinking how different flatlander nudists were from Belter nudists. These all looked alike. They all had muscles, they had no interesting scars, they carried their credit cards in identical shoulder pouches, and they all shaved the same areas.

     … We always went nudist in the big bases. Most people did. It was a natural reaction to the pressure suits we wore day and night while out in the rocks. Get him into a shirtsleeve environment, and your normal Belter sneers at a shirt. But it’s only for comfort. Give him a good reason and your Belter will don shirt and pants as quickly as the next guy.

     But not Owen. After he got that meteor scar, I never saw him wear a shirt. Not just in the Ceres domes, but anywhere there was air to breathe. He just had to show that scar.

From DEATH BY ECSTASY by Larry Niven (1969)

(ed note: In the Cluster novels, the quotation mark symbols denote which species-language is being used. " is for humans, * is for Asts (looks like a mass of coils), / is for Slashes (looks like a living disk harrow, shooting laser beams), and :: is for Quadpointers (looks like a slug with four chisles on its nose). The protagonist Herald the Healer is a Slash.)

Whorl twined to another section of his convolute residence, and Herald followed. Here in the living rock bordering a corkscrew chamber was emblazoned in relief a creature-sized Shield of Arms.

It was beautiful. The outer shield was in the shape of an ellipse set at an angle, representing Galaxy Andromeda, bordered inside by a wreath of intertwining serpents to designate Sphere Ast. Within that were the Family Arms of Precipice, resembling an ornate overhanging cliff. Herald moved his loops across it, savoring its aspects. It had superior form, texture, and color, and was, in its fashion, a genuine work of art. The King of Arms of Ast was certainly a master!

*What do you find?* The query was urgent.

/I find an excellent and flawless emblazon./

*Did you not say 'blazon' before?*

The tedious questions of amateurs! But Herald repressed his annoyance, for courtesy was vital to his profession.

/I did, Whorl. The 'blazon' of a Shield of Arms is the precise linguistic specification of its elements. To 'emblazon' is to render this description into physical actuality./

*I comprehend. The one is the description, the other is the carving. I feared for a moment there was something wrong with it.*

/No, your Achievement is quite in order. Azurine, a cliff of thirty-seven rocks and forty-two rills, alternately thirteen, twelve, thirteen, seven, eleven, twenty-three, pearline, all within a bordure of the Serpents Rampant./

Herald winced inwardly as he communicated, for the old-style heraldic term "rampant" was restricted to certain quadrupedal beasts of prey, standing erect on the left foot raising the right foot in stride, balancing with the left forefoot outthrust, the right raised to strike. It was technically impossible for a legless serpent to be "rampant." But the broadening of the system to include diverse Cluster cultures had forced the fudging of some terms. However, as he had informed Whorl, the local Colleges of Arms defined legitimacy. So he had to accept it, nonsensical as it was in derivation. Regardless, this remained an excellent Shield of Arms, in concept and execution.

In a moment she was back on the subject. ::How did heraldry start?::

/Many species, in their pretechnical phases, wore special apparel to protect them from the attacks of physical weapons. This apparel was called 'armor,' and it was so encompassing that it became impossible to recognize the individual entity within it, the 'knight,' which figure is also represented in the Tarot deck. Therefore it became necessary to decorate his shield with some characteristic design, typical of his household and affiliation, so that friend could be distinguished from enemy. This eliminated the awkwardness of a knight lining up behind the formation of his enemy, supposing he was among friends. Or even attacking his friends, thinking they were enemies. The markings on the shield made everything instantly clear, even when the knights were not personally known to each other. This was the origin of heraldry. Today, all great families of all species in the Cluster have their registered Shields of Arms, even though they may never engage in combat./

::My family has a Shield! I never knew what it meant.::

/Come, I will explain what it means./ Following her directions, Herald located the Metamorphic Shield and placed it against the wall where both could view it. /Note that the shape of this Shield is elliptical, a kind of angled oval that signifies Galaxy Andromeda./

::But Andromeda is a spiral!::

/So it is. But from Milky Way it appears elliptical. (Since Andromeda lost the Wars of Energy, we suffer the additional humiliation of the ellipse. The Milky Way Shield is the fundamental shape, flat across the top, round or partly pointed across the bottom. Other Galaxies have other shapes.) Within this is the band of prints, the little four-point patterns, signifying Sphere Quadpoint. In Milky Way there are two bands, since that Galaxy is organized into segments and Spheres, but it is the same idea. Then the main design, the symbol of Family Metamorphic: a lump of edible rock superimposed on the geologic flowchart of its derivation. A distinctive Achievement—that is what the complete affair is called—recognizable anywhere in the Cluster./

::Can you recognize any Shield of Arms in the whole Cluster?:: she asked, a bit awed.

/Within certain broad categories, yes. It is my business. And this is true generally. Two completely alien sapients could meet on a barren planetoid, perhaps shipwrecked from different vessels, possessing no common language, form or status, and they could recognize each other by their Shields of Arms. That would provide their common experience. Each would know the other was sapient and civilized, and where he was from, and that he honored Cluster conventions of behavior./

From KIRLIAN QUEST by Piers Anthony ()

     The tiger stripes on Jim's mask, the war paint on Frank's, and a rainbow motif on Phyllis's made the young people easy to identify. The adults could be told apart only by size, shape, and manner; there were two extras, Doctor MacRae and Father Cleary.

     He (headmaster Howe) poked his head inside, seemed about to leave, then came inside. He pointed to their outdoor suits, hanging on hooks by the clothes locker. 'Why haven't you removed those barbaric decorations from your masks?'
     The boys looked startled; Howe went on, 'Haven't you looked at the bulletin board this morning?'


1. The practice of painting respirator masks with so-called identification patterns will cease. Masks will be plain and each student will letter his name neatly in letters one inch high across the chest and across the shoulders of his outdoors suit.

(ed note: headmaster Howe is a stupid little power-mad bureaucrat who does not understand the realities of life out on the frontier)

From RED PLANET by Robert Heinlein. 1949

Safety Line

For strict safely, static lines or safety lines are mandatory. The line will have to be made of special materials, since most terrestrial ropes and cables will turn glass-like and shatter in vacuum.

The spacecraft should have plenty of small steel rings bolted at regular intervals over the hull for spacemen to attach their safety lines to. Without a static line, an astronaut who manages to get both magnetic boots separated from the hull will suddenly find themself on a slow impromptu tour of the solar system. If their spouses are real lucky the bodies might actually be eventually recovered for burial.

In the real world NASA generally always insisted that astronauts performing a spacewalk be tethered to the spacecraft or station. The first NASA untethered spacewalk was Bruce McCandless II's little jaunt with NASA MMU in Challenger mission STS-41-B.

Another useful item is a "line throwing gun". This allows one to shoot a safety line from one spacecraft to another.

There was an impressive use of tethers in episode #4 of The Expanse.

Our heroes are in the hangar bay of the Martian battleship Donnager. The ship has been boarded by hostiles, the captain is poised to scuttle, and our heroes had better get into the escape ship fast unless they want to die in the scuttling.

The Donnager is under 1 g acceleration so there is artficial gravity. Our heroes have been instructed to turn off their boot magnets and run as fast as they can across the gantry into the escape ship, while dodging gunfire.

Alas our heroes Naomi and Holden are only half way across the gantry when the Donnager is forced to turn off its engines. They are suddenly in free fall, and float helpessly away from the gantry.

But Holden is a seasoned, cool-thinking, steely-eyed spaceman. He grabs Namoi, attaches a tether connecting the two, then kicks Naomi upwards away from the gantry. Newton's Third Law to the rescue! Holden recoils to the gantry, his magnetic boots latch on, then he uses the tether to haul Naomi down to the gantry.

Brilliant use of a tether, and a astonishing use of real physics in a TV show.


     Holden grabbed for Naomi. He struggled to orient himself as the two of them spun across the bay with nothing to push off of and nothing to arrest their flight. They were in the middle of the room with no cover.
     The blast had hurled Kelly five meters through the air and into the side of a packing crate, where he was floating now, one magnetic boot connected to the side of the container, the other struggling to connect with the deck. Amos had been blown down, and lay flat on the floor, his lower leg stuck out at an impossible angle. Alex crouched at his side.
     Holden craned his neck, looking toward the attackers. There was the boarder with the grenade launcher who had blasted Kelly, lining up on them for the killing shot. We 're dead, Holden thought. Naomi made an obscene gesture.
     The man with the grenade launcher shuddered and dissolved in a spray of blood and small detonations.
     "Get to the ship!" Gomez screamed from the radio. His voice was grating and high, half shrieking pain and half battle ecstasy.
     Holden pulled the tether line off Naomi's suit.
     "What are you...?" she began.
     "Trust me," he said, then put his feet into her stomach and shoved off. Hard. He hit the deck while she spun toward the ceiling. He kicked on his boot mags and then yanked the tether to pull her down to him.
     The room strobed with sustained machine gun fire — Holden said, "Stay low," and ran as quickly as his magnetic boots would allow toward Alex and Amos. The mechanic moved his limbs feebly, so he was still alive. Holden realized he still had the end of Naomi's tether in his hand, so he clipped it on to a loop on his suit. No more getting separated.

From LEVIATHAN WAKES: Book One of The Expanse by James A. Corey (2011)

Fred braced himself in the open hatch and fired the line-throwing gun. The foam plastic projectile sailed slowly across the void, trailing the line it pulled from the container on the gun. A P-suited figure reached out and caught the slow-moving plastic blob as it sailed past. Fred snubbed the line on a cleat inside the hatch as the other person whipped it through and around a beam of the array. Torn had his running safety line snapped around the main line as quickly as it was secured at both ends. He pushed off and sailed down the line. Fred was behind him.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

     I knew exactly where Mac had gone, but I had a hard time seeing him. The rock slide had carried with it a mixture of small and large fragments, from gravel and pebbles to substantial boulders. His struggles to climb the slope had only managed to embed him deeper in loose materials. Now his suit was three-quarters hidden. His efforts also seemed to have carried him backwards, so with a thirty degree gradient facing him I didn't think he'd ever be able to get out alone. And further down the slope lay a broad fissure in the surface, of indeterminate depth.
     He was facing my way, and he had seen me too. "Jeanie, don't come any closer. You'll slither right down here, the same as I did. There's nothing firm past the ledge you're standing on."
     "Don't worry. This is as far as I'm coming." I backed up a step, nearer to a huge rock that must have weighed many tons, and turned my head so the chest of Mac's suit sat on the crosshairs at the exact center of my display. "Don't move a muscle now. I'm going to use the Walton, and we don't have time for second tries."
     I lifted the crosshairs just a little to allow for the effects of gravity, then intoned the Walton release sequence. The ejection solenoid fired, and the thin filament with its terminal electromagnet shot out from the chest panel on my suit and flashed down towards McAndrew. The laser at the tip measured the distance of the target, and the magnet went on a fraction of a second before contact. Mac and I were joined by a hair-thin bond. I braced myself behind the big rock. "Ready? I'm going to haul you in."
     "Aye, I'm ready. But why didn't I think of using the Walton? Damnation, I didn't need to get you back here, I could have done it for myself."
     I began to reel in the line, slowly so that Mac could help by freeing himself from the stones and gravel. The Izaak Walton has been used for many years, ever since the first big space construction jobs pointed out the need for a way to move around in vacuum without wasting a suit's reaction mass. If all you want is a little linear momentum, the argument went, why not take it from the massive structures around you? That's all that the Waltons do. I'd used them hundreds of times in free fall, shooting the line out to a girder where I wanted to be, connecting, then reeling myself over there. So had Mac, and that's why he was disgusted with himself. But it occurred to me that this was the first time I'd ever heard of a Walton being used on a planetary surface.
     "I don't think you could have done it, Mac," I said. "This big rock's the only solid one you could see from down there, and it doesn't look as though it has a high metal content. You'd have nothing for the magnet to grab hold of up here."
     "Maybe." He snorted. "But I should have had the sense to try. I'm a witless oaf."
     What that made me, I dreaded to think. I went on steadily hauling in the line until he had scrabbled his way up to stand by my side, then switched off the field. The line and magnet automatically ran into their storage reel in my suit, and we carefully turned and headed back to the other two.

From ROGUEWORLD by Charles Sheffield (1983 )

(ed note: The space family Stone has purchased a second hand NTR and was on a trip to Mars. The twin teenagers Castor and Pollux purchased a load of used bicycles hoping to sell them on Mars. An emergency forced them to temporarily jettison the bikes so as to increase the delta-V of the ship for a rescue mission. After the mission they are trying to bring the bicycles back to the ship.)

      Outside the bicycles looked considerably farther away. Cas glanced at the mass and said, "Maybe I ought to go across on my suit jet, Dad? It would save time."
     "I strongly doubt it. Try the heaving line, Pol."
     Pollux snapped the light messenger line to a padeye. Near the weighted end had been fastened a half a dozen large hooks fashioned of 6-gauge wire. His first heave seemed to be strong enough but it missed the cluster by a considerable margin.
     "Let me have it, Pol," Castor demanded.
     "Let him be," ordered their father. "So help me, this is the last time I'm going into space without a proper line-throwing gun. Make note of that, Cas. Put it on the shopping list when we go inside."
     "Aye aye, sir."
     The second throw was seen to hit the mass, but when Pol heaved in the line came away, the hooks having failed to catch. He tried again. This time the floating line came taut.
     "Easy, now!" his father cautioned. "We don't want a bunch of bikes in our lap. There—'vast heaving. She's started." They waited.
     Castor became impatient and suggested that they give the line another tug. His father shook his head. (Grandmother) Hazel added, "I saw a green hand at the space station try to hurry a load that way. Steel plate, it was."
     "What happened?"
     "He had started it with a pull; he thought he could stop it with a shove. They had to amputate both legs but they saved his life." Castor shut up.

     The two ships, perfectly matched to eye and almost so by instrument, nevertheless had drifted a couple of miles apart while the epidemic in the liner raged and died out. The undetectable gravitational attraction between them gave them mutual escape velocity much less than their tiny residual relative motion. Up to now nothing had been done about it since they were still in the easiest of phone range. But now it was necessary to pump reactive mass from one to the other.
     Roger Stone threw a weight fastened to a light messenger line as straight and as far as he could heave. By the time it was slowed to a crawl by the drag of the line a crewman from the War God came out after it on his suit jet. In due course the messenger line brought over a heavier line which was fastened to the smaller ship. Hand power alone took a strain on the line. While the mass of Rolling Stone was enormous by human muscle standards, the vector involved was too small to handle by jet and friction was nil. In warping in a space ship the lack of brakes is a consideration more important than power, as numerous dents to ships and space stations testify.

From THE ROLLING STONES by Robert Heinlein (1952)

Things get real nasty if the ship is a tumbling pigeon or otherwise rotates to provide artificial gravity. The poor EVA spacemen have to swing from hand-hold to hand-hold like trapezes artists. From their viewpoint, the spacecraft is overhead and below is a long fall to infinity. For details read Heinlein's short story "Ordeal in Space".


Astronauts also have to watch what they say. There is no air in space, so unless you are touching helmets together, you cannot talk with others without a radio. But while speaking on Terra means your voice becomes fainter with distance, over a radio it will be loud and clear out to the limit of the radio's range. This means cursing under your breath or muttering behind somebody's back will not work. There might be several channels to allow a bit of privacy, or if several conversations are going on at once.

"Do you think they're listening to us? Suppose someone's got a watch on this frequency—they'll have heard every word we've said. After all, we're in direct line of sight."

"Who's being melodramatic now? No one except the Observatory would be listening on this frequency, and the folks at home can't hear us as there's rather a lot of mountain in the way. Sounds as if you've got a guilty conscience; anyone would think that you'd been using naughty words again."

This was a reference to an unfortunate episode soon after Wheeler's arrival. Since then he had been very conscious of the fact that privacy of speech, which is taken for granted on Earth, not always available to the wearers of spacesuits, whose every whisper can be heard by anyone within radio range.

From EARTHLIGHT by Sir Arthur C. Clarke (1955)

Designed to improve worker safety in remote, dangerous or noisy workplaces, Intellinium's smart safety shoes feature built-in telecommunications that can send and receive alerts or write short text messages without using your hands.

      Boots that let you send text messages with your feet were unveiled at Mobile World Congress in Barcelona last week. Designed to improve worker safety in remote, dangerous or noisy workplaces, Intellinium's smart safety shoes feature built-in telecommunications that can send and receive alerts or write short text messages without using your hands.
          Using a simple Morse code-inspired series of dots and dashes, wearers can squeeze a button on the side of the shoe to write and send a message or acknowledge an incoming text. Embedded in the toe-cap of the shoe, however, is a sensor that allows the wearer to perform the same function hands-free. 
         "You can use with your toe to send some signals especially if your arms are broken or in case of danger and you want to send some signals then you use your feet," Mathieu Destrian, founder of start-up Intellinium, told Reuters. Tapping your big toe against the top of the toe-cap makes dots and dashes that translate to a number of predefined messages.  We made some things simpler meaning that with a dash and dot you can send an SOS mayday. So for instance, to send an alert it's two seconds you press and it's a dash. You release. You press again to confirm and there the alert is sent outside," added Destrian.

         The shoe has other safety features too, like sending a "mayday" alert in case of injury. If you are unconscious, if you don't move for instance, the shoe can detect that you do not move any more. It will try to wake up you with vibration here. If you do not answer with vibration then a signal will be sent out to other colleagues close to your place or to your employer. Built-in sensors detect falls or shocks, and immediately alert the employer or a colleague of the worker's location to enable faster response.

         Intellinium, based in France, has partnered with communications company Sierra Wireless to provide multi-operator coverage for their smart shoes.
         "The type of message that we are sending is very simple, so based on a kind of Morse code. So it has a smaller throughput, so very light information. So we have a long lasting battery from one month to three months," said Sierra's Jean-Francois Pinson. Destrian added: "In Europe we cover 100-percent of all European telecom operators, which brings better penetration in buildings and better coverage."
        He added they're now working to refine and test their smart shoe in a number of industries, including construction sites, factories, mines and oil platforms.


Sometime people on a space walk want to communicate but do not want to use radio. This can be either due to the sad fact that one or both of the radio sets are out of order, or if the two have a strong motive not to broadcast their conversation to everybody in the universe within radio range.

  • Some SF novels suggest that two space suited people might turn off their raidos, and touch helmets. The theory is that the sound of the conversation will be conducted through the contact between helmets. However, others maintain that the area of contact will be so small (since the helmets are basically spherical) that no audible sound will manage to pass.

  • In Poul Anderson's TAU ZERO, he suggests astronauts will learn how to read lips. In the weaving sheds and cotton mills of Lancashire, workers developed an exaggerated form of speech and gesture called mee-mawing to facilitate lip-reading.

  • They can use a vacuum-rated marker pen to write words or Spacer's Runic.

  • Morse Code is another possibility, via flashlight or a mirror reflecting Sol. If they are connected by something that will transmit vibration (like a girder) they can use tap codes (Morse won't work with percussion because while you can tap a "dot" you cannot tap a "dash").

  • In The Expanse Belters use specialized hand gestures similar to those used by scuba divers and harbor crain longshoremen. These can also be used like Emoticons to supplement radio communication, e.g., using a fist to make a "nod-your-head-yes" gesture (non-verbal so radio doesn't send it, and mostly invisible unless you can see inside their helment). In The Expanse, Belters tend to use hand gestures even when not wearing a space suit, shrugging with their hands instead of their shoulders for instance.

  • In Larry Niven's "Known Space" series, belters do NOT perform any hand gestures at all. This is because Niven's belters fly in very small spacecraft called "singleships". The habitat module is only slightly larger than a coffin.
    "You noticed a habit of mine once. I never make gestures. All Belters have that trait. It's because on a small mining ship you could hit something waving your arms around. Something like the airlock button."
    "Sometimes it's almost eerie. You don't move for minutes at a time."
    The Warriors (1966)

  • Actually, NASA is looking into creating some "official" hand signals. The link shows some proposed signals.

  • In the Fate Space Toolkit RPG, spacesuit operating systems can be controlled by gesture commands based hand signals. A system of hand signals is called a "fist". Different asteroid colonies often have different fists, much like dialects or even totally different languags.

  • One can use deaf sign language or a manually coded oral language. It is difficult to do full blown sign language in a space suit. Sign languages have complicated, nuanced signs that would get lost by the highly restricted motion of the suits. Only big motions would be visible.

  • If the two are connected by a tether, they can use scuba diver rope signals.

  • Sawmill workers had their own specialized hand signal language, because the noise in the mill is too loud for speaking. Something similar is used in steel pipe mills, where even radios are worthless due to the background noise.

Pete Wildsmith had a couple of good points about sign language in space suits:

  • At long distances, sign language or hand gestures may be difficult to see. A flag semaphore dialect may be developed for such cases. The signals are indicated by holding one's two arms (with or without flags, lit wands, paddles, or other optical devices) at various angles to the body. Since arms are bigger than hands, the signal is distinguishable at greater distances.

  • Both sign language and semaphore will be limited by conservation of angular momentum. Meaning if the person does not have their feet anchored while in free-fall, moving their arms will cause the entire body to rotate.


user56903: Usual SciFi scene. In a spacesuit, in vacuum, with the comms out for some reason. They want to talk, so they butt helmets together so sound can pass through. Questions are:

a) Would it really work in practice?
b) It it did, could they talk normally or have to shout?
c) Are all frequencies going to pass equally, or are there high and low frequency cutoffs, filters, resonances etc?

Assume helmets are spherical, which means the contact area is small.



1) As most people answered here mention, it would definitely work. A very good example of such technology is the bone-conducting "headphones". One can find some examples in this, this and this links (the last has some more extra information). In addition, this technology has been in an experimental phase for the US Army. Although this is not in direct connection to the exact nature of the question, one could easily find more "common" every-day examples such as the transmission of noise through structural elements in buildings (it's quite common in bad constructions to be able to hear neighbours a couple of floors up- or downstairs). So yes, this should work.

2) This is way too complicated to be able to answer with one word (shout or normal voice). As we all know, sound transmission is a quite complex phenomenon to be able to describe it so easy (especially when psychoacoustics jump in). By utilising the knowledge we have from noise transmission we could (at least as a first approximation) consider the case you describe as another "transmission through a structure" case (it could serve as a qualitative way to approach the "problem). We know that when one constructs double-leaf partitions for sound insulation the studs are a major issue. A considerable (for sound insulation standards at least) amount of energy is transmitted through the studs to the other side of the partition to be re-radiated. In addition to that, considering that in our case both helmets will most probably be made from the same material (this means that we have impedance matching, which constitutes a very nice condition for transmission) internal reflections and/or attenuation are minimised.

On the other hand, the area that the helmets touch are most probably gonna be quite small. But, if we also think about flanking transmissions, we'll see that it is possible to have considerable transmission through this small area and the whole helmet act as a radiator (this is kind of speculative, as the whole structure is quite complex to be able to make conclusions). This means that most probably a reasonable amount of incident energy would be required to manage to get enough sound energy on the "other side", but I don't think that it would have to be out of the possibilities of a normal individual. Most probably above normal speaking voice (this is considered to be about 60 — 70 dBSPL in about 1m distance) but not extremely loud.

3) Well, I am sure we all know that no medium has a "flat frequency response". As is quite common in pretty much the vast majority of media, solids too, exhibit increasingly higher attenuation as the frequency goes up. In the "sound insulation world", it is considered to be about 6dB/oct for the region of the so-called mass-law and about 12dB/oct above the coincidence frequency. In practice, the values seem to somehow approach a maximum value (or it is just because we can't measure the increasing attenuation due to our equipment and space noise limitations). So, that means that also, in this case, not all frequencies will be transmitted with equal magnitude/amplitude.


      (ed note: the space cadets are on the hull of the spacecraft, being trained by Sergeant Hanako to use the space suit's rocket jets)

     A little more than a minute after cutting his jet, he jack-knifed to bring his boots in front of him and clicked on, about ten feet from the instructor.
     Hanako came over and placed his helmet against Mart’s so he could speak to him privately, with the radio shut off. “A good job, kid, the way you kept your nerve when you swung past. Okay—I’ll post you for advanced training.”
     Matt remembered to cut out his walky-talky. “Gee, thanks!”
     “You did it, not me.” Hanako cut back in the voice circuit. “Okay, there—number four.”
     Matt wanted to chase back to his room, find Tex, and do some boasting. But there were seven more to go. Some did well, some had to be fished out of difficulty.

     The last man outdid himself. He failed to cut off his power in spite of Hanako’s shouts for him to do so. He moved away from the ship in a wide curve and commenced to spin, while the sergeant whipped at the safety line to try to stop the spin and head him back. At the end of a long fifty seconds his power gave out; he was nearly a thousand feet away and still receding rapidly.
     The sergeant played him ike a fisherman fighting a barracuda, then brought him in very, very slowly, for there was no way to check whatever speed the tension on the line placed on him.
     When at last he was in, clicked down, and anchored by static line, Hanako sighed. “Whew!” he said. “I thought I was going to have to go get him.” He went to the cadet and touched helmets, radio off.
     The cadet did not shut off his instrument. “I don’t know,” they heard him reply. “The switch didn’t go bad—I just couldn’t seem to move a muscle. I could hear you shouting but I couldn’t move.”
     Matt went back to the airlock with the group, feeling considerably sobered. He suspected that there would be a vacant place at supper. It was the Commandant’s policy to get a cadet who was to be dropped away from the ship without delay. Matt did not question the practice, but it jarred him when he saw it happening—it brought the cold breath of disaster on his own neck.

From SPACE CADET by Robert Heinlein (1948)

      To the surprise of the twins Hazel did not continue the argument but followed her son docilely into the air lock. Mr Stone started down the rope ladder; Castor pulled his grandmother aside, switched off both her radio and his and pushed his helmet into contact with hers so that he might speak with her in private. ‘Hazel, what was wrong with the power plant? Pol and I went through this ship last week — I didn’t spot anything too bad.’
     Hazel look at him pityingly. ‘You’ve been losing sleep lately? It’s obvious — only four couches.’
     ‘Oh.’ Castor switched on his radio and silently followed his brother and father to the ground.

(ed note: context: Teenagers Castor and Pollux Stone want to buy a spaceship and make their fortunes in the asteroid belt. Mr. Stone thinks the twins are far too young to go gallivanting off by themselves. He decides to go shopping for a used four-accelerator-couch ship so he, his wife, grandmother Hazel, and the baby can go traveling. Castor and Pollux can stay home and go to boarding school.

Wiley grandmother Hazel is manipulating her son Mr. Stone into getting a ship that the entire family can fit in. As they look over a used ship that Mr. Stone favors, Hazel pitches a fit about the state of the ship's power plant. Mr. Stone demurrers to his mother's judgement. The twins know there is nothing wrong with the plant and ask grandmother Hazel what gives?)

From THE ROLLING STONES by Robert Heinlein (1952)

( ed note: on Luna, Kip and Peewee put on spacesuits and make their escape from the alien base)

     "Mind your pressure. Kip. You're swelling up too fast." I kicked the chin valve while watching the gauge—and kicking myself for letting a little girl catch me in a greenhorn trick. But she had used a space suit before, while I had merely pretended to.
     I decided this was no time to be proud. "Peewee? Give me all the tips you can. I'm new to his."
     "I will, Kip."
     The outer door popped silently and swung inward—and I looked out over the bleak bright surface of a lunar plain. For a homesick moment I remembered the trip-to-the-Moon games I had played as a kid and wished I were back in Centerville. Then Peewee touched her helmet to mine. "See anyone?"
     "We're lucky, the door faces away from the other ships. Listen carefully. We won't use radio until we are over the horizon—unless it's a desperate emergency. They listen on our frequencies. I know that for sure. Now see that mountain with the saddle in it? Kip, pay attention!"
     "Yes." I had been staring at Earth. She was beautiful even in that shadow show in the control room—but I just hadn't realized. There she was, so close I could almost touch her … and so far away that we might never get home. You can't believe what a lovely planet we have, until you see her from outside … with clouds girdling her waist and polar cap set jauntily, like a spring hat. "Yes. I see the saddle."
     "We head left of there, where you see a pass. Tim and Jock (thugs working for the aliens) brought me through it in a crawler. Once we pick up its tracks it will be easy. But first we head for those near hills just left of that—that ought to keep this ship between us and the other ships while we get out of sight. I hope."
     It was twelve feet or so to the ground and I was prepared to jump, since it would be nothing much in that gravity. Peewee insisted on lowering me by rope. "You'll fall over your feet. Look, Kip, listen to old Aunt Peewee. You don't have Moon legs yet. It's going to be like your first time on a bicycle."
     So I let her lower me and the Mother Thing while she snubbed the nylon rope around the side of the lock. Then she jumped with no trouble. I started to loop up the line but she stopped me and snapped the other end to her belt, then touched helmets. "I'll lead. If I go too fast or you need me, tug on the rope. I won't be able to see you."

From HAVE SPACE SUIT, WILL TRAVEL by Robert Heinlein (1958)

(ed note: "Tiny" Larsen is the man in charge of buiding Space Station One. Which is an engineering feat bigger than the Panama Canal. His construction crew is stag, all male, by design. He has to fire one of the radiomen when they invent a magnetic way of gambling with dice in free fall, including cheating. The replacement, G. Brooks McNye arrives by rocket. But the rocket departs before Tiny discovers the "G" is for "Gloria".

Tiny figures construction crew moral will tank, and keeps her chaperoned as much as possible. Which isn't much since they need two radiomen to cover all the shifts. Gloria is competent enough, as a matter of fact she trained the current radioman.

Things get testy on the day when they perform the dangerous operation of spinning up the station using JATO units.)

     Men in space suits all look alike; we used numbers and colored armbands. Supervisors had two antennas, one for a gang frequency, one for the supervisors' circuit. With Tiny and me the second antenna hooked back through the radio shack and to all the gang frequencies—a broadcast.
     The supervisors had reported their men clear of the fireworks and I was about to give Tiny the word, when this figure came climbing through the girders, inside the danger zone. No safety line. No armband. One antenna.
     Miss Gloria, of course. Tiny hauled her out of the blast zone, and anchored her with his own safety line. I heard his voice, harsh in my helmet: "Who do you think you are? A sidewalk superintendent?"
     And her voice: "What do you expect me to do? Go park on, a star?"
     "I told you to stay away from the job. If you can't obey orders, I'll lock you up."
     I reached him, switched off my radio and touched helmet. "Boss! Boss!" I said. "You're broadcasting!"
     "Oh—" he says, switches off, and touches helmets with her. We could still hear her; she didn't switch off. "Why, you big baboon, I came outside because you sent a search party to clear everybody out," and, "How would I know about a safety line rule? You've kept me penned up." And finally, "We'll see!"

(ed note: As it turned out, Tiny was wrong. The construction crew moral soared, and construction was actually ahead of schedule.)

From DELILAH AND THE SPACE-RIGGER by Robert Heinlein (1949)

      Something smashed into his back with a force that knocked the breath out of him. For a heart-freezing moment he thought his air-tanks had gone, his suit torn open and that he was already sucking frenziedly at vacuum. But his gasp of pure terror brought air rushing into his lungs. Conway had never known canned air to taste so good.
     The AACL’s tentacle had only caught him a glancing blow—his back wasn’t broken—and the only damage was a wrecked suit radio.
     “Are you all right?” Conway asked anxiously when he had Williamson settled in the compartment above. He had to press his helmet against the other’s—that was the only way he could make himself heard now.
     For several minutes there was no reply, then the weary, pain-wrecked near-whisper returned.
     “My arms hurt. I’m tired,” it said haltingly. “But I’ll be OK when… they take me… inside.” Williamson paused, his voice seemed to gather strength from somewhere and he went on, “That is if there is anybody left alive in the hospital to treat me. If you don’t stop our friend down there…”
     Sudden anger flared in Conway. “Dammit, do you never give up?” he burst out. “Get this, I’m not going to kill an intelligent being! My radio’s gone so I don’t have to listen to Lister and Mannon yammering at me, and all I’ve got to do to shut you up is pull my helmet away from yours.

From HOSPITAL STATION by James White (1962)

Lindgren and Reymont exchanged a look above his bent back. She shaped unspoken words. Once he had taught her the Rescue Corps trick of lip reading when spacesuit radios were unusable. They had practiced it as something that made them more private and more one.

From TAU ZERO by Poul Anderson (1970)

(ed note: This is about working in British weaving sheds in the early 1900s)

     A weaving shed in full song is a noisy animal, the roar would be disconcerting to anyone not used to it. None of the weavers wore ear defenders and many had a low level of hearing loss after years of exposure. Many thousands of pounds were spent on experiments to lessen the noise but all of them failed and right to the end of the industry the Lancashire loom made as much noise as it did when it was first invented.
     There was one small consolation, the noise was low frequency and nowhere near as damaging as modern high speed looms so it wasn’t as bad as some would like to portray it. However, it made communication in the shed by normal speech almost impossible.
     The weavers found a way round this, they used to ‘mee maw’ to each other. This was using exaggerated lip movements With no sound so they can lip-read each other. If a weaver wanted to say something privately to another weaver she would place her mouth very close to her friend’s ear so nobody could see her lip movements. If I wanted to spread a message round the shed, say if I was stopping early for some reason, all I had to do was go to the door of the shed, mee maw my message to the first weaver inside the door and before I had walked back to the engine house everyone in the shed had the message.

From BANCROFT by Stanley Graham (2009)

      They stopped at the Locker Rooms at East Lock and suited up. As usual, (grandmother) Hazel unbelted her gun and strapped it to her vacuum suit. None of the others was armed; aside from civic guards and military police no one went armed in Luna City at this late date except a few of the very old-timers like Hazel herself. Castor said ‘Hazel, why do you bother with that?’
     ‘To assert my right. Besides, I might meet a rattlesnake.’
     ‘Rattlesnakes? On the Moon? Now, Hazel!’
     ‘“Now, Hazel”’ yourself. More rattlesnakes walking around on their hind legs than ever wriggled in the dust. Anyhow, do you remember the reason the White Knight gave Alice for keeping a mouse trap on his horse?
     ‘Uh, not exactly.’
     ‘Look it up when we get home. You kids are ignorant Give me a hand with this helmet.’
     The conversation stopped, as Buster was calling his grandmother and insisting that they start their game. Castor could read her lips through her helmet; when he had his own helmet in place and his suit radio switched on he could hear them arguing about which had the white men last game. Hazel was preoccupied thereafter as Buster, with the chess board in front of him, was intentionally hurrying the moves, whereas Hazel was kept busy visualising the board.

From THE ROLLING STONES by Robert Heinlein (1952)

"We'll already have stopped," Holden said, and McDowell patted at the air with his wide, spidery hands. One of the many Belter gestures that had evolved to be visible when wearing an environment suit.

From LEVIATHAN WAKES by "James S.A. Corey" 2011. First novel of The Expanse

(ed note: Rick is only 15 years old, on his first trip to the moon colony. He is excited about his first lunar excursion with the local scouting troop. Unfortunately he does not understand the 24 hour clock, so arrives at the debarking airlock twelve hours early.)

It was eight forty-five when he reached the recessed doorway that was one of the entrances to the North-Down lock area.

Sensors responded to his arrival, triggering a flashing light—green, since there was safe pressure on the other side of the door. Rick, as he had been taught, flicked the "acknowledge reading" switch located high on the door frame. Then he activated the door switch itself. Despite the need for power economy, doors on the moon that opened into areas even moderately likely to tap vacuum were motor-driven. The chamber Rick entered was not normally exhausted; it was a sort of combined garage and locker-room. However, it did have a large direct exit to the surface for getting out unusually large pieces of equipment. When so used it became an air-lock chamber.

On every moon-dweller's mind there was always the possibility of leakage or outright valve failure in any outer room. Rick was aware of that threat, just as the schoolkids he had met a few days before had been aware of rain and cold on Earth. It was the Big Difference everyone was told about. But awareness was not the same thing as the reflective self-protection of a native.

With the door secured behind him-by a strictly manual latch, activation of which shut off a warning bell—he made his way to the main personnel exits. His fervent hope was that the group might still be there.

"Sir, I seemed to have missed a group going out to Picard G. Could you tell me how long ago they left?"

Montaux shook his head, at the same time making the negative hand-gesture habitual to people who spent much of their time in space suits.

Probably the one biggest mistake, of course, was made when he walked silently to the numbered locker his uncle had told him would contain his suit, and pulled it out. He donned it quickly and correctly under the attendant's eyeand who, Jim Talles. asked the world later, would have foreseen that the earlier training session thus would turn out to be a mistake?

If Rick had been slow or clumsy, if Pierre Montaux had had the slightest grounds for suspecting Rick Suspee never before had ventured into vacuum … But there was nothing to warn Pierre. The suit went on smoothly. It fitted correctly. Rick attached helmet and gauntlets properly, did the proper things to seal them. He made the proper signals to request tightness check, said the right things over the radio for the communications check. He strode over to the inner lock door, deftly operated the cycling switch, and waited until the inner light flashed green before opening the portal. There was nothing to show that he had not done it all a score, even a hundred, times before.

Montaux let him through, checked the manual seal on the inside after the door closed, and gestured a "proceed" through the transparent wall. The outer door's light was now green. Rick operated its plainly labeled opening switch, went through, closed it, and disappeared from the sight of Pierre Montaux. And, for many hours, from the sight of mankind.

From MISTAKEN FOR GRANTED by Hal Clement (1974)

      UN Marines were charging the Martian outpost. The yearlong cold war was going hot. Somewhere deep behind the cool mental habits of training and discipline, she was surprised. She hadn’t really thought this day would come.
     The rest of her platoon were out of the outpost and arranged in a firing line facing the UN position. Someone had driven Yojimbo out onto the line, and the four-meter-tall combat mech towered over the other marines, looking like a headless giant in power armor, its massive cannon moving slowly as it tracked the incoming Earth troops. The UN soldiers were covering the 2,500 meters between the two outposts at a dead run.
     Why isn't anyone talking? she wondered. The silence coming from her platoon was eerie.
     And then, just as her squad got to the firing line, her suit squealed a jamming warning at her. The top-down vanished as she lost contact with the satellite. Her team’s life signs and equipment status reports went dead as her link to their suits was cut off. The faint static of the open comm channel disappeared, leaving an even more unsettling silence.
     She used hand motions to place her team at the right flank, then moved up the line to find Lieutenant Givens, her CO. She spotted his suit right at the center of the line, standing almost directly under Yojimbo. She ran up and placed her helmet against his.
     "What the f**k is going on, El Tee?" she shouted.
     He gave her an irritated look and yelled, “Your guess is as good as mine. We can’t tell them to back off because of the jamming, and visual warnings are being ignored. Before the radio cut out, I got authorization to fire if they come within half a klick of our position."

From CALIBAN'S WAR by "James S.A. Corey" 2012. Second novel of The Expanse

He gave a start as a pair of mittened paws grasped his upper arms and a helmet clinked against his. He found himself staring into the raw red features of the U.S. repair-crew foreman, a likable, plain-spoken man named Grogan. Grogan was being smart enough not to use his suit radio (because this is a joint US-Chinese expedition, the two nations are at "cold-war" status, and the place is swarming with security agents from both nations).

“Beg pardon, sir,” Grogan said, “but what’s going on? We saw the landing leg spring loose through the telescope, but that’s all.”

Jameson pressed his helmet against the other man’s. “Tell you all about it later. For now, just make sure that everything you replace in the locking mechanism is all right. Particularly the bolts.”

From THE JUPITER THEFT by Donald Moffitt (1977)

     In the 1970s, sawmill workers could talk about technical matters or insult each other in their own special sign language.
     When the linguists Martin Meissner and Stuart Philpott first started visiting sawmills in British Columbia in the 1970s, they thought they’d find workers communicating without speaking, probably with some simple gestures that contained technical information. There was a long history of such communication in the face of extreme noise: For centuries, American mill workers had used systems of hand signals to tell each other, across the unending roar of the saws, how to cut wood.
     What they discovered, though, floored them. The researchers witnessed a sign language system complete enough that workers could call each other “you crazy old farmer,” tell a colleague that he was “full of crap,” or tell each other when the foreman was “f*****g around over there.”
     Outside of deaf communities, hearing people sometimes develop what are now often called “alternate sign languages” to communicate when words will not do. In monasteries, monks uses signs to communicate in areas where speech is forbidden, for instance. In industries where machines made speaking impossible—in ships’ engine rooms, in steel mills, textile mills, and sawmills—workers also found ways to communicate with their hands.
     In 1955, when Popular Mechanics covered these industrial sign languages, many were already disappearing. But in the 1970s, Meissner and Philpott found a sign language still used in sawmills. Their research further honed in on the culture of one particular mill where workers had developed a system of 157 signs that they used not just to communicate about their work but to trade small talk, tell crude jokes and tease each other.
     The linguist were struck by the language’s “ingenuity and elegance,” they wrote. It was also a secret hidden in plain sight: the mill workers’ bosses, it seems, had almost no idea what they were saying.
     The core of the sawmill workers’ sign language was a system of numbers, standardized across the industry. Those signs were shared in a technical notebook, and, the linguists wrote,”in the view of the management, that was about all there was to the language.” But it covered much more ground than technical communication. Workers could talk about quitting time, lunch time, and cigarette breaks. They could talk about sports and the bets they placed on games. They could talk about their wives, cars, and colleagues. They could tell jokes and comment on what was going on around them without their bosses ever knowing.

     Compared to a fully developed sign language, which can have thousands of signs, this one was limited in its scope. It did provide these men with a way to cover the basic grounds of collegial small talk, and in at least one case, sawmill sign language also worked in the home. A couple of years after Meissner and Philpott published their research on British Columbia’s mills, another linguist, Robert Johnson, found a retired sawmill worker in Oregon who had lost his hearing and used a variant on sawmill sign language to communicate with his wife and son, who was also deaf. About three-quarters of their corpus of 250 signs overlapped with the British Columbia sawmill signs Meissner and Philpott had collected. There was also significant overlap with American Sign Language.

Hull Sealant


Betty responded smoothly to the control; he let her drift outward for a hundred feet, then checked her forward momentum and spun her round so that he was looking back at the ship. Then he began his tour of the pressure hull.

His first target was a fused area about half an inch across, with a tiny central crater. The particle of dust that had impacted here at over a hundred thousand miles an hour was certainly smaller than a pinhead, and its enormous kinetic energy had vaporized it instantly. As was often the case, the crater looked as if it had been caused by an explosion from inside the ship; at these velocities, materials behaved in strange ways and the laws of common-sense mechanics seldom applied.

Poole examined the area carefully, then sprayed it with sealant from a pressurized container in the pod's general-purpose kit. The white, rubbery fluid spread over the metal skin, hiding the crater from view. The leak blew one large bubble, which burst when it was about six inches across, then a much smaller one, then it subsided as the fast-setting cement did its work. He watched it intently for several minutes, but there was no further sign of activity. However, to make doubly certain, he sprayed on a second layer; then he set off toward the antenna.

From 2001 A SPACE ODYSSEY by Arthur C. Clarke (1968)

      He waved a mechanic over to him. “Mr. Syaloch would like you to explain your outfit,” he said with ponderous sarcasm.
     “Sure. Regular spacesuit here, reinforced at the seams.” The gauntleted hands moved about, pointing. “Heating coils powered from this capacitance battery. Ten-hour air supply in the tanks. These buckles, you snap your tools into them, so they won’t drift around in free fall. This little can at my belt holds paint that I spray out through this nozzle.”
     “Why must spaceships be painted?” asked Syaloch. “There is nothing to corrode the metal.”
     “Well, sir, we just call it paint. It’s really gunk, to seal any leaks in the hull till we can install a new plate, or to mark any other kind of damage. Meteor punctures and so on.” The mechanic pressed a trigger and a thin, almost invisible stream jetted out, solidifying as it hit the ground.
     “But it cannot readily be seen, can it?” objected the Martian. “I, at least, find it difficult to see clearly in airlessness.”
     “That’s right, Light doesn’t diffuse, so…well, anyhow, the stuff is radioactive—not enough to be dangerous, just enough so that the repair crew can spot the place with a Geiger counter.
     “I understand. What is the half-life?”
     “Oh, I’m not sure. Six months, maybe? It’s supposed to remain detectable for a year.”

From THE MARTIAN CROWN JEWELS by Poul Anderson (1958)


RocketCat sez

This, space cadets, is a Radar Gun. Don't roll your eyes at this thing, newbie, I know whatcha thinking and you're dead wrong. Emphasis on "dead."

You think you're some kind of Lensman Kimball Kinnison with a "Look of Eagles" who don't need no stupid kindergarten training-wheels radar gun to tell your closing rate. You think you can just eyeball it.

You also think you're actually going to survive longer than five minutes in your first EVA because you are a clueless newbie with delusions of competence. Do a search in InterPlaNetPedia for the Dunning-Kruger effect and you'll see a picture of you.

Just ask Vasily Tsibliyev.

On 25 June 1997 those bean-counting morons at Roscosmos thought they could save a few rubles by eliminating the Kurs automated docking system and instead do it manually. When the Soviet Union disintegrated in 1991 the Kurs network became the property of the Ukraine, who immediately started price-gouging Roscosmos. So the bean counters figured to heck with the Ukraine, who needs that fancy-smancy Kurs anyway? Our boys in Roscosmos have the Look of Eagles, they can just eyeball it. For free.

Poor Vasily got stuck with the honor of being the first to try it. He was tasked with the job of sitting in the Mir space station and trying to dock the Progress M-34 by remote control. By eyeball, with no Kurs automated docking system for help.

What a smash up!

Vasily couldn't even begin to tell by eye the distance or closing rate. When he suddenly realized that the Progress was up to ramming speed, he floored the braking rockets, but it was too late. Progress clobbered a solar panel then plowed into Mir's Spektr module. It ruined the solar panel, crumpled a radiator, and punched a hole in Spektr’s hull which immediately started spewing vital breathing mix into the depths of space. Oh, and it put the entire station into a tail spin as well, because the ruined solar panel was the one powering the gyros which ordinarily prevented just such an occurrence. The spin made the remaining solar panels not facing the sun anymore, so now there was no solar power at all.

The cosmonauts managed to radio ground control enough info on the station's spin so it could be stopped, which is the only reason they didn't all die. That and their frantic efforts to plug the air leak.

After all the finger pointing and recriminations had died down a bit, Roscosmos did some ground simulations with five veteran cosmonauts to see if the concept would work in theory. Because they really hated being gouged by the Ukraine. And the bean counters really wanted to deflect the blame aimed at them so it would land on poor Vasily.

Unfortunately for the bean-counters, all five cosmonauts crashed their ships in the ground simulators. Now the bean-counters faced awkward questions about "why the flaming frak didn't you idiots try ground simulations first before you tried it live?"

The point is, you newbie, the human eye was not built to judge ranges and closing rates in airless space. It is used to judging distance by how the dusty air obscures things with distance. AND IF YOU HAVEN'T FIGURED IT OUT BY NOW THERE AIN'T NO FREAKING AIR IN SPACE!

Just be sure you have your last will and testament on file at the front office.

Astronauts may also need a "beeper". This is a low powered radar used to locate small objects nearby (like that zero-recoil wrench you let go of "just for a minute" which seems to have run away). You wave it around until is starts beeping (heard over your suit radio). As you approach the object the beep rate increases.

If you are doing space construction work or asteroid mining, you'll need a radar range-and-rate gun. This is similar to the radar guns the highway patrol uses to catch speeders, but it also tells the range. It gives you the precise distance to the object and the current closing rate between you and the object, using radar for range and doppler radar for closing rate.

This is important because it is almost impossible to tell the range to an object by eye in space. And even more impossible to tell how fast it is approaching or receding from you. This is a standard instrument on spacecraft and space taxis but not on a space suit.


'I'll borrow a Beeper from Stores,' replied Peter. 'Joe Evans will let me sign for one.'

A Beeper, I should explain, is a tiny radar set, not much bigger than a hand-torch, which is used to locate objects that have drifted away from the Station. It's got a range of a few miles on anything as large as a space-suit, and could pick up a ship a lot farther away. You wave it around in space and when its beam hits anything you hear a series of 'Beeps'. The closer you get to the reflecting object, the faster the beeps come, and with a little practice you can judge distances pretty accurately.

From ISLANDS IN THE SKY by Arthur C. Clarke (1952)

(ed note: Coyote Westlake is in a small habitat module attached to the asteroid RA45, with her ship the Vegas Girl parked nearby. When she wakes up, she is startled to discover that the Vegas Girl is now far away from the asteroid.)

How the hell could this have happened? She had left the Vegas Girl in a perfectly matched orbit relative to RA45. There was no way she could have drifted that far while Coyote was asleep.

Unless she had been sleeping for one hell of a long time. She checked her watch and compared it to the time display on the hab shed’s chronometer. She even checked the date, just to be sure she hadn’t slept around the clock. But no, she had been out only a few hours. How far had her ship drifted?

Coyote grabbed the radar range-and-rate gun out of its rack and aimed it through the spaceward viewport, lining up the sights on the Girl. It was a low-power portable unit, not really meant to work at long range. Normally she used it to establish distance from and velocity toward an asteroid, but it could track her ship just as handily. She got the blinking strobe in the sights and pulled the trigger.

The gun pinged cheerfully twice to indicate it had gotten a good range and rate on its target. Coyote checked the gun’s tracking data display.

And her heart nearly stopped. The Vegas Girl was over one hundred kilometers astern, and the ship was moving away at over three hundred meters a second.

But wait a moment. The tracker just showed relative velocity, not which object was doing the moving. She peered out the port again, and spotted the triple-blink beacon she had left on RA46, the last rock she had worked. She swore silently. RA46 was in the wrong part of the sky. She fired a ranging pulse at it and got back virtually the same velocity value. The Girl was stationary relative to RA46. So it wasn’t the ship moving. It was this rock.

From THE RING OF CHARON by Roger MacBride Allen (1990)

spotter (n.): An ancient spacer’s tool, dating back almost as far as the navigator’s sextant, the engineer’s multi, or the medtech’s hand effector, used for locating and profiling distant objects in space: a boon to anyone who has to manage a docking bay, shift cargo in microgravity, perform extravehicular activities in crowded neighborhoods, or engage in the smallest of small-craft operations, which is to say, riding a candle.

The original spotters were no more than handheld radar transceivers with direct audio feedback into the user’s helmet interface. Wave it around, and when you hear beeping, it’s pointing at something. The faster the beeping, the closer that something is to you. Learning what a particular rate meant in terms of range, and keeping an ear on the change of beep rate, were left as skills for the user to develop.

The modern spotter is a rather more sophisticated device, thanks to miniaturization and commercial development. HUD feedback now monitors its position relative to your body to provide a more accurate sense of direction, and even the most basic models provide precise range and closing rate information. More advanced models use a phased-array antenna to sweep the beam across a target once detected, providing a profile for target recognition purposes and an estimate of spin.

Of course, there is in theory very little use for a spotter in the current age of space, since all spacecraft from the largest to the smallest include a transponder, and are further constructed from LOP-compliant hardware which will obligingly disclose its location upon receiving a network request. The Grand Survey has detailed charts of every object in space larger than a child’s ball. All objects within range should therefore, says theory, already be highlighted on your HUD.

It is a sign of the tremendous respect that spacer culture has for theory that there are at least a brace of spotters stored in every airlock and docking bay from the Core to the Rim.

– A Star Traveler’s Dictionary

From PING by Alistair Young (2016)

Signal Flare

A flare is a chemical pyrotechnic that produces a brilliant light without an explosion. As spacesuit gear, they would probably be for purposes of emergency illumination or as a maritime distress signal.


The calculator in his head proceeded with its business. Of those American vessels near the Argonne when first contact was made with the enemy, only the Washington was sufficiently massive to go out in a blast of yonder size and shape. If that was the case Captain Martin Diaz of the United States Astromilitary Corps was a dead man. The other ships of the line were too distant, traveling on vectors too unlike his own, for their scout boats to come anywhere close. On the other hand, it might well have been a Unasian battlewagon. Diaz had small information on the dispositions of the enemy fleet. He’d had his brain full just directing the torp launchers under his immediate command. If that had indeed been a hostile dreadnaught that got clobbered, surely none but the Washington could have delivered the blow, and its boats would be near—


For half a second Diaz was too stiffened by the sight to react. The boat ran black across waning clouds, accelerating on a streak of its own fire. The wings and sharp shape that were needed in atmosphere made him think of a marlin he had once hooked off Florida, blue lightning under the sun—Then a flare was in his hand, he squeezed the igniter and radiance blossomed.

Just an attention-getting device, he thought, and laughed unevenly as he and Bernie Sternthal had done, acting out the standard irreverences of high school students toward the psych course. But Bernie had left his bones on Ganymede, three years ago, and in this hour Diaz’s throat was constricted and his nostrils full of his own stench. He skyhooked the flare and hunkered in its harsh illumination by his radio transmitter. Clumsy in their gauntlets, his fingers adjusted controls, set the revolving beams on SOS. If he had been noticed, and if it was physically possible to make the velocity changes required, a boat would come for him. The Corps looked after its own.

Presently the flare guttered out. The pyre cloud faded to nothing. The raft deck was between Diaz and the shrunken sun. But the stars that crowded on every side gave ample soft light. He allowed his gullet, which felt like sandpaper, a suck from his one water flask. Otherwise he had several air bottles, an oxygen reclaim unit, and a ridiculously large box of Q rations. His raft was a section of inner plating, torn off when the Argonne encountered the ball storm. She was only a pursuit cruiser, unarmored against such weapons. At thirty miles per second, relative (260 Ricks! Each 1kg ball does 50% the damage of a Tomahawk cruise missile), the little steel spheres tossed in her path by some Unasian gun had not left much but junk and corpses. Diaz had found no other survivors. He’d lashed what he could salvage onto this raft, including a shaped torp charge that rocketed him clear of the ruins. This far spaceward he didn’t need screen fields against solar particle radiation. So he had had a small hope of rescue. Maybe bigger than small, now.

Unless an enemy craft spotted him first. His scalp crawled with that thought. His right arm, where the thing he might use in the event of capture lay buried, began to itch (he has an implanted isotopal explosive device, to be detonated when taken aboard a hostile ship). But no, he told himself, don’t be sillier than regulations require. That scoutboat was positively American. The probability of a hostile vessel being in detection range of his flare and radio—or able to change vectors fast enough—or giving a damn about him in any event—approached so close to zero as made no difference.

From KINGS WHO DIE by Poul Anderson (1962)

Cherry Picker

Sometimes astronauts have to repair or service items that are not directly connected to their spacecraft. Breaking contact with the ship is possible by using an MMU, but is always risky. A useful compromise is using the cherry picker concept, having the astronaut's feet attached to a aerial work platform based on the spacecraft, and the platform's arm maneuvers to position the astronaut.

On the International Space Station, this is done with the amazing Canadarm2 (successor to the original Canadarm).

Suit Into Ship

As one adds more gadgets and attachments to a space suit, it gradually morphs into a tiny spaceship. It starts with spring-loaded broomsticks and picks up speed with the addition of tiny attitude jets and maneuvering rockets. As a parallel development, a rocket engine with a skeletal frame to hold astronauts is the first "space taxi". When a space suit is massive enough that one climbs into it instead of putting it on like clothing, equipped with mechanical arms and waldoes, you suddenly have a space pod. Then if the pod grows to the size of a baby spaceship, but with massive over-sized engines, you finally have a space tug.


A broomstick is a spring loaded gizmo used by astronauts to launch themselves from place to place, and to bring themselves to a stop upon arrival.

... This was where the broomsticks came in.

Commander Doyle had invented them, and the name, of course, came from the old idea that once upon a time witches used to ride on broomsticks. We certainly rode around the station on ours. They consisted of one hollow tube, sliding inside another. The two were connected by a powerful spring, one tube ending in a hook, the other in a wide rubber pad. That was all there was to it. If you wanted to move, you put the pad against the nearest wall and shoved. The recoil launched you into space, and when you arrived at your destination you let the spring absorb your velocity and bring you to rest. Trying to stop yourself with your bare hands was liable to result in sprained wrists.

It wasn't quite as easy as it sounds, though, for if you weren't careful you could bounce right back the way you'd come.

From ISLANDS IN THE SKY by Arthur C. Clarke (1952)

There are some professions which have evolved unique and characteristic tools — the longshoreman's hook, the potter's wheel, the bricklayer's trowel, the geologist's hammer. The men who had to spend much of their time on zero-gravity construction projects had developed the broomstick.

It was very simple — a hollow tube just a metre long, with a footpad at one end and a retaining loop at the other. At the touch of a button, it could telescope out to five or six times its normal length, and the internal shock-absorbing system allowed a skilled operator to perform the most amazing manoeuvres. The footpad could also become a claw or hook if necessary; there were many other refinements, but that was the basic design. It looked deceptively easy to use; it wasn't.

Everything happened in about five seconds. Brailovsky triggered his broomstick, so that it telescoped out to its full length of four metres and made contact with the approaching ship. The broomstick started to collapse, its internal spring absorbing Brailovsky's considerable momentum; but it did not, as Curnow had fully expected, bring him to rest beside the antenna mount. It immediately expanded again, reversing the Russian's velocity so that he was, in effect, reflected away from Discovery just as rapidly as he had approached. He flashed past Curnow, heading out into space again, only a few centimetres away. The startled American just had time to glimpse a large grin before Brailovsky shot past him.

A second later, there was a jerk on the line connecting them, and a quick surge of deceleration as they shared momentum. Their opposing velocities had been neatly cancelled; they were virtually at rest with respect to Discovery. Curnow had merely to reach out to the nearest handhold, and drag them both in.

From 2010: Odyssey Two by Arthur C. Clarke, 1982.

Rocket Pack

While engaging in extra-vehicular activity, our space-suited rocketeers may use a "broomstick", or some kind of small jets (a Manned Maneuvering Unit or MMU). NASA has also developed a nitrogen-gas propelled unit that fits on the backpack, called the Simplified Aid for Extravehicular Activity Rescue (SAFER). The SAFER can help an astronaut return to the shuttle or station in the event that they gets separated from the spacecraft. SAFER has a deltaV capacity of 3 m/s.

Space Cadet by Robert Heinlein (1948)
The training rocket packs have 15 m/s of delta V for a space-suited astronaut of 136 kilograms of mass (standard rocket packs have more).
Destination Moon (1950)
The crew used an industrial tank of oxygen as an impromptu thruster to rescue one of the astronauts who foolishly allowed both of his magnetic boots to detach from the ship's hull.
Lucky Starr and the Pirates of the Asteroids by Issac Asimov (1953)
Astronauts used push-units: a torus-shaped pressurized tank of carbon dioxide around the astronaut's waist, connected by tube to the L-shaped push gun.
Revolt on Alpha C by Robert Silverberg (1955)
Astronauts carried a slugthowing pistol with four bullets as a hand-held maneuvering unit. In reality this is not very efficient. A .45 automatic will give a 68 kg person about 0.088 m/s deltaV per bullet, closer to 0.044 m/s if the person+spacesuit mass is 136 kg.
Comic Book Space 1999 No 6 (1976)
Commander Koenig uses his space suit's oxygen tanks as emergency maneuvering jets to retrieve the space helmet before he suffocates.
2010 The Year We Make Contact (1984)
They retained Brailovsky's shared momentum trick from the novel, but replaced the broomstick with a thruster pack. The broomstick automatically retains the exact velocity, with a thruster you have to be sure to do a precise burn of the same magnitude in the opposite direction.


     "The trick to jetting yourself in space,"—he went on, 'lies in balancing your body on the jet—the thrust has to pass through your center of gravity. If you miss and don't correct it quickly, you start to spin, waste your fuel, and have the devil's own time stopping your spin. "It's no harder than balancing a walking stick on your finger—but the first time you try it, it seems hard.
     "Rig out your sight." He touched a stud at his belt; a light metal gadget snapped up in front of his helmet so that a small metal ring was about a yard in front of his face. "Pick out a bright star, or a target of any sort, lined up in the direction you want to go. Then take the ready position— no, no! Not yet—I'll take it."
     He squatted down, lifted himself on his hands, and very cautiously broke his boots loose from the side, then steadied himself on a cadet within reach. He turned and stretched out, so that he floated with his back to the ship, arms and legs extended. His rocket jet stuck straight back at the ship from the small of his back; his sight stuck out from his helmet in the opposite direction.
     He went on, "Have the firing switch ready in your right hand. Now, have you fellows ever seen a pair of adagio dancers? You know what I mean—a man wears a piece of leopard skin and a girl wearing less than that and they go leaping around the stage, with him catching her?"
     Several voices answered yes. Hanako continued, "Then you know what I'm talking about. There's one stunt they always do—the girl jumps and the man pushes her up and balances her overhead on one hand. He has his hand at the small of her back and she lays there, artistic-like. "That's exactly the way you got to ride a jet. The push comes at the small of your back and you balance on it. Only you have to do the balancing—if the push doesn't pass exactly through your center of gravity, you'll start to turn. You can see yourself starting to turn by watching through your sight. "You have to correct it before it gets away from you. You do this by shifting your center of gravity. Drag in the arm or leg on the side toward which you've started to turn. The trick is—"

     "Just a second, Sarge," someone cut in, "you said that just backwards. You mean; haul in the arm or leg on the other side, don't you?"
     "Who's talking?"
     "Lathrop, number six. Sorry."
     "I meant what I said, Mr. Lathrop."
     "Go ahead, do it your way. The rest of the class will do it my way. Let's not waste time. Any questions? Okay, stand clear of my jet."

     The half circle backed away until stopped by the anchored static lines. A bright orange flame burst from the sergeant's back and he moved straight out or "up," slowly at first, then with increasing speed. His microphone was open; Matt could hear, by radio only, the muted rush of his jet—and could hear the sergeant counting seconds: "And … one! … and … two! … and … three!" With the count of ten, the jet and the counting stopped.
     Their instructor was fifty feet "above" them and moving away, back toward them. He continued to lecture. "No matter how perfectly you've balanced you'll end up with a small amount of spin. When you want to change direction, double up in a ball—" He did so. "—to spin faster—and snap out of it when you've turned as far as you want." He suddenly flattened out and was facing them. "Cut in your jet and balance on it to straighten out on your new course—before you drift past the direction you want."
     He did not cut in his jet, but continued to talk, while moving away from them and slowly turning. "There is always some way to squirm around on your axis of rotation so that you can face the way you need to face for a split second at least. For example, if I wanted to head toward the Station—" Terra Station was almost a right angle away from his course; he went through contortions appropriate to a monkey dying in convulsions and again snapped out in starfish spread, facing the Station—but turning slow cartwheels now, his axis of rotation unchanged.
     "But I don't want to go to the Station; I want to come back to the ship." The monkey died again; when the convulsions ceased, the sergeant was facing them. He cut in his jet and again counted ten seconds. He hung in space, motionless with respect to the ship and his class and about a quarter mile away. "I'm coming in on a jet landing, to save time." The jet blasted for twenty seconds and died; he moved toward them rapidly.
     When he was still a couple of hundred feet away, he flipped over and blasted away from the ship for ten seconds. The sum of his maneuvers was to leave him fifty feet away and approaching at ten feet per second. He curled up in a ball again and came out of it feet toward the ship.

     Five seconds later his boots clicked to steel and he let himself collapse without rebound. "But that is not the way you'll do it," he went on. "My tanks hold more juice than yours do—you've got fifty seconds of power, with each second good for a change of speed on one foot-second—that's for three hundred pounds of mass (15 m/s of delta V for 136 kilograms of mass); some of you skinny guys will go a little faster.
     "Here's your flight plan: ten seconds out, counted. Turn as quick as you can and blast fifteen seconds back. That means you'll click on with five foot-seconds (10 seconds outward. Turn. 15 seconds will kill the 10 seconds outward, and give a net of 5 seconds inward). Even your crippled grandmother ought to be able to do that without bouncing off. Lathrop! Unhook—you're first."

     As the cadet came up, Hanako anchored himself to the ship with two short lines and took from his belt a very long line. He snapped one end to a hook in the front of the cadet's belt and the other to his own suit. The student looked at it with distaste. "Is the sky hook necessary?"
     Sergeant Hanako stared at him. "Sorry, Commodore—regulations. And shut up. Take the ready position."
     Silently the cadet crouched, then he was moving away, a fiery brush growing out of his back. He moved fairly straight at first, then started to turn.
     He pulled in a leg—and turned completely over.
     "Lathrop—cut off your jet!" snapped Hanako. The flame died out, but the figure in the suit continued to turn and to recede. Hanako paid out his safety line. "Got a big fish here, boys," he said cheerfully. "What do you think he'll weigh?" He tugged on the line, which caused Lathrop to spin the other way, as the line had wound itself around him. When the line was free he hauled the cadet in.
     Lathrop clicked on. "You were right, sergeant. I want to try it again—your way."
     "Sorry. The book says a hundred per cent reserve fuel for this drill; you'd have to recharge." Hanako hesitated. "Sign up for tomorrow morning—I'll take you as an extra."
     "Oh—thanks, Sarge!"
     "Don't mention it. Number one!"

From SPACE CADET by Robert Heinlein (1948)
SPACE 1999 NUM 6

(Click for larger images)

     Koenig's space suit protects him from the worst of the terrible heat and radiation. But the shock of the blast is another matter… Unable to brace himself, Koenig is hurled with stunning force against a bulkhead…

     Not enough to render him fully unconscious, the blow nevertheless leaves him too dazed to properly react to the situation… He has barely the wits about him to grab at a door-frame as the explosive decompression sucks every loose object into the void…

     But, his gloves were not designed for such a grip… The hurricane winds continue to push relentlessly against him…

     Until…His grip fails…

     And John Koenig, Commander of Moonbase Alpha, upon whose survival must ultimately depend the lives of 300 men and women… Is hurled into the airless maw of space…
     There is no sound in space — no scents. Only the numbing cold of the emptiness between the stars…

     At least, this close to a star, Koenig has the small relief of knowing there is enough heat to keep the moisture on his eye from freezing…

     He will not be blind for the rest of his life…

     Although that is a span which can now be meaured in seconds…

     9: A helmet!
     By coincidence, Koenig's own, though any helmet would do—
     If he can reach it, that is…
     And he has already wasted six precious seconds… (Actually time to unconsciousness is more like 10 seconds, not 15. But close enough.)

     8: Falling through space at 100 thousand miles an hour: a dying man, and a slim hope of survival—
     But the force of his expulsion has set Koenig tumbling…

     7: He twists, trying to angle himself for a desperate ploy…
     Knowing that too great a twist will only set him spinning…

     6: Eyes locked on the helment, Koenig finds the control circuit on his wrist by touch…
     Already his fingers are growing numb, his lungs aching…

     5: Now!
     Koenig opens the valve on his left-hand air tank…
     Precious oxygen spews into the void… But Newton's law holds true: "For every action, there is an equal and opposite reaction…"

     4: Koenig moves!
     Slowly…painfully slowly…but he moves!!
     But his improvised thruster is off-center… He begins to twist away from his target…

     3: Joints pop as Koenig strains towards the helmet…
     He will have only one chance…

     2: Got it!
     His skin is drumhead taut…
     Already his extermities are turning purple…

     1: Stay calm!
     Helmet in place…

     0: Connect hose…

From SPACE 1999 No 6 by Nicola Cuti, artwork by John Byrne (1976)

Jim's job turned out to be running a small welder that operated on compressed oxygen and acetylene. "Youll be working on some tricky alloys," Bart told him. "Keep the oxygen supply a little under what you need for the best burning. And before you turn it on, get a good grip. It's a small rocket, and don't forget that!"

They filed out. Some of the men seemed to be fully at home already, and simply dived off into space, kicking themselves toward the work. They carried tiny rocket tubes which could be used to kick themselves back in case they misjudged, but it wasn't something Jim cared to try yet. He was glad to see that others pulled themselves along the girders hand over hand.

Everything seemed to be done by hand power. Men were moving out to the piles of material scattered about, sorting them, and attaching cords before pulling them back by hand. There was no weight, but the inertia of the objects sometimes required the power of several men to overcome it. Once in motion, anything tended to keep that motion, and jockeying the parts into place and holding them there was a tricky business.

The welding proceeded well enough, however. Out here without air, the metals could never tarnish. They were given a brightening before being assembled to remove any corrosion from Earth's atmosphere, and then remained bright until they would be welded. Even aluminum and the titanium alloys were manageable.

Bart came over after a few minutes and inspected his work. "Good enough. But don't sit facing the same way so long. That Sun's hotter than you think. Sit too long in one direction and you'll heat one side of your suit near melting, while the other side freezes stiff. How do you feel?"

Jim had almost stopped thinking about that, under the pressure of the work. A boy who'd collapsed on the previous shift had put the welding behind the assembly, and Jim was driving himself to catch up. Bart clapped him on the shoulder and started to move on. Then he swung back.

"Jim, don't ever let me find you with your belt unfastened on the job again!" He snapped the silicone-plastic strap around the girder and to a hook in the suit. "I told you that torch was a small rocket! Let go, and you'll sail out like a bird if you're not strapped down."

"I guess I forgot this time," Jim admitted. "Sorry, Bart!"

The welding went on for several hours, until he finished what was ready. Part of the time, he'd been within reach by radio of one of the young college boys, and had struck up a conversation, forcing himself to stop being a lone wolf. He'd found that there was a sound reason for using the oxyacetylene welder instead of an electric rig. The compressed gases were lighter than batteries, and the station was still underpowered. They'd put up a sun mirror out of sheets of station walls and had used sections of pipe to make a boiler where the heat converged. It was driving a small steam plant and generator, but there were only about ten kilowatts to power the whole station until they could get the main power plant going much later.

The work went on more easily in the following days. New men came up from Earth, and most of them went back. One of them did almost the same thing Jim had done, but turned his rocket tube on while it was still pointing toward his helmet. Nobody got much work done that day, and there was no conversation at dinner.

From STEP TO THE STARS by Lester Del Rey. 1954


Many early designs of spacesuits for use in free fall were lacking legs. This simplifies the design. This gradually becomes a hard suit which allows an astronaut to work in a pressurized environment and so avoid the bends.


One day, two weeks after he’d arrived, he decrypted a message with some surprising news. The boss was coming. As in, Sean Probst, the founder and CEO of Arjuna Expeditions.
     “How can that even happen?” Dinah asked. “How can anyone just come up to Izzy? (International Space Station) Don’t you need a launch vehicle? A spacecraft? A place to dock it? Permission?!”

     These were largely rhetorical questions. Sean had made seven billion dollars from an Internet startup before throwing his energies into asteroid mining. Along the way he’d sunk a billion or two into other private space startups. (perhaps the character was inspired by Elon Musk)

     “He’s coming up alone,” Larz said, “in a Drop Top.”
     It took Dinah a moment, and a quick Google search, to access the memory. Also referred to as “the Convertible,” the Drop Top was one of the more creative recent approaches to space tourism. It was based on the idea that what tourists really wanted to experience was the direct view of the Earth, the stars, and (until it had ceased to exist) the moon. Conventional space capsules had tiny windows. What you really wanted to do was stick your head into a transparent bubble so that you could enjoy a clear view out in all directions. In other words, you wanted to be in a space suit, basically floating free in space. The Drop Top was a small, simple capsule, capable of carrying four astronauts, dressed in custom-made space suits with bubble helmets. During the ascent through the atmosphere, and the reentry, they were protected by a sturdy aeroshell. But while they were orbiting the Earth, the shell retracted, like the roof of a convertible, exposing them completely to space, and even giving them some freedom to spacewalk. (much like the one-man spacecraft from Copenhagen Suborbitals)
     “I don’t think a Drop Top can reach an orbit this high, can it?” Dinah asked.
     “Sean’s coming up alone. It is some kind of special one-passenger model—the extra mass is being used for propellant.”
     “And then what? He just goes to an airlock and knocks on the door?”
     “Basically, yes,” Larz said. “What will they do? Tell him to go away?”

     His arrival at the space station had been unconventional, and roundabout. There was no docking station to accommodate the Drop Top. There couldn’t possibly be, since the Drop Top didn’t even have a port or an airlock. So there’d been no way to attach it to Izzy. He had brought the little convertible in under manual control, tapping the thrusters one at a time, spitting bullets of spent propellant into space, then pausing for one, five, or ten minutes to ponder the consequences. Space nerd that he was, he knew perfectly well that orbital mechanics did not obey the rules of earthbound physics. He had enough humility, and enough spare oxygen, to take it slow. Eventually he had drifted close enough to Amalthea that a three-Siwi train with a Grabb on its head had been able to reach out and grapple a fitting on the edge of his cockpit. He had then ejected himself from the vehicle, floating free in space, and gone on a little tour of inspection, firing off occasional messages to Dinah so that she could know where he was. Since there was no direct radio connection, these had to be relayed through a server in Seattle.

     He was in a tubesuit: a tourist product that in some ways was less capable, in others more so, than the government-issue ones used by cosmonauts and astronauts. It had no legs at all, since legs were pretty useless in space. It looked like a test tube with a pair of arms and a bubble-shaped dome on the top. The arms had shoulder and elbow joints, but no hands as such. Gloves were notoriously the most troublesome parts of space suits. Instead, the tubesuit’s arms terminated in rounded-off stumps. Projecting from each of these was a skeletal hand consisting of a thumb and three fingers, actuated by steel cables that ran through airtight fittings into the arm-stumps. The occupant could slip his hand into a glovelike contraption inside the stump that would pull on the metal tendons as he moved his fingers, thereby actuating the external digits and enabling him to grab things and perform a few simple operations. There was nothing about it that couldn’t have been built by a tinkerer in an inventor’s lab in 1890, or 1690 for that matter. People who had used them reported that they worked surprisingly well—better in some ways than conventional space suit gloves, which were stiff and fatigued the hands.
     There was plenty of extra room inside the stumps, and so when not using the clawlike hands he could pull his fingers free of the internal glove and let them rest on internal touchpads and joysticks where he could type and swipe to his heart’s content. The suit had some tiny thrusters that enabled the user to “fly” it around. Sean had put these to work at some length, wandering around the outside of Izzy and inspecting the work of the robots, the modifications made to the truss, and other curiosities. Finally he had found his way to an airlock at the aft end of H2, where Dinah had let him in.

From SEVENEVES by Neal Stephenson (2015)

At this point, perhaps I should remind you that the suits we use on the station are completely different from the flexible affairs men wear when they want to walk around on the Moon. Ours are really baby space ships, just big enough to hold one man. They are stubby cylinders, about seven feet long, fitted with low-powered propulsion jets, and have a pair of accordion-like sleeves at the upper end for the operator's arms.

As soon as I'd settled down inside my very exclusive space craft, I switched on power and checked the gauges on the tiny instrument panel. All my needles were well in the safety zone, so I gave Tommy a wink for luck, lowered the transparent hemisphere over my head and sealed myself in. For a short trip like this, I did not bother to check the suit's internal lockers, which were used to carry food and special equipment for extended missions.

As the conveyor belt decanted me into the air lock, I felt like an Indian papoose being carried along on its mother's back. Then the pumps brought the pressure down to zero, the outer door opened, and the last traces of air swept me out into the stars, turning very slowly head over heels.

The station was only a dozen feet away, yet I was now an independent planet—a little world of my own. I was sealed up in a tiny, mobile cylinder, with a superb view of the entire universe, but I had practically no freedom of movement inside the suit. The padded seat and safety belts prevented me from turning around, though I could reach all the controls and lockers with my hands or feet.

In space the great enemy is the Sun, which can blast you to blindness in seconds. Very cautiously, I opened up the dark filters on the "night" side of my suit, and turned my head to look out at the stars. At the same time I switched the helmet's external sunshade to automatic, so that whichever way the suit gyrated my eyes would be shielded.

Presently, I found my target—a bright fleck of silver whose metallic glint distinguished it clearly from the surrounding stars. I stamped on the jet control pedal and felt the mild surge of acceleration as the low-powered rockets set me moving away from the station. After ten seconds of steady thrust, I cut off the drive. It would take me five minutes to coast the rest of the way, and not much longer to return with my salvage.

From WHO'S THERE? aka THE HAUNTED SPACE SUIT by Sir Arthur C. Clarke (1958)

All his life Gibson had been fascinated by gadgets, and the spacesuit was yet another to add to the collection of mechanisms he had investigated and mastered. Bradley had been detailed to make sure that he understood the drill correctly, to take him out into space, and to see that he didn’t get lost.

Gibson had forgotten that the suits on the Ares had no legs, and that one simply sat inside them. That was sensible enough, since they were built for use under zero gravity, and not for walking on airless planets. The absence of flexible leg-joints greatly simplified the designs of the suits, which were nothing more than perspex-topped cylinders sprouting articulated arms at their upper ends.

Along the sides were mysterious flutings and bulges concerned with the air conditioning, radio, heat regulators, and the low-powered propulsion system. There was considerable freedom of movement inside them: one could withdraw one’s arms to get at the internal controls, and even take a meal without too many acrobatics.

Bradley had spent almost an hour in the airlock, making certain that Gibson understood all the main controls and catechising him on their operation. Gibson appreciated his thoroughness, but began to get a little impatient when the lesson showed no sign of ending. He eventually mutinied when Bradley started to explain the suit’s primitive sanitary arrangements. “Hang it all!” he protested, “we aren’t going to be outside that long!”

Bradley grinned. “You’d be surprised,” he said darkly, “just how many people make that mistake.”

He opened a compartment in the airlock wall and took out two spools of line, for all the world like fishermen’s reels. They locked firmly into mountings on the suits so that they could not be accidentally dislodged.

“Number One safety precaution,” he said. “Always have a lifeline anchoring you to the ship. Rules are made to be broken — but not this one. To make doubly sure, I’ll tie your suit to mine with another ten metres of cord. Now we’re ready to ascend the Matterhorn.”

The outer door slid aside. Gibson felt the last trace of air tugging at him as it escaped. The feeble impulse set him moving towards the exit, and he drifted slowly out into the stars.

The friction of the reel had checked his momentum when the cord attaching him to Bradley gave a jerk. He had almost forgotten his companion, who was now blasting away from the ship with the little gas jets at the base of his suit, towing Gibson behind him.

Gibson was quite startled when the other’s voice, echoing metallically from the speaker in his suit, shattered the silence.

“Don’t use your jets unless I tell you. We don’t want to build up too much speed, and we must be careful not to get our lines tangled.”

“All right,” said Gibson, vaguely annoyed at the intrusion into his privacy. He looked back at the ship. It was already several hundred metres away, and shrinking rapidly.

“How much line have we got?” he asked anxiously. There was no reply, and he had a moment of mild panic before remembering to press the “TRANSMIT” switch.

“About a kilometre,” Bradley answered when he repeated the question. “That’s enough to make one feel nice and lonely.”

“Suppose it broke?” asked Gibson, only half joking.

“It won’t. It could support your full weight, back on Earth. Even if it did, we could get back perfectly easily with our jets.”

“And if they ran out?”

“This is a very cheerful conversation. I can’t imagine that happening except through gross carelessness or about three simultaneous mechanical failures. Remember, there’s a spare propulsion unit for just such emergencies — and you’ve got warning indicators in the suit which let you know well before the main tank’s empty.”

“But just supposing,” insisted Gibson.

“In that case the only thing to do would be to switch on the suit’s S.O.S. beacon and wait until someone came out to haul you back. I doubt if they’d hurry, in such circumstances. Anyone who got himself in a mess like that wouldn’t receive much sympathy.”

From THE SANDS OF MARS by Sir Arthur C. Clarke (1951)

Space Taxi

A space taxi is a short ranged orbit to orbit vehicle used to carry astronauts and small amounts of cargo. At its simplest, it is a frame that astronauts attach themselves to, with a rocket engine at one end. More complicated taxis have an enclosed hull which may or may not be pressurized.

Do keep in mind that the direction of "down" will appear to be in the same direction the rocket exhaust shoots. The various illustrations are very misleading, making it look like the people are riding a taxi like it was a witch's broomstick. In reality it is more like riding a stripper's pole.


Orion Space Taxi
Specific Impulse450 s
Exhaust Velocity4,500 m/s
Wet Mass1,584 kg
Dry Mass759 kg
Mass Ratio2.0
ΔV3,120 m/s
Payload136 kg (2 people)
Length3 m
Diameter1 m wide
General Dynamics 2-Man Space Taxi
Specific Impulse450 s
Exhaust Velocity4,500 m/s
Wet Mass361 kg
Dry Mass155 kg
Propellant Mass206 kg
Mass Ratio2.3
ΔV3,750 m/s
Height3.5 m

In this document about Orion drive spacecraft, they mention a space taxi. It carries two crew members, has a hardware mass of 623 kilograms, and a propellant mass of 825 kilograms. As near as I can measure from the diagram, it can be approximated as a cylinder with a height of two meters and a radius of 0.5 meters, with a hemisphere of radius 0.5 meters on each end.

This gives it an internal volume of 2 m3. Assuming it has chemical propulsion, the propellant would take up about 0.8 cubic meters, and the two crew would take up 0.14 cubic meters. Carrying two crew, it would have a mass ratio of about 2, and thus a deltaV of about 3,120 m/s.

In Volume 10: "Space Age in Fiscal Year 2001". Proceedings of the Fourth AAS Goddard Memorial Symposium, 15-16 March 1966, Washinton DC Krafft Ehricke has a diagram featuring what appears to be the same space taxi.

General Dynamics had designs for one and two-man space taxis that again appear to be the same ones. The two man version was described to have a dry mass of 155 kg and 206 kg of propellant (probably space storage hpergolic propellants). This would give it a mass ratio of 2.3 and thus a deltaVof about 3,750 m/s. For more details refer to US Spacecraft Projects #01 by Scott Lowther.


A helpful reader named Yoel Mizrahi (יואל מזרחי) contacted me and told me about the Marquardt Space Sled, and supplied some images.

Not much is known about this artifact. It was made by the Marquardt Corporation in the 1960 as part of a project to develop an EVA maneuvering unit. It was tested in 1965. It was shelved in favor of a project that eventually developed NASA's Manned Maneuvering Unit. It is currently on display at the National Museum of the United States Air Force in Dayton, Ohio.

The unit had a length of about 2.1 meters and a mass of about 91 kilograms.

Expert Scott Lowther was puzzled by the unit. He guesses it was part of the MOL project. He notes that it is unclear if the device was actually intended to be used in space, or in an earth-bound test mounted on air bearings or something. The seat, for example, is not constructed out of materials which could withstand the harsh solar radiation or vacuum of space. The chair also cannot accommodate a space suit's back pack.

And exactly where are the rocket thrusters?

Presumably the huge sphere up front is a high-pressure gas tank, and the thrusters were cold-gas jets. In which case it is not clear what, if any, advantages this holds over a backpack style MMU.

But Mr. Lowther is of the opinion that if it was uprated to use monopropellant (or even bipropellant) then you'd have an honest-to-Johnny space motorcycle.

Michel Van figures the unit was intended to be used in the USAF "Vomit Comet" as a proof of concept, which would explain the seat anomalies.


(ed note: the crew of the Manned Orbital Station watch in horror as the world is consumed by global thermonuclear war)

      The long-scan radar operator said, “I have a bogie. ETA forty minutes”.
     “Sugiyama, what is it?” demanded Farrington.
     Sugiyarna moved to the radar console. The NCO in charge traced the blip for him. Sugiyama turned, his eyes wide.
     “It’s a warhead, Colonel. Unpowered. Maybe a MIRV warhead off course.”
     “How close?” Farrington demanded.
     “Collision course,” Sugiyama said. “Thirty-eight minutes.”
     “It’s pretty definitely a MIRV warhead,” Longo said, examining the orbitals.
     “Some damned Commie deliberately took a pot shot at us,” Rothgate exclaimed fiercely. “Damn them, we’re not a military target.”
     “No matter. If that thing comes within a thousand feet of us, we’ll trigger its radar fuse,” said Farrington.

     “Give me three men and four EVA bugs,” said Longo. “Maybe we can intercept it.”
     “And detonate the thing?” Rothgate asked. “That’s a small help.”
     “No,” Longo replied. “If we get to it soon enough, We can apply thrust with the bugs and jockey it to a higher or lower orbit.”
     “I’ll go with you,” said Steinbrunner. “I’ve had plenty of experience on EVA. You’d better choose two other men who’ve logged at least twenty hours on extravehicular activity.”
     “Very well,” Farrington said. “Take Bruce and Piaseki. They’ve both been working outdoors for several weeks”
     Sugiyama keyed the intercom and sent out the call for the men to report at the hub. Longo led the way, Steinbrunner following. “We’ll keep tracking the bogie,” Farrington called after him. “I’ll let you know when you’ve goosed it enough.”
     “If we’ve goosed it enough,” Longo heard Steinbrunner mutter behind him, but ignored him.

     They transversed the rim of the wheel to the nearest lateral passage and entered. The Mylar-and-metal passage bore handholds along its passage, which became necessary as they approached the hub and lost the last of the impressed centrifugal pseudogravity. The two other men were waiting for them in the hub.
     “Bruce, go with Steinbrunner,” Longo ordered. “Piaseki, you’re with me. Do you know which bugs have been refueled recently?”
     “Numbers five, three, and one are fresh,” Bruce said. “Number two has been out for about half an hour. All of the others are low.”
     “All right, one, three, and five it is,” Longo said, activating the hatch. They donned white suits, entered the small air lock, and waited as the door closed and the airlock cycled. Interminable seconds later, the outer hatch slid aside. The dark blackness of space outside was cut by the brilliance of sunlight, reflecting from the wheel and from the distant moonship. They moved out, holding to the stanchions cemented to the hub. There were six EVA bugs moored near the spoke that entered the hub at this point. Their numbers were stenciled in large red letters on their sides. Longo made a slow motion with his arm. Steinbrunner and Bruce cast off, using their back packs to propel themselves to the bugs marked l and 2.
     Longo touched the stud on his chest and felt the soft pressure of a peroxide jet push him toward number 5. He turned once to watch the heavy figure of Piaseki following him with a dreamlike slowness. He drifted himself into the pilot’s seat of the EVA bug, and waited as Piaseki settled into the seat of number 3 near him.

     He touched the communication button on his chest and was rewarded with the sound of breathing. “All right,” he said. “We’ll have to cancel some of our orbital velocity. That will cause us to decay until the bogie catches up with us. Then we’ll have to goose these buggies fast to match velocity with the thing. Under no circumstances is anyone to get in front of the bird. We don’t know how sensitive the radar fuses are, although they should be relatively insensitive to anything as small as us.
     “Right,” Steinbrunner replied laconically.
     “Let’s go; keep it tight,” Longo said. He grasped the tiller of the bug and eased open the peroxide throttle. Deep in the vitals of the bug, 90 percent hydrogen peroxide vented into a chamber, hitting a bed of catalyst that instantly decomposed the peroxide to oxygen, water, and large quantities of heat. The water appeared as superheated steam and the resulting hot mixture vented through an expansion nozzle, emerging as a faint, rapidly dissipating cloud. The end result was thrust. The motor could be throttled as few liquid motors can, but this time Longo summoned full thrust. The resulting acceleration was nearly a full g, 32 ft/sec/sec. His velocity built rapidly. Rather, he reminded himself, his velocity decayed rapidly, since the thrust served to cancel some of his orbital velocity while altering the orientation of his orbit. The MIRV warhead was in an orbit that intersected the station orbit at a 20-degree angle. From his viewpoint he was approaching the still unseen warhead rapidly; actually, he was slowing down and allowing the warhead to overtake him. Their relative closing rate built rapidly in less than half a minute to five hundred miles an hour. He did not dare go faster, since he would have to regain the velocity he had lost to match with the warhead. In the meantime, in losing the velocity, his orbit was decaying so that he was dropping inside the orbit of the warhead.

     He looked around and saw that the other three bugs were matching his maneuver. All but number 2 within twenty feet of him and 2 was trailing by perhaps another ten feet. He could make out Steinbrunner’s massive figure, but the reflections from his faceplate obscured his features. He keyed the transceiver in his suit again and said, “MOS (Manned Orbital Station), have you locked on us?”
     “We’re reading you,” came Sugiyama’s voice tensely. “Your closing rate is four hundred and eighty mph. Orbital displacement is now approximately three hundred fifty feet. Estimated planar intercept in ten minutes.”
     “That’s not soon enough,” Longo said. “We’ll increase closing to six hundred mph.”
     “Your maneuvering g loading will be too great,” Sugiyama protested.
     “We’ll have to chance it.”

     “You should be in sight of the bird,” Sugiyama said. “It’s now about one hundred eighty miles from the station.”
     “There it is!” Piaseki’s voice cut into the transmission.
     Longo looked up and ahead. He saw the glint of dull metal and a second later made out the massive warhead. He muttered a silent prayer and signaled for reverse thrust. The bugs simultaneously activated their side thrusters and slowly, as in some mechanical ballet, turned one hundred eighty degrees.
     “Okay,” Longo said. “Match as quickly as you can.”
     It was a half-blind maneuver, since he couldn’t keep glancing back to watch as the warhead inexorably overtook them. They were pushing heavy acceleration now, regaining their lost velocity as quickly as possible.
     “Speed of closing now fifty mph,” Sugiyama said. Then: “Forty … thirty-five…”
     Longo stole a quick look behind him. The bird was drifting toward them now, their relative velocities down to a mere thirty miles an hour. In the meantime, the increased velocity of the bugs had raised their orbits. Now they were in danger of being run down. Longo applied some lateral thrust and waited fearfully as the warhead drifted abreast of his bug. The others surrounded it, matching velocity with vernier thrusters.

     “All right,” Longo ordered. “We’ll have to give it a quick push.”
     “Why not guide it into a lower orbit?” asked Bruce.
     “Because the orbit will eventually decay and that damned thing will land on somebody’s real estate below. There’s enough of that going on now.”
     The four bugs were maneuvering now, closing on the rear of the warhead. As they had surmised, it was a powered reentry body, Longo saw as they approached the squat conical nozzle of the reentry solid motor. He thought, hope something doesn’t trigger the motor while we’re maneuvering. The intense flame from the rocket would char them in a second.
     They lined up around the coupling skirt of the warhead, positioning the heads of the bugs against the stanchions welded to the skirt. Longo saw that the warhead had the typical boilerplate look of a Soviet device, and he saw stenciled Cyrillic inscriptions on one side of the skirt. He wondered what they meant. From somewhere the idiot thought came that they could well mean “This end up.”

     The bugs were all positioned now, and at Longo’s command they opened their throttles. Longo called out thrust figures from his accelerometer as the others tried to build their thrust in unison. At first the bird yawed slightly from Piaseki’s side, but the man quickly corrected.
     “Give me close tracking, Sugiyama,” Longo called.
     “Your delta V is fifteen feet per second … twenty … thirty …” Sugiyama chanted.
     Barely twenty miles per hour, Longo thought, signaling for more thrust. His bug chronometer told him they had barely ten minutes left. They’d have to use full throttle. He signaled, then shouted a warning as the bird started to yaw again.
     “Delta V one-fifty feet per second,” Sugiyama said. “One-eighty,” he said a minute later. Longo wondered if it would be enough.” He looked at his peroxide gauge and saw that his fuel level was dropping dangerously.
     “Two hundred,” Sugiyama called.
     He looked ahead and saw the silhouetted wheel of the MOS with the spiderweb moonship near it. He was looking down at an angle now and he realized that they had been steadily increasing their orbital altitude with the acceleration.
     “Watch it!” Steinbrunner yelled.
     Number 2 fell away, its fuel tanks exhausted. With the unbalanced thrust, the warhead began to tumble, its massive nose rotating toward Longo. He hit his forward verniers and prayed. The other bugs were falling back as well. He heard a metallic rubbing noise. The leading edge of the warhead scraped alarmingly across the front of his bug. For an instant he held his breath, wondering if the impact or the radar shadow of the bug would be sufficient to detonate the warhead. Nothing happened.

     He signaled the other men and they rotated their bugs, using the last of their thrust to cancel their forward velocity. As his motors sputtered out, Longo looked back and saw the bright point of the warhead move up and past the station. It was a good twenty-mile miss, he saw with relief. The bugs were rapidly overtaking the station. They would pass above and in front of it.
     “You’d better send a tow truck,” he told Sugiyama.
     “I’ve dispatched two cargo handlers We’ve been fueling,” Farrington’s voice came through. “A good job.”
     “That’s as close to a near miss as I want,” Longo said.

     “I’m not sure it makes much difference,” Farrington’s voice said tiredly.
     “What do you mean?” asked Longo.
     “We’ve been monitoring the background from below,” Farrington said. “Our computer model says it’s already ten times the A.E.C. maximum and still rising.”
     “Still rising?”
     “The bastards are still shooting at each other,” Farrington said.
     “But that means?—”
     “I’m well aware of what it means,” Farrington said. “It may mean the end of everything.”
     The end of the world, Longo thought. The words had no meaning. He felt cold and distant, unable to apprehend the enormity of what the colonel had said.

     They were back aboard the station in a little over an hour. The cargo handlers carried peroxide charges for their bugs and they were able to return on their own power. Steinbrunner, who had fallen behind the group, was the last to be refueled and return to the hub.

From EARTHWRECK! by Thomas Scortia (1974)

      It's only fair to warn you, right at the start, that this is a story with no ending. But it has a definite beginning, for it was while we were both students at Astrotech that I met Julie. She was in her final year of solar physics when I was graduating, and during our last year at college we saw a good deal of each other. I've still got the woolen tam-o'-shanter she knitted so that I wouldn't bump my head against my space helmet. (No, I never had the nerve to wear it.)
     Unfortunately, when I was assigned to Satellite Two, Julie went to the Solar Observatory — at the same distance from Earth, but a couple of degrees eastward along the orbit. So there we were, sitting twenty-two thousand miles above the middle of Africa (geostationary orbit) — but with nine hundred miles of empty, hostile space between us.
     We'd resigned ourselves to waiting, with what patience we could muster, until our Earth leave was due in six months' time, when we had an unexpected stroke of luck. Less than half our tour of duty had passed when the head of the transport section suddenly announced that he was going outside with a butterfly net to catch meteors. He didn't become violent, but had to be shipped hastily back to Earth. I took over his job on a temporary basis and now had — in theory at least — the freedom of space.

     There were ten of the little low-powered rocket scooters under my proud command, as well as four of the larger interstation shuttles used to ferry stores and personnel from orbit to orbit. I couldn't hope to borrow one of those, but after several weeks of careful organizing I was able to carry out the plan I'd conceived some two micro-seconds after being told I was now head of transport.
     There's no need to tell how I juggled duty lists, cooked logs and fuel registers, and persuaded my colleagues to cover up for me. All that matters is that, about once a week, I would climb into my personal space suit, strap myself to the spidery framework of a Mark III Scooter, and drift away from the station at minimum power. When I was well clear, I'd go over to full throttle, and the tiny rocket motor would hustle me across the nine-hundred-mile gap to the observatory.
     The trip took about thirty minutes, and the navigational requirements were elementary (about 1.9 km/s ΔV brachistochrone). I could see where I was going and where I'd come from, yet I don't mind admitting that I often felt — well, a trifle lonely — around the mid-point of the journey. There was no other solid matter within almost five hundred miles — and it looked an awfully long way down to Earth. It was a great help, at such moments, to tune the suit radio to the general service band, and to listen to all the back-chat between ships and stations.
     At mid-flight I'd have to spin the scooter around and start braking, and ten minutes later the observatory would be close enough for its details to be visible to the unaided eye. Very shortly after that (five minutes) I'd drift up to a small, plastic pressure bubble that was in the process of being fitted out as a spectroscopic laboratory — and there would be Julie, waiting on the other side of the air lock…

     I won't pretend that we confined our discussions to the latest results in astrophysics, or the progress of the satellite construction schedule. Few things, indeed, were further from our thoughts; and the journey home always seemed to flash by at a quite astonishing speed.

     It was around mid-orbit on one of those homeward trips that the radar started to flash on my little control panel. There was something large at extreme range, and it was coming in fast. A meteor, I told myself — maybe even a small asteroid. Anything giving such a signal should be visible to the eye. I read off the bearings and searched the star fields in the indicated direction. The thought of a collision never even crossed my mind; space is so inconceivably vast that I was thousands of times safer than a man crossing a busy street on Earth.
     There it was — a bright and steadily growing star near the foot of Orion. It already outshone Rigel, and seconds later it was not merely a star, but had begun to show a visible disk. Now it was moving as fast as I could turn my head; it grew to a tiny, misshaped moon, then dwindled and shrank with that same silent, inexorable speed.
     I suppose I had a clear view of it for perhaps half a second, and that half-second has haunted me all my life. The — object — had already vanished by the time I thought of checking the radar again, so I had no way of gauging how close it came, and hence how large it really was. It could have been a small object a hundred feet away — or a very large one, ten miles off. There is no sense of perspective in space, and unless you know what you are looking at, you cannot judge its distance.
     Of course, it could have been a very large and oddly shaped meteor; I can never be sure that my eyes, straining to grasp the details of so swiftly moving an object, were not hopelessly deceived. I may have imagined that I saw that broken, crumpled prow, and the cluster of dark ports like the sightless sockets of a skull. Of one thing only was I certain, even in that brief and fragmentary vision. If it was a ship, it was not one of ours. Its shape was utterly alien, and it was very, very old.

From PASSER-BY by Arthur C. Clarke (1957)

      Matt pulled himself along, last in line, and found the scooter loaded. He could not find a place; the passenger racks were filled with space-suited cadets, busy strapping down.
     The cadet pilot beckoned to him. Matt picked his way forward and touched helmets. "Mister," said the oldster, "can you read instruments?"
     Guessing that he referred only to the simple instrument panel of a scooter, Matt answered, "Yes, sir."
     "Then get in the co-pilot's chair. What's your mass?"
     "Two eighty-seven, sir," Matt answered, giving the combined mass, in pounds, of himself and his suit with all its equipment. Matt strapped down, then looked around, trying to locate Tex and Oscar. He was feeling very important, even though a scooter requires a co-pilot about as much as a hog needs a spare tail.
     The oldster entered Mart's mass on his center-of-gravity and moment-of-inertia chart, stared at it thoughtfully and said to Matt, "Tell Gee-three to swap places with Bee-two."
     Matt switched on his walky-talky and gave the order. There was a scramble while a heavy-set youngster changed seats with a smaller cadet. The pilot gave a high sign to the cadet manning the hangar pocket; the scooter and its launching cradle swung out of the pocket, pushed by power-driven lazy tongs.
     A scooter is a passenger rocket reduced to its simplest terms and has been described as a hat rack with an outboard motor. It operates only in empty space and does not have to be streamlined.
     The rocket motor is unenclosed. Around it is a tier of light metal supports, the passenger rack. There is no "ship" in the sense of a hull, airtight compartments, etc. The passengers just belt themselves to the rack and let the rocket motor scoot them along.

From SPACE CADET by Robert Heinlein. 1948

The taxi looked like a huge, short salami, twenty feet long and eight in diameter. There was a small dome for the pilot to see out, and an air lock at the front, while the rear carried a small rocket motor. They went through the lock. Inside were two seats, fuel tanks, and steering assembly, as well as cargo space.

Jerry blasted off, after cranking a hand gyroscope to turn them. It was a weak, cautious blast that used little fuel. "Better to take your time and not waste fuel," he explained. "Once you get moving, there's nothing to stop you."

They drifted toward the rocket, turning over by the use of the gyroscope, and Jerry brought them to a stop with a single quick blast of the rocket tube. It was precise, beautiful work. They coasted a few feet away, while he turned them over again until the nose pointed to the rocket's lock, which was open.

"Slip your helmet back on, Jim," Jerry ordered. "Go out into the lock and catch that rope."

The man in the ship ahead had already thrown the cord. Jim found the end and fastened it to a bite inside the lock. The taxi was pulled up to the main lock, where it fitted snugly against the silicone-rubber gasket to make an airtight seal.

They took the passengers back, and then began making trips to ferry the supplies. These were dumped out of the big rocket by the pilot and his men. Apparently they put on space suits, evacuated the air from the cargo section and lock, and simply pitched the crates and pieces into space. It was Jim's job to go out of the taxi and secure these with cords to a ring on the back of the taxi, leaving enough distance so the rocket blast wouldn't hurt them.

From STEP TO THE STARS by Lester Del Rey (1954)

     Captain Stone sighed. "I'm going with you. Will your scooter take three?"
     "Sure, sure! It's got Reynolds saddles; set any balance you need."

     Hazel allotted one-fourth her fuel as safety margin, allotted the working balance for maximum accelerations, figuring the projected mass-ratios in her head.

     Hazel worked the new mass figures over; with Edith, her suit, and the spare bottle subtracted she had spare fuel.
     She lined up on City Hall by flywheel and stereo, spun on that axis to get the sun out of her eyes, clutched her gyros, and gave it the gun. The next thing she knew she was tumbling like a liner in free fall. She remembered from long habit to cut the throttle but only after a period of aimless acceleration, for she had been chucked around in her saddle, thrown against her belts, and could not at first find the throttle.

     Quickly she checked things over. There was not much that could go wrong with the little craft, it being only a rocket motor, an open rack with saddles and safety harness, and a minimum of instruments and controls. It was the gyros, of course; the motor had been sweet and hot. They were hunting the least bit, she found, that being the only evidence that they had just tumbled violently. Delicately she adjusted them by hand, putting her helmet against the case so that she could hear what she was doing.
     Only then did she try to find where they were and where they were going. Let's see—the Sun is over there—and that's Betelgeuse over yonder—so City Hall must be out that way. She ducked her helmet into the hemispherical "eye shade" of the stereo. Yup! there she be!
     The Eakers place was the obvious close-by point on which to measure her vector. She looked around for it, was startled to discover how far away it was. They must have coasted quite a distance while she was fiddling with the gyros. She measured the vector in amount and direction, then whistled. There were, she thought, few grocery shops out that way—darn few neighbors of any sort.
     But she kept trying to call Mrs. Eakers, or anyone else in range of her suit radio while she again lined up the ship for City, with offset to compensate for the new vector. She was cautious and most alert this time—in consequence she wasted only a few seconds of fuel when the gyros again tumbled.
     She unclutched the gyros and put them out of her mind, then took careful measure of the situation. The Eakers dump was now a planetary light in the sky, shrinking almost noticeably, but it was still the proper local reference point. She did not like the vector she got. As always, they seemed to be standing still in the exact center of a starry globe—but her instruments showed them speeding for empty space, headed clear outside the node.

     Carefully she lined up the craft by flywheel; carefully she checked it when it tried to swing past. She aimed both to offset the new and disastrous vector and to create a vector for City Hall. She intentionally left the gyros unclutched. Then she restrapped Lowell in his saddle, checked its position. "Hold still," she warned. "Move your little finger and Grandma will scalp you."
     Just as carefully she positioned herself, considering lever arms, masses, and angular moments in her head. Without gyros the craft must be balanced just so. "Now," she said to herself, "Hazel, we find out whether you are a pilot—or just a Sunday pilot." She ducked her helmet into the eyeshade, picked a distant blip on which to center her crosshairs, and gunned the craft.
     The blip wavered; she tried to rebalance by shifting her body. When the blip suddenly slipped off to one side she cut the throttle quickly. Again she checked her vector. Their situation was somewhat improved. Again she called for help, not stopping to cut the child out of hearing. He said nothing and looked grave.
     She went through the same routine, cutting power again when the craft "fell off its tail." She measured the vector, called for help—and did it all again. A dozen times she tried it. On the last try the thrust stopped with the throttle still wide open.
     With all fuel gone there was no need to be in a hurry. She measured her vector most carefully on the Eakers' ship, now far away, then checked the results against the City Hall blip, all the while calling for help. She ran through the figures again; in a fashion she had been successful. They were now unquestionably headed for City Hall, could not miss it by more than a few miles at most—almost jumping distance. But, while the vector was correct in direction, it was annoyingly small in quantity—six hundred and fifty miles at about forty miles an hour; they would be closest in about sixteen hours.

     Roger Stone explained. The twins looked at each other. "Dad," Castor said painfully, "you mean Hazel took Mother out in our scooter?"
     "Certainly." The twins questioned each other wordlessly again. "Why shouldn't she? Speak up."
     "Well, you see . . . well, it was like this—"
     "Speak up!"
     "There was a bearing wobble, or something, in one of the gyros," Pollux admitted miserably. "We were working on it."
     "You were? In Charlie's place!"
     "Well, we went over there to see what he had in the way of spare parts and, well, we got detained, sort of."
     Their father looked at them for several seconds with no expression of any sort. He then said in a flat voice, "You left a piece of ship's equipment out of commission. You failed to log it. You failed to report it to the Captain." He paused. "Go to your room."
     "But Dad! We want to help!"
     "Stay in your room; you are under arrest."

     Castor thought about it. "That's bad. That could be really bad." He added suddenly, "But quit jittering, just the same. Start thinking instead. What happened? We've got to reconstruct it."
     "'What happened?' Are you kidding? Look, the pesky thing tumbles, then anything can happen. No control."
     "Use your head, I said. What would Hazel do in this situation?"
     They both kept quiet for some moments, then Pollux said, "Cas, that derned thing always tumbled to the left, didn't it? Always."
     "What good does that do us? Left can be any direction."
     "No! You asked what Hazel would do. She'd be along her homing line, of course—and Hazel always oriented around her drive line so as to get the Sun on the back of her neck, if possible. Her eyes aren't too good."
     Castor screwed up his face, trying to visualize it. "Say Eakers' is off that way and City Hall over here; if the Sun is over on this side, then, when it tumbles, she'd vector off that way." He acted it with his hands.
     "Sure, sure! When you put in the right coordinates, that is. But what else would she do? What would you do? You'd vector back—I mean vector home."
     "Huh? How could she? With no gyros?"
     "Think about it. Would you quit? Hazel is a pilot. She'd ride that thing like a broomstick." He shaped the air with his hands. "So she'd be coming back, or trying to, along here—and everybody will be looking for her 'way over here."
     Castor scowled. "Could be."
     "It had better be. They'll be looking for her in a cone with its vertex at Eakers'—and they ought to be looking in a cone with its vertex right here, and along one side of it at that."

     When Charlie had dug his scooter out of the floating junkyard moored to his home they soon saw why he had refused to lend it. It seemed probable that no one else could possibly pilot it. Not only was it of vintage type, repaired with parts from many other sorts, but also the controls were arranged for a man with four hands. Charlie had been in free fall so long that he used his feet almost as readily for grasping and handling as does an ape; his space suit had had the feet thereof modified so that he could grasp things between the big toe and the second, as with Japanese stockings.

     The crate was old but Charlie had exceptionally large tanks on it; it could maintain a thrust for plenty of change-of-motion. Its jet felt as sweet as any. But it had no radar of any sort. "Charlie, how do you tell where you are in this thing?"
     "That" proved to be an antiquated radio compass loop. The twins had never seen one, knew how it worked only by theory. They were radar pilots, not used to conning by the seats of their suits. Seeing their faces Charlie added, "Shucks, if you've got any eye for angle, you don't need fancy gear. Anywhere within twenty miles of the City Hall, I don't even turn on my suit jet—I just jump."
     They cruised out the line that the twins had picked. Once in free fall Charlie taught them how to handle the compass loop. "Just plug it into your suit in place of your regular receiver. If you pick up a signal, swing the loop until it's least loud. That's the direction of the signal—an arrow right through the middle of the loop."
     "But which way? The loop faces both ways."
     "You have to know that. Or guess wrong and go back and try again."

     Charlie, anticipating what would be needed, had swung ship as soon as he had quit accelerating. Now he blasted back as much as he had accelerated, bringing them dead in space relative to City Hall and the node. He gave it a gentle extra bump to send them cruising slowly back the way they had come. Pollux listened, slowly swinging his loop. Castor strained his eyes, trying to see something, anything, other than the cold stars.
     "Got it again!" Pollux pounded his brother.
     Old Charlie killed their relative motion; waited. Pollux cautiously tried for a minimum, then swung the loop, and tried again. He pointed, indicating that it had to be one of two directions, a hundred and eighty degrees apart.
     "Which way?" Castor asked Charlie.
     "Over that way."
     "I can't see anything."
     "Me neither. I got a hunch."
     Castor did not argue. Either direction was equally likely. Charlie gunned it hard in the direction he had picked, roughly toward Vega. He had hardly cut the gun and let it coast in free fall when Pollux was nodding vigorously. They coasted for some minutes, with Pollux reporting the signal stronger and the minimum sharper . . . but still nothing in sight. Castor longed for radar. By now he could hear crying in his own phones. It could be Buster—it must be Buster.
     "There she is!"
     It was Charlie's shout. Castor could not see anything, even though old Charlie pointed it out to him. At last he got it—a point of light, buried in stars. Pollux unplugged from the compass when it was clear that what they saw was a mass, not a star, and in the proper direction. Old Charlie handled his craft as casually as a bicycle, bringing them up to it fast and killing his headway so that they were dead with it. He insisted on making the jump himself.

From THE ROLLING STONES by Robert Heinlein (1952)

(ed note: Cot-Vee = Cargo Orbital Transfer Vehicle {COTV}, Pot-Vee = Personnel Orbital Transfer Vehicle {POTV}, Eff-Mu = Extra Facility Maneuvering Unit {EFMU})

      There were few amenities on the Pot-Vee Edison. But since the transition to GEO Base took several hours, the craft did have a bathroom of sorts—nothing more than a simple adaptation of the proven technology of the SkyLab "waste management system," as the old NASA circumlocution labeled it. The Personnel Orbital Transfer Vehicle itself was just a double-decked cylindrical cabin section eighteen feet in diameter and fifty-five feet long with a control compartment, docking air lock, and tunnel forward. On its aft end was the cylindrical hydrogen-oxygen propulsion module, the common orbital propulsion module used for both Pot-Vees and Cot-Vees.

     "Easy flight today," Jackson remarked. "Three hours, fourteen minutes dock to dock. Relax and enjoy." (ed note: transit from LEO to GEO)
     "Pretty short time for such a high lift, isn't it?" Stan Meredith asked. "Planning on high boost?"
     "Naw! This flying sewer pipe is boost-limited to point-one-five gees because of its structure," Jackson explained. "Besides, we don't need the boost that's required for Earth-to-orbit. You'll hardly notice it now—but, man, it'll feel like a rock dropped on you after you've spent six weeks in weightlessness!"
     The Ancient Astronaut was right. There were some bangs, clanks, muffled clunks, and gentle jolts as the Edison undocked from LEO Base. And when the thrust of the oxygen-hydrogen rocket engines came on, there was the gentlest of accelerations, accompanied by a slight vibration and a damped shaking.
     "Combustion noise being transmitted through the thrust structure, plus a little bit of damped pogo oscillation," Fred Fitzsimmons explained.
     "Why didn't they get the pogo out of these ships before they put them into operation?" Dave Cabot asked. "Didn't pogo oscillations give the engineers all sorts of trouble on Saturn and the Space Shuttles?"
     Fred smiled. "Welcome to private-enterprise astronautics! There's worse vibrations in an airplane. It costs so much to get all pogo oscillations out of a design under all sorts of load conditions—and these Pot-Vees operate with all kinds of loads—that it's more cost-effective to let them shake . . . within reasonable limits, of course."
     "But won't this thing eventually shake apart?" A note of anxiety entered Dave's voice.
     "Nope," Fred replied. "Never had a Pot-Vee crumple yet. The engines are de-rated so much that the pogo doesn't affect them, and the engines themselves are modernized versions of very old, well-proven designs that never gave a bit of trouble."
     "RL-10s," Stan put in.
     There were no cabin windows in the Pot-Vee, so it was a three-hour flight without a view.

     Stan and Fred discovered that it took almost nineteen minutes just to get to Charlie Victor, Mod Four Seven. There were a lot of hatches to go through and a lot of modules to traverse. "Fred, if we don't find some faster way to move around this rabbit warren, a lot of people are going to be dead before we reach them," Stan pointed out, finally opening the hatch to Mod Four Seven.
     Fred was right behind him through the hatch. "I'll ask Doc to see Pratt about getting us an Eff-Mu."
     "What's that?"
     "Extra Facility Maneuvering Unit. A scooter to anybody but these acronym-happy engineers."

     "You want an Eff-Mu so you can get around GEO Base faster."
     "Right. We lost the hyperpyrexia case because we couldn't get there fast enough. It takes forever to go through all the hatches and corridors of GEO Base."
     "Stan, I agree on both counts," Tom replied. "You need an Eff-Mu, and all of us need to be able to get around GEO Base faster in emergencies. But do you think a standard two-man Eff-Mu will really do the job?"
     "Why not?"
     "Why don't Earth-bound paramedics use motorcycles?"
     "I see what you mean. We need room for the patient."
     "Roger. Eventually maybe not, but right now we've got to provide that, too. Is there any Eff-Mu type that'll handle the two of you plus a patient?"

Pratt called him. "Doc, your special ambulance is coming up in the next Cot-Vee supply ship. Should be docking in six hours at Portlock Foxtrot. We're also putting a docking collar module on the free end of your med module, so don't be disturbed when you hear noises. You'll be able to dock right to your sick bay."

(ed note: one hex module is a hexagonal prism, about 3.7 meters wall to wall (12 feet), 15.2 meters long (50 feet), and has a volume of 241 cubic meters (8,500 cubic feet)

     The Pumpkin turned out to be a masterpiece of quick-and-dirty engineering. It was half a hex module outfitted with a StarPacket vernier engine as its main propulsion system and a series of electric thrusters for maneuvering. It had no direct view to the outside universe, only an array of video displays—large windows in space were a constant trouble source because the state of the art couldn't keep them from leaking, and the Pumpkin's life-support consumables were limited to twenty-four man-hours with no recycling. The unit sported a universal docking collar on the end of the hex module opposite the StarPacket vernier engine.
     Tom went with Fred and Stan to take delivery of their new gadget and bring it around to the med module dock. Pratt's men had latched the half hex of a docking port and pressure lock to the med module a few hours earlier in an operation that took only twenty minutes. GEO Base had been designed like an Erector set with plug-in modules; there was no time to build pretty or permanent space facilities on this job.

     He looked over the panel. "Attitude indicator. Four relative velocity indicators linked to eight search radars and three lidars at will. Beacon transponders. You know, this really isn't that much different from flying airplanes on instruments."
     And it wasn't. They returned for their P-suits, loaded another twenty-four man-hours of oxygen aboard, then checked out the Pumpkin—propellant load, battery-charge level, life-support-system consumables level, and the rest of a three-page checklist that someone had managed to put together for the Pumpkin when it was assembled at LEO Base. The controls had been highly simplified and were like those of a helicopter, with two sidearm controllers and two foot pedals to provide control in roll, pitch, yaw, and translation in six degrees of freedom. The StarPacket vernier engine offered enough thrust to get the Pumpkin moving for fast sprints, while the electric thrusters—the same kind used to propel the SPS array modules from LEO Base—permitted the gentlest of velocity changes.

     The Pumpkin's saved a couple of people already. Three of us have learned how to operate it: Stan, Fred, and myself. Now I understand why space pilots are people who are instrument-rated airplane pilots and also own their own boats. "Flying" the Pumpkin is like flying an airplane by instruments; you must believe what those gauges are telling you, and you can't pay any attention to the inputs from your vestibular apparatus or from kinesthetic senses. Docking and undocking the Pumpkin is like bringing the S.S. Patrick Miller alongside and gently docking to a pier; the Pumpkin has far less momentum, however, and is probably more like docking a row boat. There isn't anything difficult about it provided you aren't in a hurry.
     That's going to be the biggest problem with the Pumpkin. When Fred and Stan are on a call, they're in a hurry. I expect to get reports of hard docks. I hope they don't crumple too much stuff until they learn how to handle the Pumpkin under the stress of an emergency. I'm not too worried about them crumpling the Pumpkin; all the stress is column loading on that hex module, and it'd take a big bump to make the structure fail in that mode.

     Together, they went through the power-up checklist. Total time, forty-two seconds. Less than three minutes after the call, Fred retracted the docking latches and backed the Pumpkin away from the med module on thruster power. While Fred was doing that, Tom interfaced the ship's computer with the one in GEO Base via radio link; he called up a three-dimensional display of the current GEO Base configuration and had the computer call out the location of the accident site.
     "Computer has fed course parameters to the guidance system," Tom reported. Fred slued the ship and coupled the autopilot.
     "Roger! Autopilot locked on. Stand by for thrust."
     Tom spoke over the radio. "Traffic, Pumpkin. Emergency. Departing med module under primary thrust for Array Subassembly Module One Zero Seven. Are we clear to boost?"
     Fred held his finger over the abort switch in anticipation of a possible Traffic delay. But it didn't come. "Pumpkin, Traffic. Clear to boost."
     The boost came with a little fishtailing. "Dammit!" Fred swore. "Doc, this autopilot doesn't warm up fast enough. We'll have to go manual follow-up."
     "I'll take it, Fred." Flying the Pumpkin wasn't as hard as flying a light airplane on instruments through an overcast at night. In this case, with the course already plotted by the computer, all Tom had to do was keep the marker bugs centered on the attitude-situation and relative-velocity displays. With the sidearm controller in one hand and the thruster and vernier throttles in the other, Tom didn't let the red Xs of the marker bugs deviate from the center of the display.
     They picked up the group of P-suited figures on video long before the computer called for retros. To keep the thruster and vernier discharges away from the P-suited workers, Tom slued the Pumpkin in yaw and applied retro thrust by vector.

     The paramedic didn't say anything, but reached over and activated Tom's P-suit backpack. Tom did the same for Fred. Only then did they disconnect from the Pumpkin's life-support system.
     "Dump pressure, Fred."
     Tom felt his suit pressurise as the atmosphere of the Pumpkin was dumped into space through spill valves that equalized the thrust produced. Normal procedure wouldn't have permitted dumping of pressure, nitrogen being the one gas that had to be brought up from Earth. In addition, the venting created a gas halo around the ship that might have permitted arcing of electrical equipment on the SPS array. But in an emergency where the Pumpkin had to be depressurized rapidly, there was no alternative.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

The long-distance shuttle, the Rather Not, had its permanent mooring in the hollow center of the Orb. A four-legged strutwork held it in place against the gentle centrifugal tug, so it remained fixed over a repair berth. Mara clipped onto a mooring line that ran out to the Rather Not and adroitly pushed off from the Orb’s inner wall. Tsubata watched her movement with a critical eye. After a moment of coasting she flexed and turned so that her feet pointed toward the shuttle. She squirted her jets and slowed perceptibly. As an extra fillip, she unclipped from the mooring lines a few meters away and landed catlike on the tail section.

“Good enough. Don‘t move till I get there,” Tsubata said over suit radio.

“Okay.” Mara watched him swim easily across the twenty meters between them. He probably wanted her to mess up the maneuver; it would be easy to document if he had a friend watching on 3-D and would make a good first entry in a file. She knew enough about organizations to guess that, if Tsubata wanted to get rid of her, he would have to build a thick folder of instances to prove incompetence.

As Tsubata moved toward her, Mara glanced around and attached her suit tie-line to the nearest pipe. Most shuttles she had seen were different, each thrown together from cannibalized spare parts that came to hand. The Rather Not had a few customized pieces and the magnetic shielding coils were considerably larger, but otherwise it was like the others—all bones and no skin. The pilot couch was located at dead center of gravity in the middle, surrounded by struts, tanks, pipes, hauling collars, and storage lockets, all placed to obscure as littie of the view as possible. A large ion engine was mounted behind the couch in gray housing. It was lumpy but balanced; it wouldn't go into spinover if a pilot made a wrong move.

As Tsubata touched down she glided away from him, perching on top of the pilot couch backrest.

“I told you not to move.” Tsubata came after her.

“You’re going to have to give me more latitude than that. I know you’re not exactly tingling with anticipation to see me out here, but that’s the way it’s got to be.”

Tsubata said nothing, waving a hand to dismiss the subject. “First, I’m going to make sure you know what every piece of equipment on this shuttle is for.”

Mara had expected to know most of it, but there was a bewildering maze of detail. There were systems for fuel feed, a pipe complex regulating attitude jets, three different super-conducting magnet configurations for screening against Van Allen belt particles, two overlapping electrical systems, navigation index, vector integrater, multiple communications rigs, an emergency high-gain antenna for work when the Orb and shuttle were not in line of sight, gyros, radio, hauling apparatus, repair parts, life support—all this had to be integrated so that a change in one system didn’t cause a malfunction in another. In the next three hours Mara gained considerable respect for Tsubata and his work. He made it clear to her that a shuttle could not be run by the book; like most human creations, it demanded intuition, craft, and a certain seat-of-the-pants shrewdness.

It wasn’t until two days later that Tsubata considered her competent enough to take the Rather Not out on a routine flight.

From IF THE STARS ARE GODS by Gregory Benford & Gordon Eklund (1977)

(ed note: Aeneas MacKenzie is being boosted into orbit by laser launcher.)

      Ten gravities for ninety seconds is easily within the tolerance of a healthy man; but Aeneas had no wish to prolong the experience. He was laid flat on his back in a nylon web, encased in baggy reflective coverall and under that a tight garment resembling a diver's wet suit (a skintight space suit). The neckseal and helmet were uncomfortable, and it was an effort to exhale against the higher pressures in the helmet.
     He had thought waiting for the launch the most unpleasant experience he'd ever had: lying awkwardly on his back, with no control of his destiny, enclosed in steel; then the laser cut in.
     He weighed far too much. His guts ached. Like the worst case of indigestion imaginable, he thought. There was no way to estimate the time. He tried counting, but it was too difficult, and he lost count somewhere. Surely he had been at eighty seconds? He started over again.
     There was noise, the loud, almost musical two-hundred-fifty-cycle tone of the explosions produced as the laser heated the air in the chamber under him—how close? he wondered. That great stabbing beam that could slice through metal aimed directly at him; he squirmed against the high gravity, and the effort was torture.
     The noises changed. The explosion tone drifted down the scale. He was beyond the atmosphere, and the laser was boiling off material from the thrust chamber, reaching closer and closer to him—

     Silence. The crushing weight was gone. He was falling endlessly, with no way to know. Was he in orbit? Or was he plunging downward to his doom? He closed his eyes to wait, and then he felt he was truly falling, with the sick sensations of a boat in motion—he opened his eyes again to orient himself in the capsule.
     Will they pick me up? There was no reason they shouldn't. New crewmen arrived weekly, and he was merely another. He listened for a voice, a signal, anything—
     "Hullo, laddie. All right in there?"
     Aeneas grabbed for the microphone and pressed the talk switch. "That was one hell of a ride." He fought for control of his voice. "I think I'm all right now."
     "Except that you feel like letting the world's record fart, right?" the voice said. "Go ahead. You'll feel better." (one of the drawbacks of a skintight space suit)
     He tried it. It helped.
     "Hang on there, mate. Be alongside in a minute," the voice said. It took less than that. There were clunks and thuds, and the capsule jarred with some impact. "Righto. You're new in this game, they tell me."
     "Yes, very," Aeneas replied.
     "Right. So we'll start by testing your suit. I've got a bottle attached to the outlet, crack the atmosphere evac valve a half turn, there's a good chap."
     A short moment of panic. The capsule held half an atmosphere. When the capsule was evacuated, only his helmet above the neckseal would contain pressure. The tight garment he wore was supposed to reinforce his own skin so that it would be able to hold the pressure differences, and it had worked in the ground training chamber; but there had been physicians waiting there. Aeneas did as he was told. As the air hissed out, the pressure in his guts returned, but worse.
     "Fart again, lad. How's the breathing?"
     "All right." He carried out the instruction. Again it helped. It was hard work to breathe out, but there didn't seem to be any problems.
     "Good. Open the valve the rest of the way and let's get you out of there." Pumps whirred, and he felt more sensations of internal pressure. The wetsuit was very tight around every part of his body. His heart pounded loudly, and he felt dizzy.
     "Now unstrap and open the hatch."

     The steel trap around him seemed comfortable and safe compared to what he might find outside. Aeneas gingerly unfastened the straps that held him to the D-frame-webbed bunk and immediately floated free. It took longer than he had thought it would to orient himself and get his feet braced so that he could turn the latches on the hatchway, but Aeneas was surprised to find that he had no trouble thinking of what had been the capsule "wall" as now "down" and the hatchway as "up." The falling sensation vanished as soon as there was something to do.
     The man outside hadn't mentioned the tether line on its reel on his belt, but the ground briefing had stressed that before the hatch was open he should clip the tether to the ring by the hatchway. That took fumbling, but he managed it.
     The hatch opened smoothly and he put his head outside. There was brilliant sunshine everywhere, and he was thankful for the sun visor and tinted faceplate of his helmet. Crisp shadows, Earth an enormous bulging circular mass of white clouds and blue sea, not below but just there; stars brilliant when he looked away from Earth and sun . . . he had seen the pictures a thousand times. It wasn't the same at all.

     He used his hands to rotate himself. There was an odd vehicle about seven meters long at the aft end of the capsule. Its nose was shoved into the capsule thrust chamber, and it reminded Aeneas of dogs (maybe "dog-sled?"). An open framework of thin aluminum bars with—saddles? But why not? A mirrored helmet atop bulky metallic shining coveralls perched on the nearest saddle. Aeneas couldn't see a face inside it.
     "One of the ones who listen, eh?" the voice said. "Jolly good. Now you see that line above you?" Aeneas looked up and saw an ordinary nylon rope. It seemed to be a solid rod. "Get hold of it and clip it on your belt. After that, reach inside and unclip your own line. And don't be slow about it." There was a pleasant note to the voice, but it expected to be obeyed.
     Aeneas complied quickly. He was reeled very slowly toward the spindly personnel carrier, and with a lot of difficulty and help from the pilot managed to get astride one of the saddles. His feet slipped easily under loops in the thing's "floor"—Aeneas supplied the quotation marks because there was only a minuscule grillwork there—and a safety harness went around his waist.

     Now that he was in the carrier, he could look around, and he did unashamedly.
     The launch crew had cut it pretty fine, Aeneas told himself. Heimdall floated less than a kilometer away.
     It looked like a junkyard. Two large curved cylindrical sausages on the ends of cables rotated around each other at a distance of nearly half a kilometer. The sausages had projections at crazy angles: solar cell arrays, shields, heat dissipation projectors connected to the station by piping, antennae. There was an inflated tube running from each cylinder to an amorphous blob between them, and part of the center structure rotated with the cylinders. Most of the center did not rotate.
     Other junk—the pregnant machinegun shapes of supply capsules, cylinders of all sizes, inflated structures of no recognizable shape—floated without apparent attachment near the axis of spin. Solar panels and orange sunshades lay everywhere. Heimdall had no real form.
     "Quite a sight, isn't it?" his companion said. "Name's Kit Penrose, old chap. Officer in charge of everything else. Weight control, atmosphere recycling, support systems, all the marvy things like that. Also the taxi driver. Who're you?"
     "Oh, Christ, a bloody Scot. You don't sound one. Engineer?"
     Aeneas shrugged, realized the gesture couldn't be seen, and said, "Like you. Little of everything, I suppose. And I'm American."
     "American, eh? Whoever or whatever you are, the ground crew seemed worried about you. Well, you're OK. Here we go." He did something to the panel in front of him and the spindly structure moved slowly toward the satellite. His capsule was still attached at the nose. "We'll just take this along, eh?" Penrose said.
     "Yes, my kit's in there." And I may need everything in it, Aeneas thought.
     It took a long time to cover the short distance to the station. Kittridge Penrose burned as little mass as possible. "Energy's cheap up here," he told Aeneas. He waved carelessly at the solar panels deployed everywhere and at mirrors fifty meters across that floated near the station. The mirrors were aluminized Mylar or something like it, very thin, supported by thin fiberglass wands to give them shape. "Plenty of energy. Not enough mass, though."

     As they neared Heimdall, it looked even more like a floating junkyard. There was a large cage of wire netting floating a hundred meters from the hub, and it held everything: discarded cargo and personnel capsules, air tanks, crates, and cylinders of every kind. It had no door except an inward pointing cone—an enormous fish trap, Aeneas thought. They headed for that, and when they reached it and killed their approach velocity, Penrose unfastened himself from the saddle and dove into Aeneas' capsule.
     He emerged with two sealed cylindrical fiberglass containers of gear Aeneas had brought up and clipped them to the wire net of the cage. He did the same with the spindle vehicle they'd crossed on, then did something that released the personnel capsule from its faintly obscene position on the taxi's nose. Penrose gripped the cage with one hand and strained to shove the discarded capsule with the other.
     Nothing seemed to happen. Then the capsule moved, very slowly, down the tube into the cage; the motion was only barely apparent, but Penrose turned away. "Takes care of that. We'll have a crew come take it apart later. Now for you. I'll carry your luggage."
     He reached down and pulled the safety line out of the reel on Aeneas' belt and clipped it to his own. "Now you're tethered to me, but if you drift off and I have to pull you in, I'll charge extra for the ride. Follow me, and the trick is, don't move fast. Keep it slow and easy."

     They pulled themselves across the wire cage. It looked like ordinary chicken wire to Aeneas, a more or less sphere of it a hundred meters in diameter. There were other blobs of wire cage floating around the station. When they got to the side of the cage facing Heimdall, Aeneas saw a thin line running from the cage to the nonrotating hub between the cylinders. Up close the rotating cylinders on their cables and inflated tunnel looked much larger than before; twenty meters in diameter, and made of segments, each segment at least twenty meters long. They pulled themselves gingerly along the tether line to an opening ahead.
     There was no air in the part of the hub they entered. Penrose explained that the interface between rotating and nonrotating parts was kept in vacuum. Once inside, Aeneas felt a gentle tug as the long tube, leading to the capsules at the end of the tether line pushed against him until he was rotating with it.
     Before Aeneas could ask, Penrose pointed up the tube away from the direction they were going. "Counterweights up there," he said. "We run them up and down to conserve angular momentum. Don't have to spend mass to adjust rotation every time somebody leaves or comes aboard. Course we have to use mass to stop ourselves rotating when we leave, but I've got an idea for a way to fix that too."

     As they descended, Aeneas felt more weight; it increased steadily. They passed into the first of a series of multiple airlocks. Then another, and another. "Hell of a lot easier than pumping all this up every time," Penrose said. "Feel pressure now?"
     "A little. It's easier to exhale."
     "You could breathe here. Not well." They passed through another set of airlocks and felt increasing weight; after that it was necessary to climb down a ladder. The walls of the silo they were descending were about three meters in diameter. They stood out stiffly from the pressure and seemed to be made of the same rubberized cloth as his pressure suit, but not porous or permeable as his suit was.
     Eventually they reached a final airlock, and below that the silo had metallic walls instead of the inflated nylon. The final airlock opened onto a circular staircase and they climbed down that into the cylindrical structure of the station itself.

From HIGH JUSTICE by Jerry Pournelle (1974)

(ed note: Cot-Vee = Cargo Orbital Transfer Vehicle {COTV}, Pot-Vee = Personnel Orbital Transfer Vehicle {POTV}, Eff-Mu = Extra Facility Maneuvering Unit {EFMU})

      “Med, emergency in progress. Please stand by for possible rescue attempt. Better stand by with Pumpkin Array Subassembly Module Two Zero Two’s on its way up from LEO Base. They’ve had an accident. The survivors are in the personnel module, with the life-support system out and only a UHF emergency locator transmitter with limited voice capability.”
     “How many casualties?” Torn asked.
     “The brief report said three dead—one on EVA, the other two in the control module when it dumped to vacuum. The remaining four are apparently alive and uninjured in the personnel module, but they have life-support air for only an estimated seven hours.”
     Tom turned to Fred Fitzsinnnons. “Stumpy, power-up the Pumpkin and be ready to go. I don’t know where the subassembly is or whether we can reach. it with the Pumpkin. I’m going to Central. Dorothy, get things ready here for hypoxia therapy and possible abaryia resuscitation.”

     Tom located Herb Pratt surrounded by a bank of readouts and panels at Central’s main overview consoles. “We’ve got Doc Noels here now,” Pratt addressed the other three images on the screens. “Doc, are your people standing by to handle whatever medical problems might arise from this?”
     “We’re always ready for whatever crisis arises,” Tom replied curtly. “Can you tell me what’s going on, please? You’ve got a problem? Where are the Edison and the Steinmetz? Can’t those Pot-Vees rendezvous?”
     “Doc, if you’ll listen, you’ll discover what our problems are,” Pratt told him with uncharacteristic tact, either because he had really come to respect the GEO Base doctor or because the Hawk was on the conference net.

     “Array Subassembly Module Two Zero Two left LEO Base on schedule,” Pratt forged ahead. “According to its trajectory, the electric thrusters would boost it to GEO Base in seventeen-point-two hours. The normal crew of seven was aboard—two guidance-and-control technicians, two electric-thruster mechanics, two power-bus controllers, and the array commander. At fourteen-twenty-one, Zulu time, one of the electric-thruster mechanics, Bob Henson, got into his P-suit, cycled through the transfer lock, and powered-up the Eff-Mu to go out and check Thrusters Five and Eleven on the far dorsal surface of the array. Both thrusters were acting intermittently. There was no telemetry on the Elf-Mu, so we don’t know what happened when Henson started to move out along the array. Maybe a thruster valve stuck—we’ll never know. But he put the Eff-Mu right through the side of the pressurized control module.
     “The pressure in the control module dumped immediately,” Pratt continued soberly, “killing Lem Udevitz, the subassembly commander, and Sally Renquist, a control tech: As a matter of fact, they were blown out through the hole in the module wall. The presence of that much gas in the vicinity of the array, plus the presence of the Eff-Mu, which may also have dumped to vacuum and added to the out-gassing, caused the main array bus-bar junctions near the control module to arc. You don’t short out a nineteen-megawatt array subassembly without fun and games. All the protective circuits activated. The bus bars acted like massive fuse links and vaporized. We don’t know what happened to Henson and the Eff-Mu, but our radar signature says the Eff-Mu isn’t anywhere around the subassembly now. It may have been vaporized in the arc-over, or it may be tumbling out of control with all circuits dead somewhere between here and LEO Base.”
     Pratt checked two computer display readouts. “They lost most of the pressure in the living module before somebody slapped something over the holes and sealed them. Three of the survivors suffered the bends from the rapid decompression. Fortunately, one of the power-bus controllers was in her P-suit and was able to act quickly enough to save most of the life-support consumable gases for the module.
     “At this point, four of them are still alive in P-suits in the living module with emergency battery power for illumination. They’ve got their P-suits plugged into the emergency life-support fittings, and they’re trying to scavenge as much of the life-support consumables as possible. The power-bus controller found the emergency locator transmitter (ELT), got it on the air, and transmitted the basic elements of this report. Then she shut down the voice-transmission capability to conserve battery power. We’re still picking up the locator signal.”
     Pratt looked around at the three screens and concluded, “Here’s the problem: They’ve got … uh … seven-point-eight hours of life-support consumables left, according to calculations based on information received in the brief ELT report. The Edison is one-point-three hours from docking at LEO Base; no way for Nat Wallace to turn it around and head for the accident scene. He’s running heavy. He’ll have to be refueled, and that will take at least two hours after he docks. There’s no way he can make it to Two Zero Two before they run out of air.
     “The Steinmetz is two-point-nine hours from docking at GEO Base, and Ross Jackson’s running loaded with enough delta-v plus standard reserves to make GEO Base rendezvous, period. There’s no way he can reshape orbit to get to Two Zero Two in time, and when he got there he couldn’t do anything because he has only enough life-support for his passenger manifest, plus normal reserves. He wouldn’t have the delta-v capability to get to either LEO Base or GEO Base afterward. We’d just have a Pot-Vee and fifty more people stranded along with the subassembly.”
     Pratt looked around again. “That’s it in a nutshell, confirmed as best we can by radar track and signature analysis from here. We’re rechecking as many permutations and combinations as possible with computer runs, looking for some trajectory that would let us rendezvous a Pot-Vee with Two Zero Two, but we haven’t found it yet.

     “One guidance-and-control tech, Pat Mulligan. One electric-thruster mechanic, Jim Service,” Charlie Day announced from LEO Base as he checked his departure manifests. “And two power-bus controllers, Ed Swenson and Lucky Hertzog—Lucky was the one in the P-suit when the accident happened, and she was the one who sent the report.”
     Lucky? In that accident? With less than eight hours of life-support left? And no way to get to them with the Pot-Vees? Tom swallowed and tried to think straight. Given the situation, what could be done? What could he do?
     Finally, Owen Hocksmith broke the brief silence. “Four people and damned little time. Anybody got any ideas? To hell with the schedule, and to hell with the rules! Somehow, we’ve got to make an effort to get to them. No, we’ve got to get to them and bring them out of this alive!”

     There was silence from everyone on the conference net.
     “Dammit!” Hocksmith exploded. “We move thousands of tons of cargo and hundreds of people around in orbit every day! Surely there’s some way we can get to four people in a transfer orbit within seven hours and with enough lifesupport to keep them alive, even if it’s for just long enough to get a Pot-Vee turned around and on its way.”
     Dan Hills spoke up earnestly. “Let’s think about that one. We don’t have to get them and get back. We just have to get to them within seven hours with enough oxygen to sustain them until we can get a Pot-Vee there. Charlie, Herb, what do you have up there that one man can boost and control, carry about fifty man-hours of Oh-two (10 hours of oxygen for 1 rescue pilot and 4 survivors), no guidance system, vectors being fed to the pilot verbally from analysis of the radar track?”
     “I haven’t got an Eff-Mu big enough,” Charlie Day replied. “How about it, Herb? You’ve got Eff-Mus that are bigger. Do any of them have the delta-v to reach Two Zero Two in time with a pilot and fifty man-hours of Oh-two?”
     “Hold on, let me get a readout on the delta-v required for a seven-hour rendezvous.”

     Tom moved to another keypad and display. He had an idea. He didn’t know if it would work or not. He couldn’t do the math, and he couldn’t program the computer. But he had access to a very large general-purpose computer net: GALEN. He didn’t know if GALEN could handle celestial mechanics, but he could certainly ask.
     It could, using its links through EuroMed to computers in Brussels and London, plus a link into a DOD computer net through Bethesda Naval Hospital. He asked GALEN and its peripheral systems to solve the problem for him. GALEN already had all the parameters on the Pumpkin. All Tom had to do was feed it numbers on the location and trajectory of Two Zero Two and the location and orbit of GEO Base.
     When he was through, he had the answer.

     Dan Hills and Herb Pratt didn’t. “Mr. Hocksmith, the mission’s beyond the delta-v capabilities of any of our Eff-Mu vehicles,” Dan Hills announced. “They were designed as short-range craft for getting around the SPS during construction. They don’t have very much delta-v as a result.”
     “You’re the most negative problem solvers I’ve ever seen!” Hocksmith snapped back. “Four people out there, and we can’t come up with a way to get to them in time? Do you know what this could mean, gentlemen? It could mean that we get shut down for killing too many people. The hue and cry of the press could trigger the politicians and bureaucrats to do something, anything, to stop what they consider to be slaughter. We’re already in that position, as you damned well know. We’re supposed to be the world’s brightest people when it comes to space transportation. We’ve built and operated the biggest space transportation system in history. And we can damned well figure out some way to make it work to save four people! Think!

     Tom tapped Pratt on the shoulder and motioned for him to move over so he could get in the pickup’s field. The action came as such a surprise to Pratt that he moved immediately without a word. “Smitty, I’ve got an answer,” he told his old friend. “The Pumpkin, the GEO Base ambulance you designed for us, Smitty, It’s got more delta-v than any Eff-Mu because we need to move around fast here, which means high-g and gobs of thrust—in comparison, that is. It’s normally rated for a thousand pounds of payload. I’ve just been working with the GALEN computer, and I asked it whether or not I could get there as a single pilot in a P-suit with a cargo of five fifty-cubic-foot Oh-two backpack bottles. That’s about a hundred fifty pounds, plus me in a P-suit at two hundred pounds. Just to be on the safe side, I figured five hundred pounds; I may need some medical gear because three of those people are in severe pain with the bends. I can get there with the Pumpkin and enough Oh-two to save them. But I can’t get back. You’ll have to come rescue me with the Edison or the Steinmetz. That’ll give you ten hours after I make rendezvous. I can do it! Can you get to me in seventeen hours?
     “I won’t let you go,” was the comment from Hocksmith.
     “I won’t let Stan or Fred go. I’m a doctor, and those people may need a doctor, not a paramedic,” Tom explained.
     “We can get to you,” Pratt put in, looking at the display screen linked to GEO Base computer. “It’ll be close, but we’ll get there. Better take a couple of spare bottles, Doc, just in case.”
     “Can’t. I’ll be rendezvousing with electric thrusters as it is. Barely enough propellant to get me started and almost stopped. When it’s that critical, I want about five-percent reserve. Just get there within ten hours after I do, Herb.”
     Charlie Day broke in. “We’ll start from this end with the Edison, too. We’ll come after you from LEO and GEO. This operation’s got to have some redundancy built in somewhere!
     “Okay, I’ll be depending on both of you after I get to Two Zero Two,” Tom said. “I’ll fly by vectors from GEO Base radars and lidars. Herb, have your gang track me and give me those vectors. You’ll have my position, my trajectory, and your computer power—in short, all the data you’ll need. All I need is communication with you. No other way to do it.”
     “You’re right,” Herb remarked.
     “Tom, forget it! You’re not going!” Hocksmith yelled.
     “Smitty, you forget it! And shut up! You’re sitting on your ass down there with gravity and an atmosphere around you. Don’t try to run this operation by long distance. Herb, Charlie, and Dan work for you as employees—they’ve got to follow your orders. But I’m one of your contractors, and the Pumpkin was bailed to me by Eden Corporation. So you can’t tell me what to do at all! Or do you want four people to die?”
     Hocksmith threw up his hands. “Goddammit, go get’em, T.K.! But please be careful!”
     “A martyr I’m not,” Tom replied flatly. “Let’s go, Herb. Time’s a-wasting!”

     Tom was a little under his mass estimate. He did take a few extra backpack bottles and the equivalent of a spare fan belt. “I want a hand-portable communicator or a booster amplifier on my backpack radio, Herb. I will have to go EVA to get aboard Two Zero Two, and I want to be able to talk to you if necessary. I also want the unit as an ELT if something happens.”
     ;“We’ll give you a little extra delta-v, Tom,” Pratt told him. “I’ll have three of our Eff-Mus couple to you during GEO Base departure boost and supplement your own thruster on the Pumpkin. They’ll undock after they’ve boosted you. Sort of a two-stage vehicle. Computer says that’ll give you a ten-percent reserve—slim, but a hundred-percent improvement on the five-percent reserve you thought you’d need.”
     “Still going to be close, but thanks for the additional help,” Tom said as Fred buddy-checked the P-suit connections.

     The undocking was very gentle. Tom was reluctant to use any delta-v he didn’t have to. As he backed away from the med module’s docking. port, he saw on his displays that three Eff-Mus had drawn alongside. Into his helmet speaker came the voice of one of the Eff-Mu drivers. “Pumpkin, Eff-Mu Fourteen. We’re ready to move in and couple. Don’t try to hold position; let us move on you.”
     “Roger, Eff-Mu. GEO Base, Pumpkin, radio check.”
     “Loud and clear, Pumpkin. How me?”
     “Five by. While the Eff-Mus are coupling up, let’s check the data links.”
     “Go ahead, Pumpkin.”
     Tom exercised his small on-board computer, testing its megabyte memory (hah. Nowadays people have thousands of times more RAM in their smartphones. Not radiation-rated, though) and squirting the test data on the up-link to GEO Base, where the GEO computer examined it, determined it was all there, and echoed it back to the Pumpkin accompanied by its own test data. Within three seconds, the two computers were happy with each other and in communication.
     “Pumpkin, GEO Base,” Pratt’s voice called. “The Eff-Mus will maneuver you into boost attitude. We’re working this mission with Earth-oriented references, equatorial category.”
     Tom informed his computer and control systems. “Okay, Geo Base. Pumpkin’s ready for attitude positioning.”
     The three Eff-Mus gently lined up the Pumpkin.
     “Close enough,” Herb told Tom. “Your down-link data matches. Computer’s grinding out the final trajectory elements. Stand by for real-time updates on the up-link.”
     When the Pumpkin boosted from GEO Base on its errand of mercy, the computer estimated that Two Zero Two had six-point-nine hours of life-support available. The estimated trajectory time was six-point-eight hours.
     “I don’t like those numbers, Herb. Too many chances for error, and I know this is only a quarter-percent data.
     “No, we’ve got very accurate info on Two Zero Two. Air Force is feeding us their SpaceTrak data, too, and it cross-checks.”
     “Okay, Eff-Mus have separated,” Tom reported, “and I’m getting a solid up-link data signal. I’m on manual control.”

     When Tom had taken flight training from Dick Callins at the Roswell airport years before, he never thought he would find that detestable simulated-instrument hood training useful in flying a spacecraft. But that was exactly what he was doing. Instrument flight training had taught him to ignore the inputs from his otoliths and his kinesthetic senses, to give up flying by the seat of his pants. Then, as now, he was forced to rely only on the data that was presented to him by instruments. And it required the same degree of control precision—only the data presentation was slightly different.
     He still had a gyro attitude indicator and a gyro vector indicator. Otherwise, the instruments were fully electronic.
     It was a simple task for computers. Radar and lidar from LEO Base, GEO Base, and the Earth’s surface tracked the Great Pumpkin’s beacon, providing the computers with direction, range, and Doppler relative velocity. The computers were also receiving tracking data from the ELT beacon in Two Zero Two; they knew where it was—and where it was going to be. The instructions for right-left, up-down, and fast-slow were transmitted to the Pumpkin on the data up-link, where the ship’s computer converted the data for display, telling Tom how and how much to change direction or thrust. The Pumpkin's simple autopilot couldn’t be used on this long flight because neither it nor the Pumpkin’s inertial guidance system had the accuracy required. They didn’t have to be accurate for operating around GEO Base and the SPS assembly; they just had to keep general track of where the Pumpkin was. Thus, Tom had to fly the Pumpkin by hand, keeping dots of light centered on displays and making sure that the indicators on graphic displays stayed right on the lines.
     It wasn’t difficult, because nothing happened very fast as long as Tom kept on top of things constantly.

     “Going right down the tunnel, Pumpkin,” Pratt told him.
     “Any further messages from Two Zero Two, Herb?”
     “Nothing but the beacon signal,” the base boss reported. “Its code hasn’t changed and indicates the situation’s the same.”
     “Any way to get word to them that we’re coming?”
     “They have no receiver, and they’re sealed in that living module, so there’s no way to send even a laser signal to them.”
     “That’s got to be grim,” Tom observed.

     The Pumpkin was coming up on final trajectory velocity. Tom concentrated on the displays, his hand on the main throttle with the Vernier throttles just below. He was also receiving a verbal countdown from Pratt. Five feet per second short of final velocity, he chopped the main engine and used the verniers to bring the Pumpkin to precisely the required velocity.
     “Looks good, Pumpkin. Right down the pike. Take five, because we won’t do a mid-course correction for two hours yet. I want to let the trajectory errors build until we’ve got a reliable track that we can correct with greater precision. No sense burning up vernier delta-v by correcting every little glitch in the radar track.

     Tom couldn’t help but think of Lucky Hertzog, trapped in that can, knowing how much oxygen was remaining but not knowing whether anybody was on the way, and not being able to find out. He agonized because he knew it must be hell. On the other hand, he didn’t think Lucky would come apart under the circumstances. She was made of stout stuff. He knew there would be no hysteria, only tight-jawed discipline right to the very end if necessary.

     “Pumpkin, GEO Base. Here’s your latest ETA at Two Zero Two.” Herb’s voice returned him to reality. “It’s tight, Tom. The estimate’s converged with the flight time. We show a rendezvous only five minutes before life-support exhaustion. I think it’s too close to call. Let’s hope Two Zero Two has instituted drastic conservation measures. If they have, you’ll make it.”
     “I refuse to trust any computer when it comes to that close a call on the chances of living or dying,” Tom snapped back. “I’ll make it, Herb, because we’re dealing with people, not with computers.”
     He hoped he was right.

     Tom saw it on the forward screen through a ghostly haze of electric-thruster plasma. The huge solar array gleamed in the sunlight and bright specular reflections overloaded the video pickup, causing streaks of overexcited display phosphor to paint wiggly lines on the tube face. He fired the vernier thrusters carefully to rendezvous as precisely as possible with the personnel module that appeared only as a tiny polygon on the near end.
     According to the digital readout, he didn’t have a foot-second of delta-v to spare.
     The computer also told him he was running out of time.
     He’d have to move in on the personnel module with one single continuous application of the thruster in order to save time. Then he’d have to do a fast EVA.
     He had prepared for that. During the hours of coast-in, he’d pumped the Pumpkin’s cabin atmosphere back into the ship’s life-support system and carefully blown-down the cabin to vacuum; in fact, he had used the blow-down to provide some fractional delta-v, which gave him a trifle more reserve. He’d even opened the hatch to vacuum. When he got to Two Zero Two, he was ready to move—fast.

     Suddenly his instruments began reporting relative velocity between the Pumpkin and Two Zero Two. The computer was presenting projections and forecasts of future velocities, positions, and closing rates. He knew he would have to be exceptionally precise and that he had only one chance. He realized that this was the, same degree of precision he had to exercise as a surgeon, and, as in surgery, he had only one opportunity to succeed.
     “Gently! Positive pitch! Too much, back it off! Bang yaw right a couple of times. Coming right on in.” Tom talked to himself as he often did during an operation or during instrument approaches in his Maule. “GEO Base, Pumpkin! Closing nicely. I’m videotaping the monitors, but I’ll give you a verbal — There’s a big hole in the side of the command module and a series of smaller holes in the personnel module. The ones in the personnel module look as if they’ve been sealed from the inside. There’re no lights showing. I’m receiving only the modulated r-f signal from the ELT. Okay, closing slowly … Ten feet and dead in space. I’m holding it there. I don’t want to bump the personnel module because I don’t know what internal damage it’s suffered, and it could collapse if I whanged it. How’s my timing?”
     “Tom, it’s too close to call,” Pratt admitted.
     “Okay, I’m uncoupling, going to backpack. My transmission may get garbled because I’m switching to the booster transmitter strapped to the backpack. Now I’m free. Moving to the hatch, hauling the backpack bottles with me. Out of the hatch. What a mess! Everything seems to be covered with a grayish deposit. Probably vapor deposition caused by the arc-over. The survivors are lucky. The reflectance of that coating is probably just enough to maintain a comfortable interior temperature in the personnel module.”

     Tom pushed off the five feet across the void to the damaged module, not even taking the time to latch a safety line. He hit with both feet and bounced back in spite of the fact that he had used his knees to absorb his momentum. He would have bounded right back to the Pumpkin’s hatch except for the two-hundred-pound bag of backpack oxygen bottles in his left hand. Its momentum forced him around as it kept going and thudded into the module. He planted his feet on the module again, looked for. handholds, found them, and pulled himself to the hatch.
     He banged on the closed hatch and could feel the vibrations through the soles of his P-suit boots. There was no response.
     “Dammit, I’m too late!”
     He tried to twist the latch, but couldn’t do it. He had to hold on to the bag of oxygen bottles with his left hand and, therefore, could work only with his right. His body twisted instead. So he banged again, hoping he might somehow dislodge the hatch-closure dogs or that someone might detect his banging and open from inside.
     “Open up! For God’s sake, open up!” He found himself screaming in his helmet that was pressed against the hatch. Maybe his voice would penetrate by direct contact.
     He almost fell into the module when the hatch suddenly swung open.
     And he found himself faceplate to faceplate with Lucky. She touched helmets, and he heard her say, “Well, you took long enough to get here, but did you have to make such a racket?” She reached out, put her arms around the neck of his P-suit, and hauled him into the module.
     And she continued to hold him tight.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

Jury-Rigged Space Taxi

Sometimes space taxies are put together out of odds and ends. This can be done by teenagers raiding a spacecraft boneyard (much like greasers in the 1950s would make an automobile out of parts scavenged from a junk yard) or by survivors of a spacecraft disaster who need to slap together some kind of escape craft.

Tom Anderson suggested a puntastic name for the space age teenagers: vacuum-greasers. I must admit I was not entirely unamused.

Sometimes the jury-rig is straightforward, where one takes modular components from three wrecked spaceships and snap them together into one un-wrecked ship. Sometimes it is more cut-and-try, where you start with a surviving engine module and weld a habitat module on top. Sometimes weapons can be repurposed, i.e., taking a missile and replacing the warhead with a pilot's chair. Or turning a gun turret with a railgun into an impromptu cabin with built-in mass-driver thruster (that actually would not take much work, assuming the power supply can be attached).

And sometimes it has to be real creative, where the engineer starts from first principles and brainstorms a clever way to use Newton's Third Law to create thrust. Such creativity is needed when the poor engineer does not have much to start with, i.e., all the engines are utterly ruined or there are no engines available. The solution commonly takes the form of tanks of pressurized gas or boilers used to convert water into steam.

A futuristic teenager making their own space taxi out of scrap heap parts would have similar advantages to a 1950s teen building a car. It is a heck of a lot cheaper than buying a new or used car (which is a crucial point for the economically disadvantaged). The teen will learn marketable mechanic/engineer skills. And they will also obtain the classic advantage of Maker Culture: "I made it so I can fix it." The main draw-back is that it can take several years to actually make a functional car/taxi.

Peripherally related are some children's science fantasy novels where kids build a spaceship in their garage, such as The Wonderful Flight to the Mushroom Planet, Rusty's Space Ship, and Explorers. These generally have the format of the kids making the body of the ship, while some extraterrestrial helpfully provides the propulsion and life support. A borderline case is the TV show Salvage 1.

Rocket Tumble

One of the most important things to get right when making a jury-rigged space taxi is to be sure the engine's thrust axis passes through the taxi's center of gravity. Otherwise the taxi will suffer from the dread horror of rocket tumble. The taxi will move in a savage spiral path. In extreme cases it won't move at all, merely spin in place at high velocity.

In the latter case, may I suggest that the disaster be referred to as a "Catherine wheel". Because the space taxi will resemble the Catherine wheel firework, while the pilot will resemble the Catherine wheel torture device.

Even if the taxi is balanced with no passengers or payload, you have to load it carefully. Fill out a center-of-gravity and moment-of-inertia chart unless you are St. Catherine.


candle (n.): A candle, or putt-putt, is the simplest transport spacecraft that can be devised, consisting essentially of a tank of hypergolic rocket fuel powering a thrust motor and a simple reaction-control frame. The pilot, supported by their vacuum suit, rides the candle — the tank itself — in much the same manner as a velocipede.

The additional accoutrements and controls of a candle vary widely by type. Most common are stabilization gyros, to make their handling less temperamental in the face of mass shifts. Commercial models often include a range of accessories: fly-by-wire navigation, Orbital Positioning Systems (space version of GPS), a comfortable saddle and space for passengers, cargo panniers, canned life support reserves, and so forth.

But the virtue of a candle is its simplicity. One can be put together out of parts readily obtainable from even a half-stocked chandler, or for that matter from those lying around any wreckyard, or even crash site. Such a scrap-candle may consist of little more than the tank and motors, with handhold bars and lash-downs for bagged cargo welded on where they might be useful. Some go so far as to strip the navigation system down to a row of firing switches for each motor, requiring the pilot to figure burn times and vectors by eye, or at least by pocket-contents.

Indeed, in many spacer cultures across the Worlds, building one’s first candle from parts, salvaged, scrounged, and where necessary even purchased, is considered a rite of passage for the young. More cynical observers consider the true rite of passage being making one’s first candle flight without having to be ignominiously hauled home by the Orbit Guard.

- A Star Traveller’s Dictionary


(Alistair Young commissioned William Black to do the artist conception of Isif's Candle:

If you ask any spacer what a candle is, they'll tell you it's the simplest spacecraft imaginable, just the thing you need for commuting between nearby habs or spacecraft, playing tourist in the belt, or popping Outside for a quick satellite-servicing run. If you want more than that, there's always the entry in the Star Traveller's Dictionary.

So what Isif Alclair has built from the wreckage of her starship isn't technically what people most spacers would think of as a candle. lt's got an oversized nuclear thermal drive, for one thing, and much too much reaction mass for anything that would usually be attempted on a candle, and other distortions of the standard rigging. But then, it's also got a lot further to go if she wants to see home again.

And anyway, if it works out, no-one's going to quibble with her over nomenclature.)

(ed note: the protagonist is the sole survivor of a spacecraft disaster. They are cobbling together a candle (space taxi) out of usable parts salvaged from the wreck, hoping to fly to a place they can be rescued.)

But it’s true. Sleep well.

Puppet ackles activated. Primary personality execution SUSPENDED.

Warning: Medical alerts require review.
Warning: Life support status requires review.
Warning: Capability plat requires review.

Well, this hurts exactly as much as I remember.

So, let’s review what we have to work with, eigensister-mine (her eigensister is an electronic duplicate of her personality living in the candle's computer). We have most of a candle assembled, main frame, remass tank, a truss up front with navigational controls. I look upon our work and declare it good, partly because I can’t find anything wrong with it, and partly because if there’s anything more subtle wrong with it at this point, there’s nothing I can do about it anyway.

Because I have seven hours of native life-support left in this suit, and that is not even enough time to do the absolutely necessary, unless I want to try working on a pure-LOX tether. Which I really don’t, especially doing engineering work. So it’s going to be chemical overdrive, a wing, and a prayer. Afraid I’m going to have strained a few more tissues by the time I give you back to you.

Rough schedule:

Four hours: rip off the stubs of the old thrust-frame, and assemble a proper truss from structural members I have lying around here to bolt the drives to. I may have enough time to check balance on it; if not, attaching it anyway and counting on the gyros. Make sure I leave enough room in the center to clamp the cutter’s vector control core if I find it; at least it’s modular. Make sure there’s spare cabling back here for it.

One and a half hours: pull an accumulator stack from the battery room up above and maneuver it down here, then mount it above the forward truss. Hook it up to all the power inputs of things. If running ahead of schedule, consider circuit breakers.

Half an hour: Clamp the substrate/FDR box and my scavenged wireless node onto the forward truss. Power them up, run self-test, and while you’re doing that, rig some sort of clamp up there for my scavenged LOX tank.

Then migrate myself onto them, because my primary isn’t going to be able to fly this thing, however much she hopes to.

Last hour: Final steps. Acceleration couch from the cutter – nice as it would be to have the big seat with the hand controls, there’s no time to do a clean disconnect. Yank one of the non-pilot ones, and mount it on the front of the forward truss. Put one of the spare PLSS packs in its mounting, and run the LOX line into that; we’ll have to use its electrical heater rather than running a long line, but we’ve got power to spare if we give it an aux feed off the accumulator.

Using a spare pack means breathing shallow while changing the pack out, but it’s easier than wiring behind my back.

That leaves… no time. So no test, check-out, or proving. Well, okay.

It also leaves no time to do the software hacks necessary to integrate all this stuff, so I’m going to have to fork another me (duplicate yourself as an electronic person inside the candle's computers) to do that while I do the physical work. And since the processors on the candle are going to be pushing it to support one me, it looks like part of us doesn’t get to be rescued. Damn.

(ed note: To read the story from the beginnng, go here, scroll to the very bottom, and read the posts from the bottom to the top in chronological order)


      “We’re going to try to get you a job with Pittman, but your living arrangements are really none of our business,” Natalya said. “Except you’ve got no credentials. We’re hoping you have some qualifications.”
     He took a big slug of coffee and stared at them over his mug for a few heartbeats. “I built my first ship—such as it was—when I was ten. We lived on a mining station over in the Monarch system. Not a lot for a kid to do but fiddle around with parts. I built a little station-hopper. Used it to shuttle myself and loose scrap to the recycle hub there. It wasn’t much. A repurposed thruster as main engine. A saddle on the fuel tank. Some CO2 jets for steerage.
     “How’d you navigate?” Zoya asked.
     “Mark 1 eyeball and the seat of my pants. Thruster was on a push button. Press it for fire. Let go and it stopped pushing.” His gaze unfocused as if he watched the memories in his head. “Learned a lot about thrust, mass, and acceleration.” He shrugged. “Stopping was always an adventure. Banged into a lot of hard things before I got the hang of it.”
     “Your parents let you do this?” Natalya asked. “Mess with rocket parts?”
     His smile faded a bit. “Yeah. Well. They worked long hours.” He buried his face in his coffee mug and didn’t look up for a long time. “By the time I was fifteen, I was working along with them so ...” He shrugged. “Kids grow up fast in the belts.”

From SUICIDE RUN by Nathan Lowell (2018)

(ed note: Jordan and Treemonisha work for rival corporations, but have fallen in love with each other. Perhaps because there is nobody closer than half a billion kilometers (10 light-seconds), which is the separation between their rival space stations. Both stations are located 13 billion kilometers from Sol (87 AU, about 37 AU past the orbit of Pluto) right in the optimum location to intercept the beamcast of the alien Ophiuchi Hotline.

Tragically, a small black hole passes by. It damages Treemonisha's station but it almost destroys Jordan's. He sits in space in his spacesuit, waiting for death, but Treemonisha tells him to hang on, she has an idea.)

      (Treemonisha says) Haven’t you noticed anything?”

     The time-lag! (ordinarily there is a 20 second time lag between what you say and the response. she must have made a jury-rigged spaceship)

     Panic was rising again in his voice as he hoarsely whispered — “Where are you?”
     And instantly:
     “A thousand kilometers off your starboard fo’c’sle, mate, and closing fast. Look out toward Gemini, and in about thirty seconds you’ll see my exhaust as I try to bring this thing in without killing both of us.”
     “This thing? What is it?”
     “Spaceship. Hold on.”

     He got himself turned in time to see the burn commence. He knew when it shut off exactly how long the burn had been; he had seen it enough times. It was three and five-eighths seconds, the exact burn time for the first stage of the message rockets he had launched every day for almost a year.

     “Ooh! Quite a few gees packed into these things,” she said.
     “But how… ?”
     “Hold on a few minutes longer.” He did as he was asked.
     “Damn. Well, it can’t be helped, but I’m going to go by you at about fifty kilometers per hour, and half a kilometer away. You’ll have to jump for it, but I can throw you a line. You still have that rocket to push against?”
     “Yes, and I have quite a bit of fuel in my backpack. I can get to you. That’s pretty good shooting over that distance.”
     “Thanks. I didn’t have time for anything fancy, but I …”
     “Now you hush. I’m going to have to see this to believe it. Don’t spoil it for me.”

     And slowly, closing on him at a stately fifty kilometers per, was … a thing … that she had off-handedly called a spaceship.
     It was all rough-welded metal and ungainly struts and excess mass, but it flew. The heart of it was a series of racks for holding the message rocket first stages in clusters of ten. But dozens of fourth and fifth stages stuck out at odd angles, all connected by wire to Treemonisha’s old familiar lounging chair. All the padding and upholstery had frozen and been carelessly picked off. And in the chair was Treemonisha.

     “Better be ready in about fifty seconds.”

(ed note: Message rockets are tiny multistage rockets that carry recorded data-dumps from the station to a relay close enough to be in radio contact with Terra. In theory the stations could be equipped with large communication dishes, but the corporate bean-counters figured message rockets were more cost-effective.)

From THE BLACK HOLE PASSES by John Varley (1975)

(ed note: In the future people use handwavium paragravity to terraform asteroids. They also use them as torchships. Some royal morons want to move an inhabited asteroid from one cluster to another, an action that will spark a localized war. Our heroes Captain Dhan Gopal Radhakrishnan and Engineer Knud Axel Syrup arrive in the Mercury Girl, and are captured by the royal morons. All radios have been confiscated, so no warning can be broadcast. But our heroes figure out how to make a makeshift rocket out of local materials in order to travel to another asteroid to spread the alarm. They are forced to use only locally available materials.)

      The first beer-powered spaceship in history rested beneath a derrick by the main cargo hatch.

     It was not as impressive as Herr Syrup could have wished. Using a small traveling lift for the heavy work, he had joined four ten-ton casks of Nashornbräu end to end with a light framework. The taps had been removed from the kegs and their bungholes plugged, simple electrically-controlled Venturi valves in the plumb center being substituted. Jutting an orthogonal axes from each barrel there were also L-shaped exhaust pipes, by which it was hoped to control rotation and sideways motion. Various wires and shafts, their points of entry sealed with gunk, plunged into the barrels, ending in electric beaters (to agitate the beer. Much like shaking up a bottle of beer before opening the lid). A set of relays was intended to release each container as it was exhausted. The power for all this— it did not amount to much—came from a system of heavy-duty EXW batteries at the front end.
     Ahead of those batteries was fastened a box, some two meters square and three meters long. Sheets of plastic were set in its black-painted sides by way of windows. The torso and helmet of a spacesuit jutted from the roof, removably fastened in a screw-threaded hatch cover which could be turned around. Beside it was a small stovepipe valve holding two self-closing elastic diaphragms through which tools could be pushed without undue air loss. The box had been put together out of cardboard beer cases, bolted to a light metal frame and carefully sized and gunked.
     "You see,’’ Herr Syrup had explained grandly, "in dis situation, vat do ve need to go to New Vinshester? Not an atomic motor, for sure, because dere is almost neglishible gravity to overcome. Not a nice streamlined shape, because ve have no air hereabouts. Not great structural strengt’, for dere is no strain odder dan a very easy acceleration; so beer cardboard is strong enough for two, free men to sit on a box of it under Eart’ gravity. Not a fancy t’ermostatic system for so short a hop, for de sun is far avay, our own bodies make heat and losing dat heat by radiation is a slow process. If it does get too hot inside, ve can let a little vater evaporate into space though de stovepipe valve to cool us; if ve get shilly, ve can tap a little heat though a coil off de batteries.
     "All ve need is air. Not even mush air, since I is sitting most of de time and you ban a Martian. A pair of oxygen cylinders should make more dan enough; ja, and ve vill need a chemical, carbon-dioxide absorber, and some desiccating stuffs so you do not get a vater vapor drunk. For comfort ve vill take along a few bottles beer and some pretzels to nibble on.
     "As for de minimal boat itself, I have tested de exhaust velocity of hot, agitated beer against vacuum, and it is enough to accelerate us to a few hundred kilometers per hour, maybe t'ree hundred, if ve use a high enough mass ratio. And ve vill need a few simple navigating instruments, an ephemeris, slide rule, and so on. As a precaution, I install my bicycle in de cabin, hooked to a simple homemade g’enerator, yust a little electric motor yuggled around to be run in reverse, vit’ a rectifier. Dat vay, if de batteries get too veak ve can resharshe dem. And also a small, primitive oscillator ve can make, short range, ja, but able to run a gamut of freqvencies vit’ out exhausting de batteries, so ve can send an SOS ven ve ban qvite close to New Vinshester. Dey hear it and send a spaceship out to pick us up, and dat is dat.”

     The execution of this theory had been somewhat more difficult, but Herr Syrup’s ears aboard the Mercury Girl had made him a highly skilled improviser and jackleg inventor. Now, tired, greasy, and content, he smoked a well-earned pipe as he stood admiring his creation. Partly, he waited for the electric coils which surrounded the boat and tapped the ship’s power lines, to heat the beer sufficiently; but that was very nearly complete, to the point of unsafeness. And partly he waited for the ship to reach that orbital point which would give his boat full tangential velocity toward the goal; that would be in a couple of hours.
     Er … are you sure we had better not test it first?” asked Sarmishkidu uneasily.
     "No, I t’ink not,” said Herr Syrup. "First, it vould take too long to fix up an extra barrel. Ve been up here a veek or more vit’out a vord to Grendel. If O’Toole gets suspicious and looks t’ rough a telescope and sees us scooting around, right avay he sends up a lifeboat full of soldiers; vich is a second reason for not making a test flight.”
     "But, well, that is, suppose something goes wrong?”
     "Den de spacesuit keeps me alive for several hours and you can stand vacuum about de same lengt’ of time. Emily vill be vatching us t’rough de ship’s telescope, so she can let McConnell out and he can come rescue us.”
     "And what if he can’t find us? Or if we have an accident out of telescopic range from here? Space is a large volume.”
     “I prefer you vould not mention dat possibility,” said Herr Syrup with a touch of hauteur.

From A BICYCLE BUILT FOR BREW by Poul Anderson (1958)

(ed note: Keven, Glenda, and Jacob have been stranded on a tiny asteroid orbiting Ceres by the Bad Guys. They are in a mostly stripped base, trying to figure out how to get down to Ceres using only what is available)

     Kevin prowled through the corridors of their prison. There has to be some way, he told himself. Ceres mocked him from below, less than three hundred kilometers down. It hung huge in the night sky.
     Three hundred kilometers down, and we're moving about half a kilometer a second relative to Ceres, Kevin thought. That's not very much velocity. Under a thousand miles an hour. It doesn't take much energy to get to that speed. How much gasoline does it take to accelerate a car on Earth up to a hundred miles an hour—a gallon or so? We only need ten times that, not even that much.
     There's plenty of hydrogen and oxygen. Marvelous rocket fuels if we only had a rocket. More than enough to get us down, except that the temperature of hydrogen burning in oxygen is a lot hotter than anything we have to contain in it—
     No. That's not right. The fuel cells do it. But they do it by slowing down the reaction, and they can't be turned into rocket engines.
     He remembered the early German Rocket Society experiments described by Willy Ley. The Berliners had blown up more rockets than they flew, and they were only using gasoline, not hydrogen. Liquid-fuel rockets need big hairy pumps, and Kevin didn't have any pumps.
     What did he have? Fuel cells, plenty of them, and so what? An electric-powered rocket was theoretically possible, but Kevin didn't have the faintest idea of how to build one, even if there was enough equipment around to do it with. He wasn't sure anyone had ever built one—certainly he couldn't.
     Back to first principles, he thought. The only way to change velocity in space is with a rocket. What is a rocket? A machine for throwing mass overboard. The faster the mass thrown away goes in one direction, the faster the rocket will go in the other, and the less you have to throw. All rockets are no more than a means of spewing out mass in a narrow direction. A rocket could consist of a man sitting in a bucket and throwing rocks backward.
     That might get a few feet per second velocity change, but so what? There simply wasn't enough power in human muscles—even if he did have a lot of rocks. Was there any other way to throw them? Not fast; and unless the thrown-away mass had a high velocity, the rocket wouldn't be any use. He went on through the tunnels, looking at each piece of equipment he found, trying to think of how it might be used.
     You can throw anything overboard to make a rocket. Hydrogen, for example. That's all Wayfarer's engines did, heat up hydrogen and let it go out through the rocket nozzle. We have hydrogen under pressure— Not enough. Nowhere near enough hydrogen and nowhere near enough pressure, not to get velocity changes of hundreds of miles an hour. Ditto for oxygen. Gas under compression just can't furnish enough energy. What would? Chemical energy; burning hydrogen in oxygen would do it, but it gave off too much; there was nothing to contain that reaction except the fuel cells and they did it by slowing the reaction way down and—
     And I'm back where I started, Kevin thought. Plenty of energy in the fuel cells if I could find a way to use it. Could I heat a gas with electricity? Certainly, only how—
     His eye fell on the hot-water tank in the crew quarters. An electric hot-water tank. There was a pressure gauge: forty pounds per square inch. Forty p.s.i.—He looked at the tank as if seeing it for the first time, then went running back to the others.
     "Glenda, Jacob, I've got it."

     "Sure it works." Kevin grinned. "Steam at forty p.s.i. will come out fast. About a kilometer a second."
     "I believe you," Glenda said. "But it sounds silly. Steam rockets?"
     Kevin shrugged. "It is silly. There are a lot more efficient systems. But this will work—"
     "In a low g field," Jacob said. "You will not have much thrust. Of course you won't need much."
     "I'm sure it works," Kevin said. "Now all we have to do is build it." He made himself sound confident; he knew how much room for error there was in his figures. "Look, it takes nine hundred and eighty calories to turn a gram of water into steam. We heat that steam up another thirty or forty degrees and let it out. The energy is moving molecules. We know the molecular weight of water, so we can figure the number of molecules in a gram and—"

     They disconnected the hot-water tank and drilled holes in it. Several turns of heating wire went through the holes, then they sealed them in epoxy. At one end of the tank they drilled a large hole and threaded a pipe into it, threaded a large valve onto the pipe, and welded a makeshift rocket nozzle beyond that.
     When it was done they tethered the tank and filled it with water, then connected a fuel cell to the heating leads. "Here goes," Kevin said. He threw the switch to start the heaters.
     Slowly the water inside heated, then began to boil. The pressure shown on the gauge began to rise. In half an hour they had forty-five pounds of pressure. "All right, let's try it," Kevin said.
     Glenda turned the valve to let out steam. A jet of steam and water shot out across the surface of the moonlet. Ice crystals formed in space and slowly settled to the rocket surface. The jet reached far away from them, well off the moonlet itself. The tank pulled against its tether lines, stretching the rope.
     "It works!" Kevin shouted. "Damn it, we're going to make it!" He shut off the electricity. "Let's get her finished."

     It didn't look like a spaceship. It didn't even resemble a scooter, crude as those were. It looked like a hot-water tank with fuel cells bolted onto it. For controls it had vanes set crosswise in the exhaust stream, spring-loaded to center, with two tillers, one for each vane; a valve to control steam flow; and switches to connect the fuel cells to the heaters. Nothing else.
     The tank itself was fuzzy: They'd sprayed it with Styrofoam, building it up in layers until they had nearly a foot of insulation. There were straps on opposite sides of the tank to hold two passengers on.
     The tank held nearly a hundred gallons of water. Kevin calculated that they had more than enough energy to boil it all in their two fuel cells, and they would only need sixty gallons to get to Ceres. The number was so small that he ran it four times, but it was correct.
     The strangest part was the stability system: a pair of wheels taken from a mining cart and set up in front of the water tank. Electric motors rotated the wheels in opposite directions.
     The total mass of Galahad with full water tank was just under 550 kilograms.
     It took only a gentle effort to push the steam rocket away from the moonlet, but the cartwheel-gyros resisted any effort to turn it. Finally they got it oriented properly in space. Then they climbed aboard.
     "Full head of steam," Kevin said. "Almost fifty pounds. Ready?"
     He twisted the steam valve. At first both steam and water were expelled from the tank, but as they began to accelerate, the water settled and the exhaust valve let out only steam. C-2 dropped away. They missed it. It was a prison, but a safe one; now they had only their makeshift steam rocket.
     Galahad showed a tendency to tumble, but with the gyros resisting, they were able to control it with the steering vanes. A plume of steam shot from the tank, rapidly crystallizing into ice fog that engulfed them.
     "Damn. That's going to make it hard to see," Kevin said. "Nothing we can do about it." He peered down toward Ceres. It didn't seem any closer. Jacob's farewell faded in their headsets.
     Norsedal's calculations had shown that twenty minutes' thrust should be enough to cancel all their orbital velocity. It would use up just about half their fuel. Once Galahad was stopped dead in orbit above Ceres, they would fall toward the asteroid, and they would have half their steam left to counteract that.
     The trouble was that Jacob couldn't calculate how high above Ceres they would be when the twenty minutes were finished. As they lost velocity, they would lose altitude, and their orbit would no longer be a smooth circle, but an ellipse intersecting Ceres—somewhere. At the end of twenty minutes Kevin cut the power off. He was pleased that they still had thirty pounds of steam pressure.

     "Yes, but that's what the numbers say."
     "All right."
     And a year ago I was working equations in school, Kevin thought. Numbers to crunch and write down for examinations. Now they're something to stake your life on.

From EXILES TO GLORY by Jerry Pournelle (1977)

      There aren't many free-lance space-ferry operators who can claim that they carried a log cabin half way from Mars to Ganymede, and then had the log cabin carry them the rest of the way. I can, though you can bet your last tarnished megabuck that I didn't do it willingly. It was quite a trip. I left Mars not only with a log cabin on board, but a genuine muzzle-loading antique cannon, a goodly supply of cannonballs therefrom, and various other miscellaneous antiques—as well as the Curator of Historical Collections from the Ganymede Museum. There was also a stowaway on board, much to his surprise and mine—he wasn't listed in the cargo vouchers.
     Let me make one thing clear: I wasn't keen on carrying any such cargo. But my free-lance ferry operator's charter is quite explicit that way, unfortunately. A ferry operator is required to hire his ship to any person of law- abiding character who will meet the (government-fixed) rates, and whose cargo to be transported neither exceeds the ship's weight allowance nor is considered contraband by any System law.

     “Nothing live this time, Sam, except your passenger. She's Miss Vanderweghe of the Ganymede Museum. Curator of Historical Collections. She wants someone to ferry her back to Ganymede with some historical relics she's picked up along the way."
     “The Washington Monument?" I asked. “The Great Pyramid of Khufu? We could tow it alongside the ship, lashed down with twine—"
     “Knock it off," Cooper said, unamused. “What she's got are souvenirs of the Venusian Insurrection. The log cabin that served as Macintyre's headquarters, the cannon used to drive back the Bluecoats, and a few smaller knickknacks along those lines."
     “Hold it," I said. “You can't fit a log cabin into my ship. And if it's going to be a tow job, I want the Delivery Guaranteed clause stricken out of the contract. And how much does the damn cannon weigh? I've got a weight ceiling, you know."
     “I know. Her entire cargo is less than eight tons, cannon and all. It's well within your tonnage restrictions. And as for the log cabin, it doesn't need to be towed. She's agreed to take it apart for shipping, and reassemble it when it gets to Ganymede."

(ed note: after blast-off the captain wakes up to find an insane fanatic stowaway who is pounding the living snot out of the control panel with a crowbar. He is angry that Miss Vanderweghe has the historical relics and is determined that everybody involved will die. The captain manages to throw him out the airlock)

     There isn't any hesitation in a spaceman's mind when he finds a stowaway. Fuel is a precious thing, and so is air and food; stowaways simply aren't allowed to live. I didn't feel any qualms about what I did next, but all the same I was glad that Erna Vanderweghe wasn't awake and watching me while I went about it.
     I slipped into my breathing-helmet and sealed off the cabin. Opening the airlock, I carried the unconscious Venusian out the hatch and gave him a good push, imparting enough momentum to send him out on an orbit of his own. The compensating reaction pushed me back into the airlock. I closed the hatch. The Venusian must have died instantly, without ever knowing what was happening to him.
     Then I had a look-see to determine just how much damage the stowaway had been able to do before I woke up and caught him.

     It was plenty.

     All our communication equipment was gone, but permanently. The radio was a gutted ruin. The computer was smashed. Two auxiliary fuel tanks had been jettisoned. We were hopelessly off course in asteroid country, and the odds on reaching Ganymede looked mighty slim. By the time I finished making course corrections, we'd be down to our reserve fuel supply. Ganymede was about 350 million miles ahead of us. I didn't see how we were going to travel more than a tenth that distance before air and food troubles set in, and we weren't carrying enough fuel now for a safe landing even if we lived to reach Ganymede.

     I said, “We're in real trouble. We're off course and we don't have enough fuel for making corrections—not without jettisoning everything on board, ourselves included."
     “I don't mind if the cargo goes. I mean, I'd hate to lose it, but if you have to dump it—"
     “Uh-uh. The ship itself is the bulk of our mass. The problem isn't the cargo. If there were only some way of jettisoning the ship—"

     My mouth sagged open. No, I thought. It wouldn't ever work. It's too fantastic to consider.
     “I have an idea," I said. “We will jettison the ship. And we'll get to Ganymede."

     Luckily our saboteur friend hadn't bothered to rip up my charts. I spent half an hour feverishly thumbing through the volume devoted to asteroid orbits, while Erna hovered over my shoulder, not daring to ask questions but probably wondering just what in blazes I was figuring out.
     Pretty soon I had a list of a dozen likely asteroids. I narrowed it down to five, then to three, then to one. I missed the convenience of my computer, but regulations require a pilot to be able to get along without one in a pinch, and I got along.
     I computed a course toward the asteroid known as (719)-Albert. Luck was riding with us. (719)-Albert was on the outward swing of his orbit. On the basis of some extremely rough computations I worked out an orbit for our crippled ship that would match Albert's in a couple of hours.
     Finally, I looked up at Erna and grinned. “This is known as making a virtue out of necessity," I said. “Want to know what's going on?"
     “You bet I do."
     I leaned back. “We're on our way to a chunk of rock known as (719)-Albert, which is chugging along not far from here on its way through the asteroid belt. (719) -Albert is a rock about three miles in diameter. Figure that it's half the size of Deimos—and Deimos is about as small as a place can get."
     “But why are we going there?" she said, puzzled.
     “(719)-Albert has an exceedingly eccentric orbit—and I mean eccentric in its astronomical sense: not a peculiar orbit, just one that's very highly elongated. At perihelion (719)-Albert passes around 20 million miles from the orbit of Earth. At aphelion, which is where he's heading now, he comes within 90 million miles of the orbit of Jupiter. Unless my figures are completely cockeyed, Jupiter is going to be about 150 million miles from Albert about a week from now."

     I saw I had lost her completely. She said “But you said a little while ago that we hardly had enough fuel to take us 50 million miles."
     “In the ship," I said. “Yes. But I've got other ideas. We'll land on Albert and abandon the ship. Then we ride pickaback on the asteroid until its closest approach to Jupiter—and blast off without the ship."
     "Blast off—how?"
     I smiled triumphantly. “We'll make a raft out of your blessed logs," I said. “Attach one of the ship's rocket engines at the rear, and shove off. Escape velocity from Albert is so low it hardly matters. And since the mass of our raft will only be six or seven hundred pounds—Earthside weight, of course—instead of the thirty tons or so that this ship weighs, we'll be able to coast to Ganymede with plenty of fuel left to burn."

     I felt pretty clever about everything myself, three hours later, when we landed on the surface of an asteroid that could only be (719)-Albert. It had taken only one minor course correction to get us here. Which meant that my rule-of-thumb astrogation had been pretty good.
     We donned breathing-suits and clambered out of the ship to inspect our landfall. (719)-Albert wasn't very impressive. The landscape was mostly jagged upthrusts of a dark basalt-like rock. But the view was tremendous- a great backdrop of darkness, speckled with stars, and, much closer, the orbiting fragments of other lumps of rock. Albert's horizon was on the foreshortened side, dipping away almost before it began. Gravitational attraction was so meager it hardly counted. A healthy jump was likely to continue indefinitely upward, as I made clear to Erna right at the start. I didn't want her indulging in the usual hijinks that greenhorns are fond of when on a low-gravity planetoid such as this. I could visualize only too well the scene as she vanished into the void as the result of an overenthusiastic leap.
     We surveyed our holdings and found that there was enough food for two people for sixteen days—so we would make it with some to spare. The air supply was less abundant, but there was enough so we didn't need to begin worrying just yet.

     We set about building the raft.
     Erna dragged the logs out of the cargo hold—their weight didn't amount to anything, here, though I had to caution her about throwing them around carelessly; mass and weight aren't synonymous, and those logs were sturdy enough to knock me for a loop regardless of how little they seemed to weigh. She fetched, and I assembled. We used the thirteen longest logs for the body of the raft, and trussed a couple across the bottom, and a couple more at the top. To make blastoff a little easier, we built the raft propped up against a rock outcropping, at a 45° (actually they should have built the candle like a skyscraper, rocket engine at the bottom and raft balanced on the top, pointed 90° at the sky) angle.
     I unshipped the smallest rocket engine and fastened it securely to the rear of the raft. I strapped down as many fuel tanks as the raft would hold.
     Then—chuckling to myself—I asked Erna to help me haul the cannon out.
     "The cannon? Whatever for?"
     “To mount at the front of the raft."
     “Are you figuring on meeting space pirates?"
     "I'm figuring on using the cannon as a brake," I told her. We fastened it at the front of the raft, strapped down the supply of cannonballs and powder nearby it. The cannon would make an ideal brake. All we needed was something that would eject mass in a forwardly direction, pushing us back by courtesy of Newton's Third Law. Why waste fuel when cannonballs would achieve the same purpose?

     It took us forty-eight standard Earthtime hours to build the raft. I don't know how many thousands of (719)- Albert days that was, but the little asteroid spun on its axis like a yo-yo, and it seemed that the sun was rising or setting every time we took a breath.
     After I had bound the last thong around the rocket engine, Erna grinned and dashed into the ship. She returned, a few moments later, waving a red flag with some sort of blue-and-white design on it.
     “What's that?"
     “The flag that flew over Macintyre's cabin," she explained. “It's a rebel flag, and we're not strictly insurrectionists, but we ought to have some kind of flag on our ship."
     I was agreeable, so she mounted the flag just fore of the rocket engine. Then we returned to the ship to wait.

     Meanwhile Jupiter swelled bigger and bigger as (719)-Albert plunged madly along its track toward its rendezvous with Jove. If luck rode with us—translated, if my math had been right—we would find Ganymede midway in her seven-plus day orbit round the big planet.
     Time came when the mass detectors in my ship informed me that Jupiter had stopped getting closer and was now getting farther away. That meant that (719)-Albert had passed its point of aphelion and was heading back toward Earth. It was time to get moving.

     “All aboard," I told Erna. “Make sure everything we're taking is strapped down tight—food, fuel, air tanks, cannonballs, flags."
     She checked off as if we were running down meters and gauges at a spaceport. “Food. Fuel. Air tanks. Cannonballs. Flag. All set to blast, Captain."
     “Okay. Get yourself flattened out and hang onto the raft while we blast."
     Blastoff was a joke. I had computed the escape velocity of (719)-Albert at approximately .0015 miles/sec. We could have shoved off with a good rearward kick.
     But we had fuel to burn. "Allons!" I cried, slamming the rocket engine into action. A burst of flame hurled us upward into the night. "A La belle È'toile!" I shouted. “To the stars!"
     The raft soared off into space. Erna laughed with delight. As (719)-Albert slowly sank into the sunset, we plunged forward toward giant Jupiter. The only thing missing was soft music in the background.

     We rode the raft for three days at constant acceleration. Jupiter grew, and grew, and grew, and gleaming Ganymede became visible peeking around the edge of the great planet. Erna became worried when she saw it.
     “Shouldn't we head the raft over toward Ganymede?" she asked. “We're pointed much too far forward."
     I sighed. “We aren't going to reach Ganymede for another couple of days," I said. "We want to head for where Ganymede's going to be then, not where it happens to be right now. Isn't that obvious?"
     “I suppose so," she said, pouting.

     We were right on course. Two days later we were heading downward toward the surface of Ganymede. It was like riding a magic carpet. I controlled our landing with the rockets, while Erna gleefully fired ball after ball to provide the needed deceleration. If Ganymede had had an atmosphere, of course, we'd have been whiffed to cinders in a moment—but there was no atmosphere to contend with. We made a perfect no-point landing, flat on the glistening blue-white ice. Lord knows what we must have looked like approaching from space.
     We had landed a hundred miles or so from the nearest entrance to the Ganymede Dome. I was dourly considering the prospect of trekking on foot, but Erna was certain we had been seen, and, sure enough, a snowcrawler manned by three incredulous colonists came out to fetch us. I never saw human eyes bulge the way those six eyes bulged at the sight of our raft.

     It's a funny thing about General Macintyre's log cabin. Despite Erna's careful diagram, the cabin never got put back together. It seems that the people of Ganymede decided it was of no great value to display the cabin of some Venusian rebel when they could be showing an item of much more immediate associations for Ganymedeans. So they wouldn't let Ema take the raft apart, and I had to buy myself a new rocket engine. You can see the raft in the museum on Ganymede, any time you happen to be in the neighborhood.

From DELIVERY GUARANTEED by Robert Silverberg (1959)

(ed note: The colony world of New Finland has been invaded by nasty troops from a nasty colony. Mac and Joslyn are a married couple in the galactic survey service of the League, and are in the only starship positioned to sneak into New Finland's solar system before the enemy completes their anti-starship missile network. Mac and Joslyn have to infiltrate the captured planet and deliver plans for an experimental teleportation device that will deliver 5,000 Legion troops into the heart of enemy territory.)

"Against that, the only thing making us go in and risk our lives for strangers      is the feeling that we have to do it." I paused. "And it's enough, I guess. Thanks to the sense of duty they've bred and beaten into us. And I know what you mean about having no choice."
     "And now that it's all out of your system, let's go finish the go-cart," Joslyn said, rumpling my hair.

     The "go-cart" was what was left of the torpedo we had started with. Joslyn and I had pulled down the entire nose section. I had been working on installing a crash-couch onto the front end of the torp's motor housing while Joslyn pulled the guidance system out of the nose section and hooked it back up to the decapitated torpedo. She left off the frills: it would pick up a downloaded trajectory from Stripes's guidance system and run with those numbers: that was it. The control panel was one button marked "ON."

     The crash-couch looked more like a lawn chair, and folded up like one, but it was extremely strong. The J.M. carried about ten of them, in case she ever had to carry passengers.
     The go-cart was the key to our grand plan for getting an agent (me) down to talk with the locals and arrange for the little matter of the transmission of 5,000 combat troops.

(ed note: Mac leaves the J.M. survey ship in an auxiliary spaceship, the Stars & Stripes. Strapped to a cargo clamp is the go-cart.)

     The worst of it all was the boringness of space travel. There is very little to do on a ship by yourself. Added to that was the tension of all the unknowns ahead of me; it was not a pleasant time. Mostly I studied my Finnish.
     Finally, it was over. One hundred eighty degrees around the sun from the J.M., I arrived at the vicinity of New Finland, albeit travelling at a great relative speed. I couldn't use Stripes' engines to slow down: Joslyn and I didn't want the aux ship to get within two million klicks of the planet. Closer, and there was a chance someone might spot her. I had to abandon ship. That was what the torp, the go-cart, was for. I was to jump ship, climb into the fold-out crash couch, and ride the torp's motor in. Stripes would continue on her present course for a long while yet, until she was far enough from New Finland to use her fusion engine without risk of detection. Then she would turn back toward the sun, going into a solar polar orbit that would keep her in line of sight of both New Finland and the Joslyn Marie for many months, if she was left undisturbed by the Guardians (the bad guys). While in line of sight, Stripes could serve as a relay station for laser messages between Joslyn and myself.
     I had an interesting trip from there on. I collected all my gear and checked my suit over a half dozen times. I would be counting on it for a long while. Then I gave the guidance pod on the go-cart a download from Stripes' astrogation computer. Now the torp's computer would know where it was and where I wanted it to go.

     Before I abandoned Stripes, I wrote Joslyn a brief note. Nothing meaningful. But if I got myself killed, as was very likely, and Joslyn recovered the aux ship, I wanted her to have something, some words, that had passed from my hand to hers.

     And then I was out the hatch. It took some huffing and puffing to get my oversized, pressure-suited self, my maneuvering backpack, and my equipment bag onto the go-cart in such a way that it would be properly balanced in flight. When I had, I stretched a finger toward the cargo-clamp release button, and a rattling vibration told me I was free of the ship. I reached a little farther and shoved hard against the ship's hull. The go-cart and I drifted slowly away. I checked the chronometer in my suit's helmet-an hour until I had to push that single button marked "ON" and get this show on the road. Plenty of time for Stripes to get safely distant. I hadn't shoved with great precision: the go-cart was tumbling gently. It didn't matter. I spent the hour watching the gently receding Stripes drift around my field of view, to be replaced by a splendid view of New Finland and her single large natural moon, Kuu. I was too far away for any hope of spotting Vapaus, which was my eventual target. I was lucky in that the sun remained pretty much at my back as I tumbled.
     And then it was time. I pushed the "ON" button, and the torp's gyros began to whir busily. I felt the vibration through my suit. The guidance pod spotted New Finland and set itself up to home in on the planet.

     Without any warning, the engine lit up ten gees at my back and that go-cart moved! It was a short life but a merry one, and the torp engine died as suddenly as it had opened up. Without the burn, I would be following Stripes as she slowly drifted away from the planet. Now I was moving straight for New Finland, and at a pretty good clip. The torp began to rotate itself along its long axis for the retro-burn about 30 hours later. If the retro-burn didn't work, I was going to drop right into the atmosphere and burn up. I had enough confidence in the torp that I wasn't worried, but I had something else that annoyed me enough to avoid boredom: I was now pointed straight at the sun, almost forced to stare at it. I slapped my sunshield down and set it to OPAQUE. Otherwise I would have been blinded.
     I had a good bit of waiting to do. I spent part of it chewing over the plan Joz and I had cooked up for my getting inside the hollowed-out asteroid world Vapaus.

     The 30 hours slid away in studying, sleeping, and worrying. Riding with the helmet opaqued was tough: besides the readouts and telltales inside my suit's collar, there was nothing to see. The blacked-out glass of the helmet was dark and featureless, inches from my face. I hung in the middle of space with only my suit between me and infinity, feeling claustrophobic. That made my worrying all the more effective. A dozen times I reached for the black-out control to lighten the helmet so I could see, and just barely talked myself out of it each time. The sun would have blinded me. Period. That was a convincing argument, even under the circumstances.
     The torp was programmed to bring me about 100 kilometers off Vapaus and then fire its motor not quite enough to bring me into orbital velocity. My backpack unit would make up the difference, and the torp was to fall on into New Finland's atmosphere and burn up.

     I was asleep when the burn came, dreaming about flying Stars through a coal-black cave, trying to get to Joslyn, though she fell farther and farther away. I came awake badly disoriented, having a lot of trouble sorting out the dream from the reality, until I remembered it was okay to kill the blackout control now. The planet of New Finland popped into existence in front of my face, and then slowly swung away and got behind me. Its job done, the guidance system had shut down, and the torp was tumbling without gyros.
     I wanted to get away from the go-cart as soon as I could; I wasn't eager to share its ride down to the surface. The backpack unit, comprised of a maneuvering jet unit and life-support system, was stowed underneath the crash couch, along with other equipment I expected to need. I pulled the hose connections that had attached me to the life-support unit, as they were snaked through the crash couch, wrestled myself free of the couch's straps, and pulled my gear out from beneath it.
     Working as fast as I could, I shoved clear of the torp, dragging the gear with me. I wriggled into the backpack unit and re-attached the hose connections, then swung down the control arms and got busy with the joystick. I found Vapaus's radio beacon, got a reading on it, waited a minute, and took another reading. The backpack's guidance system was about as sophisticated as a wet finger in the wind, but the two readings were enough to give me a general idea of which direction to fly. I hosed out some fuel and watched the go-cart drift away, headed for oblivion in the upper atmosphere.

From THE TORCH OF HONOR by Roger MacBride Allen (1985)

(ed note: Bruce and his father Dr. Rhodes are part of an expedition exploring Saturn's rings. Dr. Rhodes manages to maroon himself somewhere in the ring system {meteor damages his rocket-boat's atomic fuel distributer}. Bruce goes looking for him and gets marooned as well. Eventually he manages to contact his father on the radio)

      Now he opened the radio again. It was a few minutes before he could again contact his father.
     "I have the distributor here. It is O.K. What shall I do now?"
     His father's voice came back. "Listen carefully. Take down my location. You must try and come to me, and bring the distributor. It is our only chance to get back. You must bring it to me. If I have this one part, we can both return in my craft. My own ship is otherwise all right, but the distributor was faulty, and broke completely. I have not been able to repair it."
     Bruce announced his readiness to try anything. He could not imagine how it would be possible for him to go to his father without a ship, but he felt that one might as well try anything. "How are you fixed for food and air?" he asked.
     "I've a little, but not much," came his father's reply. "You have no time to waste. Besides, judging from your radio position, I am catching up with your position on the outer ring. You must not let me pass you or you will never catch me. You must start now. Listen…"
     He talked for several minutes, giving Bruce directions as to how to proceed. Bruce opened his radio for one last second: "O.K. I'm on my way. Keep talking so I can locate you."
     He snapped his sender shut. His father's voice was now audible over his helmet phones, though no longer understandable in the uproar of static and electronic interference. But it was understood that his father's voice was to serve as a guiding beam for him to follow, much as an airplane follows a radio beam to its airport.
     Bruce stuffed the spacious pockets of his space suit with as much food as he could stow. He carefully strapped the little boxlike fuel distributor to his belt. He pulled the seat out of the cockpit, unscrewed the three small oxygen tubes stowed there, strapped them to his back.
     Now, with a wrench in hand, he climbed to the back of the small boat, tore open the cowling and plates, exposing the entire innards. The long tubes of fuel stood exposed, the exhaust valves, the smashed parts, reams of wiring in many colors. He found the tube he was looking for, a yard-long plastic cylinder, fitting into the mixing chamber. This he carefully unscrewed, making sure to avoid any chance of the cylinder's contents escaping. He lifted this cylinder clumsily out of the boat, stood it on the ground, and easily leaped down to join it.
     Taking part of the nylon ropes that held his boat to the ring-particle's surface, he turned the cylinder valve end down, and strapped it to himself, so that he straddled the thing like a witch on a broom, his feet hanging down. (in reality it would be more like wrapping ones arms and legs around a vertical telephone pole. Because "down" is in the direction the exhaust travels)
     Looking briefly around, looking at the small rocket boat which was now beginning slowly to drift and roll with the motion of the little moonlet, he gazed upward.
     The great glowing mass of Saturn filled the sky, bathed everything in a golden glow. Against its surface he could see the thick black line of the next ring inward.

(ed note: Bruce travels towards his father's location, using his legs to jump from ring fragment to ring fragment)

     At long last he saw that the edge of the outer ring was at hand. He made one final moonlet, and stood now, silently staring.
     The tiny worldlet beneath his feet was shining softly in the Saturn light. Its horizon curved away a few feet from where he stood. Beneath him he could look down into a bottomless pit in which swam countless lights, beyond which he could see the vague face of one of Saturn's large moons. Looking out to his sides, he seemed to feel himself standing on a large flat plain, stretching shining and soft across the sky, the illusion of solidity caused by the unending parade of millions and millions of fragments, reduced by the processes of the ages to a certain unison of direction and speed.
     Above him shone the huge round bulk of Saturn, a molten sea, its belts of swirling gas like veils coneealing a mystery that none might ever look upon. And before him, seeming but a step away, was another ring, a flat circular platform to his eye, darker than his ring, but still glowing silent and untenanted in the sky. Between him and that other platform seemed but a short distance, a narrow gap over starry depths.

     Bruce knew that this was a dangerous illusion. This was no narrow step, no close-lipped abyss. This was a space that was not a few hundred feet or even a few miles wide. It was a gap two thousand two hundred miles across! It was like the distance from New York to Denver, taking the familiar measurements of his homeland's geography as a guide to understanding.
     Could a man cross such a space in one leap?

     The answer, astonishingly enough, was yes. Bruce understood that. That was the trickery of outer space. If you weighed nothing, if you start yourself in motion, and there is nothing to slow you down, no air to push against, no force to pull you back, then you will continue to move with your initial speed forever. Forever, that is, until you do hit something, or until something pulls you to it.
     That was not the problem. If Bruce leaped now, he would eventually fall into the next ring. But the question was: when? With all the strength he could muster, he would probably still take many, many days to fall across that gap—even though great Saturn would actually be drawing him also, speeding him slowly toward it. In that time, his air would foul, his suit's heat be lost beyond the power of his small belt battery to restore it, he would starve.
     He had to cross the belt fast, at space-ship speeds. He had to speed up to be able to come alongside the particles of that ring, which were moving a good deal faster than the ones he stood on, whose speed was now his own. He had to aim himself to hit the one spot in that vast ring where his father waited, to hit it without delay, in a matter of hours, as few as possible.

     His father had told him of a way. No man in all the history of space travel so far had ever needed to try it. But now Bruce poised himself. Ready, he said to himself. Set, his mind ordered, and then, Go!
     He braced himself, grasped the long cylinder from his boat firmly, and hurled himself upward and outward into the gap between the rings, into the empty space that separated them. Astronomers back on Earth had named this gap. It was known to them as Cassini's Divide, after the ancient astronomer who had first detected it. And now Bruce was moving into this Divide alone, moving across it.
     He was a lone figure, a strange one to try to cross such a distance. A bulky, airtight, electrically warmed coverall was his space suit, fitting him like a loose pair of jumpers. On his feet small metal soles provided magnetic attraction when needed. A pack on his back housed his tiny atomic-activated battery, which supplied the current for his suit, the power for his radio. Twin tubes forming part of the pack supplied his oxygen, fitting into a marvelous little purifier drawing in and revitalizing the air steadily. Despite this device, the power of the suit's air supply was strictly limited, in a day or so the amount of poisonous elements in his air would be more than could be removed, then suffocation would set in.
     On his head a glassine, metallically reinforced helmet allowed him vision in all directions. A visor on the front could be opened if necessary when there was air pressure on the outside. A small but powerful portable atom-radio made up a flat pack attached to the suit's chest, and its phones were built into the helmet. The wide pockets of his suit were bulging with the fragments he had taken from the ring-moonlets. A container on his belt held the fuel distributor and a sack of sandwiches. A huge canteen swung from another part of his belt.

     But it was the cylinder which now dominated the picture. Bruce was astraddle it, and the cylinder head was down. As he moved away from the ring edge, outward into the void, heading on toward the bulk of Saturn, Bruce manipulated the valves on this cylinder. As he turned one, he felt a vibration in his finger tips, and a sudden thrust to his body. He felt as if something were dragging him forward, felt the cylinder seem to struggle in his hands as if trying to escape.
     The cylinder contained inert gas, under great pressure. This was used in the rocket jets to dampen the inner effects of the blast and to occupy the fuel tank space left empty by the exhaustion of fuel. The gas was not fuel itself, but it was necessary to the safe and practical application of the atomic explosive fluid used.
     But a rocket operates on a very simple principle, and even a flow of gas from a cylinder or a balloon can move the object it is escaping from if the weight is low enough. As a small boy, Bruce had seen toy balloons whiz around a room when they sprang a leak and the gas whizzed out of the side. In effect, this cylinder, packed with tremendous quantities of gas under great pressure, was such a balloon, tremendously more powerful.
     Bruce had no weight. The release of the gas from the cylinder, forced out through a tiny nozzle, created a genuine rocket effect, no different in any way from the principle used in the space ships. This cylinder's thrust held to Bruce's body, directed by Bruce, made the boy a miniature space ship in fact, if not in outward appearance.

     He directed his motion toward the point in the ring from whence his father's voice came. Or rather toward a point ahead of it, knowing that by the time he reached that point, there his father's ring-particle would be. The constant thrust of the cylinder, as its gas drove through it, created a steady acceleration. A fast one, ever faster (as the gas is expended the mass goes down so the acceleration increases). If the gas held out, Bruce should be able to cross that Divide at a speed almost equal to that which his little rocket boat could have given him.
     Onward he floated, the cylinder vibrating in his hands, the radio squealing, his father's voice becoming ever clearer in his ears. Before him the huge hemisphere of Saturn loomed; he seemed slowly falling toward it. Behind him the inner edge of the outer ring was rapidly drawing away, its surface flattening out, glistening. Above him he could see the face of one of Saturn's moons, mottled in white and gray, as the sunlight was reflected from its barren valleys and mountains. On all sides, beyond Saturn, there glowed the millions of brilliant pin points that were the stars beyond the solar system, the unimaginably distant suns. It would be hours, Bruce knew, before he could reach his destination, in spite of his now terrific speed. He clutched the cylinder, stared ahead, listened to the sound of his father's voice amid the humming of his radio.
     "So I was waiting here, hoping that someone would come from Mimas. I am glad it was you, Bruce, although it was a dangerous thing to do. If you can reach me, soon I hope, we will be able to get away and return. I have enough fuel, but my air is low, and I have not eaten in ten hours."

     Bruce gritted his teeth. He was nearing the edge of the inner ring. He saw that his speed was still not quite that of the moving particles, which he could now detect. He increased the flow, twisted his body so that the cylinder moved and now he was speeding up, moving alongside the ring.
     In a short while he was running up close to the edge of the inner ring. He could see the moonlets, close-packed, one upon another rolling through the heavens in their unending tight parade. For the most part they did seem darker than those he had noticed before.
     He listened as his father's voice grew louder, despite the increase of the humming and static as he was getting nearer to the moonlets. He moved along, faster than the particles, straining his eyes to find one which would be brighter than the rest. It was like trying to find a needle in a haystack, but fortunately this particular needle was calling out to him.
     On and on he moved, his eyes wearying of the constant strain. Now and again he imagined he would see some brighter body among those visible at the edge, but each time as he neared it he realized that the radio voice was coming from beyond it.
     He glanced down at his cylinder of gas, and suddenly realized that it was getting low, that the dial which registered its internal pressure was nearing the zero mark. He knew he had only a few more minutes left to him.
     Now he thought he saw another little moonlet, different in texture from the others. He moved again toward it, angling inward. And then he noticed a tiny spot against its shining surface, the tiny bullet shape of a rocket boat. And as he rushed toward it, he saw a tiny man-figure standing next to it, waving his hand.
     There was a strange change in Bruce's body pressure. He seemed suddenly held back. He looked down. The gas had stopped. The cylinder was empty.

     Bruce was still moving. In space there was nothing to stop him; but he had calculated on the continued extra drive of the cylinder to bring him to the surface of the moonlet. Now that that power had died, he saw that he would drift past, miss the surface by several feet—but that would be enough. There was nothing for him to push on, no way he could see to bring him that extra distance or to alter his direction of free float.
     He waved his hand wildly, pointed energetically at the cylinder, hoping that his father would understand his predicament. He heard his father's voice, "What's wrong? Can't you make it?"
     Bruce waved more. He couldn't attempt to speak to his father yet, the interference would have drowned out his weak space-suit radiophone which was designed only for conversing over very short distances. He waved to the cylinder again.
     His father's voice came on again. "Oh! The thing's empty! You can't get any more power. Well, now … listen to me. There's still one more thing you can use that cylinder for, and you'll have to do it right. First, unstrap it from yourself."
     Bruce showed he understood by doing so, wriggling around clumsily and freeing himself from the long gas container. All this while he was drifting after the ring-particle, nearing it but at a wider and wider angle.
     When he had untied it from his suit and was holding it to him by his hands, Dr. Rhodes spoke up, "Do this right and do it carefully. Grab the cylinder, swing it in the direction opposite that to which you want to go. At the proper moment, when you're closest to me, throw it away from you as hard as you can. This should have the effect of pushing you in the opposite direction, according to the laws of rocketry, based on an equal reaction for every action."
     Bruce understood this. He followed instructions, swinging the yard-long plastic container around until his own body was directly between the moonlet and it. He continued his free drift, until he saw that he would get no closer to the surface. At that point, he shoved the cylinder away from him with all his might.
     The empty container shot away fast. Bruce himself moved away from the point of the throw in the opposite direction, but much slower, for he was many times bulkier than the cylinder. But it was enough. In a few more minutes his feet brushed against the polished marble surface of the moonlet. His father caught him, drew him down, and they clung together in mutual relief and joy.

From THE SECRET OF SATURN'S RINGS by Donald Wollheim (1966)

(ed note: the evil Duke Edwin Cairncross is plotting to overthrow the galactic emperor. At his covert asteroid base Port Asmundsen he has amassed a warfleet and munitions. Our hero, secret agent Dominic Flandry, uncovers the plot and is planning a operation to destroy Port Asmundsen. He sneaks into the system in his starship the Hooligan with only his faithful manservant/armsman Chives and lady Miriam who alerted Flandry to the plot.)

      Dark, cold, silent, every system turned off or throttled down to bare minimum, Hooligan drifted swiftly outward in a hyperbolic orbit. It would take her close to the moon, past the hemisphere opposite Port Asmundsen. The chance of her being observed was therefore slim, no matter how many were the instruments standing sentry. If a radar beam did happen to flick her, she ought to register as a bit of cosmic scrap. No natural meteoroids attended Niku, but an occasional rock must go by on its way through interstellar space; also, during centuries of human occupation, considerable junk must have accumulated around the planet
     (Flandry said) “Chives and I are going to sneak our warheads in.”
     (lady Miriam said)“Why can’t Hooligan retrieve you?”
     “Too risky. She’s got to keep in free fall till the base is destroyed, if it is; and afterward, whatever craft were in space will still exist, revenge-hungry. Too many unforeseeables. A computer lacks the judgment to cope with them.”
     I read your thought, passed through him. Spacesuit impellers can’t transport us across some twenty million kilometers—alive, anyway. The odds aren’t much better if we ride a missile, especially considering the radiation belt we have to traverse. Anyhow, we’d doubtless be detected by a ducal ship. Or supposing, fantastically, we did make it, the militia will be ransacking every site where Foundation personnel are, and quizzing them under narco, to make lying impossible. How could we hide?

     An airlock opened. Flandry and Chives stepped forth into space.
     Sharing the orbital velocity of the ship, they did not leave her at once. The hull seemed to lie unmoving, agleam in savage sunlight.
     Chives’ voice came through his earplugs: “The weapons are emerging, sir.” Bulky in his suit, but his withered green countenance visible through the helmet plate, the Shalmuan flitted ahead.
     Hooligan had discharged a missile on minimum impetus. The five-meter-long cylinder moved slowly off, drive tubes quiescent. Chives caught up. Behind the blunt, deadly nose, he welded a cable which secured harness for two; near the tail he fastened a tow attachment with an electrically operated release; forward again, he installed a control box which would take over guidance. Not everything had had to be made from scratch; Flandry had had a few occasions in the past to use a torpedo for an auxiliary. Banner’s sled was not adaptable to that, being underpowered and intended for planetary conditions.
     The man himself was equally occupied. A cargo handler had cast forth half a dozen warheads which had been removed from their carriers. The rounded cones, a meter in height, were linked by steel cords; the ensemble tumbled leisurely as it moved, like some kind of multiple bola. But the gaucho who would cast it was after big game. Within each gray shell waited atoms that, fusing, could release up to a megaton. Flandry went among them, pushing, pulling, till he had them in the configuration he wanted. Chives steered the missile close. Together, he and the Terran prepared the warheads for towing.
     The task was lengthy, complex, beset by the special perversity of objects in free fall. By the time it was done, Flandry’s undergarment was wet and reeking. An ache in every muscle reminded him that he was no young man. Chives trembled till it showed on his suit.
     “Squoo-hoo, what a chore!” Flandry panted. “Well, we get to rest a while, after a fashion. Come on, into the saddle, and do you know any ancient cowboy ballads?”
     “No, sir, I regret I do not even know what a cowboy is,” his companion replied. “However, I retain those arias from Rigoletto which you once desired me to learn.”
     “Never mind, never mind. Let’s go.”
     Astraddle on the cylinder, held by a reinforced safety web, the control box under his hands, Chives at his back, Flandry cast a final glance at Hooligan. In the course of making ready, he had wandered from her; she looked minute and lost amidst the stars.

          Acceleration tugged him backward, but it was mild and he could relax into his harness. A look aft assured him that the warheads were trailing in orderly wise at the ends of their separate lines. From a clasp at his waist he took a sextant. That, a telescope, and a calculator were his instruments, unless you counted the seat of his pants. He got busy.

     His intention was to round the moon and make for Port Asmundsen. This would require that he fall free during the last part of the trip; grav tubes radiated when at work. It must needs be a rather exact trajectory, for at the end he’d have seconds before the defenses knew him and lashed out. Well, he’d correct it once the base hove in view, and he’d done a fair amount of eyeball-directed space maneuvering in his time. The “broomstick” you rode when playing comet polo was not totally unlike this steed…
     Having taken his sights, run off his computations, and adjusted his vectors, he restowed the apparatus.

     Port Asmundsen appeared on the limb of Elaveli. At this remove, the telescope picked out hardly more than a blur and a glitter, but Flandry got his sight and did his figuring. He made finicky adjustments on the controls. “Hang on to your bowels, Chives,” he warned. “Here comes the big boost.”
     It was not the full acceleration of which the missile was capable. That would have killed the riders while it tore them out of their harness. But a force hauled them back for minutes, crushed ribs and flesh together, choked off all but a whistle of breath, blinded the eyes and darkened the awareness. After it ended, despite the gravanol in him, Flandry floated for a while conscious only of pain.
     When he could look behind him, he saw the Shalmuan unrevived. The green head wobbled loosely in its helmet. Nothing save a dribble of blood-bubbles from nostrils showed Chives was not dead; the noise of his emergency pump, sucking away the fluid before he should choke, drowned shallow breathing.
     With shaky hands, which often fumbled, Flandry took a new sight and ran a fresh computation. No further changes of trajectory seemed called for, praise fortune. To be sure, if later he found he’d been wrong about that, a burst of power at close range would give him away. But he allowed himself to hope otherwise.
     There’d be little to do but hope, for the next hour or so. His velocity was high, and Elaveli would add several kilometers per second to it, which helped his chances of escaping notice. Yet he couldn’t arrive too fast, for last-moment adjustments would certainly be needed and his reaction time was merely human.
     The death-horse plunged onward. Port Asmundsen took form in the telescope. Flandry’s mind filled out the image from his recollection of pictures he had studied at Wainwright Station—none recent. A cluster of buildings occupied a flat valley floor surrounded by mountains. Most was underground, of course. Ships crowded a sizeable spacefield. Installations were visible on several peaks, and he felt pretty sure what their nature was.

     No doubt the base had a negafield generator. If his missile was identified in time, it would suddenly be confronted by a shield of force it could not penetrate, except with radiation that would do negligible damage. If it did not detonate, it would fall prey to an energy beam or a countermissile, fired from beyond the screened area. Flandry was betting that it would not be noticed soon enough.
     It and its tow were just a cluster of cold bodies, smaller than the smallest spacecraft, in swift motion. A radar might register a blip, an optical pickup a flick, but the computers should dismiss these as glitches. He had hypothesized that the defenses were served chiefly by computers. Cairncross’ men, especially his experienced officers, must be spread thin; he couldn’t raise a substantial body of reservists until he was ready to strike, without revealing his hand. Port Asmundsen held mostly workers. (Flandry had no compunctions about them; they knew what they were working for.) Of naval personnel there, few if any could have more than a theoretical knowledge of war.
     Moreover, not even a commander with battle ribbons would likely have imagined this kind of attack. Missiles were launched from warcraft, and none which didn’t serve the ducal cause were known to be anywhere near. The raid on Dukeston would have brought a general alert. But the assumption was natural that Hooligan was bound straight home to tattle. Cairncross would have ordered a search by such vessels as had the appropriate capabilities—which meant that those vessels were not on sentry-go around Elaveli.
     We’ll find out, rather soon, how right I am.

     His attack was from the direction of the sun, whose brilliance torrented out of blackness, over knife-sharp heights and crags, across ashen valley and crouching buildings and the gaunt forms of ships. They grew below him, they reached, they reeled in his vision.
     “Ya-a-ah!” he screamed, and gave a final burst of power. His thumb pushed a button. The tow attachment opened and released the warheads. They swept on. Flandry spun a pair of dials. The missile surged, the leap went through his bones, it was as if he felt the metal strain against its own speed.
     “Don’t look down!” he yelled (or the flash from the nuclear warheads will fry your eyeballs). Himself he peered ahead. His groundward vector was enormous. He was fighting it with as much thrust as he could stand while remaining wholly awake, but there was no telling if he would clear the mountain before him.
     Hai, what a ride! Here comes the Wild Huntsman!
     The mountain was twin-peaked. With all the skill that was in him, Flandry sought the gap between. Cliffs loomed dark and sheer. Suddenly they blazed. The warheads had begun to strike.

     He saw the mountain shudder and crack. A landslide went across it. Another burst of reflected lividness left him dazzled. The first flung shards hurtled incandescent around, and the first night-like dust.
     Somehow he got through. A precipice went by within centimeters, but somehow he did not crash. And he was beyond, falling toward barren hills underneath but more slowly for every furious instant. He might … he might yet … yes, by Satan, he would clear the horizon! He and Chives were returning starward.
     When he knew that, he stared back. A pillar of murk rose and swelled, up, up, up above the shaken range. Lightnings lanced through it. That dust would quickly scatter and settle in airlessness, apart from what escaped to space. Radioactivity would poison the stone soil for years to come. The molten-bottomed craters in the valley floor would congeal around what twisted, charred fragments were left of Port Asmundsen—a terrible warning which no future powermonger would heed.
     Well, but there was sufficient evidence for a properly equipped investigative team. No question survived as to what had been hatching here. Flying, Flandry had seen camouflaged portals torn open by quake and collapse; the glare of his bombs had bounced off torpedoes, artillery, armored vehicles, nothing that an honest provincial governor needed or would have concealed.

From A STONE IN HEAVEN by Poul Anderson (1979)

      Not far from the station was a veritable museum of astronautics, a floating graveyard of ships that had seen their day and been withdrawn from service. Most of them had been stripped of their instruments and were no more than skeletons. On earth, of course, they would have rusted away long ago, but here in vacuum they would remain bright and untarnished forever.

     Among these derelicts were some of the great pioneers—the first ship to land on Venus, the first to reach the satellites of Jupiter, the first to circle Saturn. At the end of their long voyages, they had entered the five-hundred-mile orbit round earth and the ferry rockets had come up to take off their crews. They were still here where they had been abandoned, never to be used again.

     All, that is, except the Morning Star. As everyone knows, she made the first circumnavigation of Venus, back in 1985. But very few people know that she was still in an excellent state of repair, for the apprentices had adopted her, made her their private headquarters, and, for their own amusement, had got her into working condition again. Indeed, they believed she was at least as good as new and were always trying to "borrow" enough rocket fuel to make a short trip. They were very hurt because no one would let them have any.

     Commander Doyle, of course, knew all about this and quite approved of it. After all, it was good training. Sometimes he came over to the Morning Star to see how things were getting on, but it was generally understood that the ship was private property. You had to have an invitation before you were allowed aboard. Not until I'd been around for some days, and had become more or less accepted as one of the gang, did I have a chance of making the trip over to the Morning Star.

     It was the longest journey I had made outside the station, for the graveyard was about five miles away, moving in the same orbit as the station but a little ahead of it. I don't quite know how to describe the curious vehicle in which we made the trip. It had been constructed out of junk salvaged from other ships, and was really nothing more than a pressurized cylinder, large enough to hold a dozen people. A low-powered rocket unit had been bolted to one end, there were a few auxiliary jets for steering, a simple air lock, a radio to keep in touch with the station—and that was all. This peculiar vessel could make the hop across to the Morning Star in about ten minutes, being capable of achieving a top speed of about thirty miles an hour. She had been christened The Skylark of Space, a name apparently taken from a famous old science fiction story.

     The Skylark was usually kept parked at the outer rim of the station, where she wouldn't get in anybody's way. When she was needed, a couple of the apprentices would go out in space suits, loosen her mooring lines, and tow her to the nearest air lock. Then she would be coupled up and you could go aboard through the connecting tube, just as if you were entering a real space liner.

     My first trip in the Skylark was a very different experience from the climb up from earth. She looked so ramshackle that I expected her to fall to pieces at any moment, though in fact she had a perfectly adequate margin of safety. With ten of us aboard, her little cabin was distinctly crowded, and when the rocket motor started up, the gentle acceleration made us all drift slowly toward the rear of the ship. The thrust was so feeble that it made me weigh only about a pound, quite a contrast to the take-off from earth, where I could have sworn I weighed a ton! After a minute or so of this leisurely progress, we shut off the drive and drifted freely for another ten minutes, by which time a further brief burst of power brought us neatly to rest at our destination.

     There was plenty of room inside the Morning Star; after all, she had been the home of five men for almost two years. Their names were still there, scratched on the paint work in the control cabin, and the sight of those signatures took my imagination back almost a hundred years, to the great pioneering days of spaceflight, when even the moon was a new world and no one had yet reached any of the planets.

From ISLANDS IN THE SKY by Arthur C. Clarke (1952)

Lunar Escape System

This is an emergency lunar escape vehicle concept, in case an Apollo Lunar Module crashed upon landing. It was designed to be assembled from various parts canibalized from the wreck. Note that in the two-man version, the pilot gets an acceleration chair, but the poor second astronaut is slung under the chair by straps. You can read more about this here, and here.

Space Pod

A space pod is a small pressurized vehicle with one or more waldoes or mechanical arms. They are often used for space construction and maintenance. In the movie 2001 A Space Odyssey, they were referred to as "EVA pods." In Wernher von Braun and Disney's Man In Space series, they were called "bottle suits." They are also known as "closed-cabin cherry picker", "manned autonomous work system", and the ever popular "man-in-a-can."

One of their main advantages over a soft space suit is that they solve the depressurization problem. Another is they can be radiation-hardened, to protect the astronaut from cosmic rays and solar storms.

There are some designs that carry more than one astronaut, these are in the gray area between space pods and space tugs.


(ed note: this is from a study performed by the Lockheed company under contract from the Aero Propulsion Laboratory of Air Force Systems Command)

Shuttle Concept Analysis

Preliminary Design


“Juhani, suit up and get ready to go over there in the Flexcraft. Fuji can handle monitoring the engines while you’re away.”

Janhunen lowered his visor, sealing his spacesuit, and moved to the airlock separating the ship from the attached Flexcraft. It took another twenty minutes to cycle the airlock and get him settled into the small confines of the spacecraft and perform the necessary systems checks.

The Flexcraft was a hard-skinned miniature spacecraft that resembled a deep-sea submersible more than a spaceship. The one-person vehicle was designed to allow its occupant to leave the main spacecraft in shirtsleeves or spacesuit and perform almost any repair or assessment that could be accomplished on a traditional EVA—only better. Janhunen stood in the Flexcraft with only his head and arms visible through the 360-degree glass dome on top. On each side of the Flexcraft were two manipulator arms, each equipped with a different grappling fixture or manipulator. Two of the arms terminated with what resembled human hands, complete with opposable thumbs. The upper arm on the right side came with a pincer instead of a hand; the upper left arm resembled a Swiss Army Knife with its multiple tool options that included screw drivers, knives, a corkscrew and at least four additional custom wrench fittings designed to work with various spacecraft subsystems that might need repair from outside the ship.

The Flexcraft flew untethered using cold gas impulsive thrusters that were now taking Janhunen away from the Resolution and toward the Artifact. Chris could see that Janhunen wasn’t taking full advantage of the comfort afforded by the Flexcraft—he was in his EVA suit with the helmet on and locked into place. Janhunen was controlling his flight using the Flexcraft’s version of a virtual control panel, which made him look like an orchestra conductor, sans baton.

From MISSION TO METHONE by Les Johnson (2018)

Jameson turned back toward the repair rig. The two lobsters, bright orange against blackness, were maneuvering themselves into position, getting a helpful nudge or two from the men swarming around them. A repair lobster was nothing more than a simple cylinder with a plastic bubble for the head of its operator at one end. It got its name from the two big claw-like waldos at the forward end and the twin rows of smaller specialized limbs down its ventral surface.

One of the lobsters anchored itself on the Callisto lander’s hull and grasped the embedded landing foot. It tugged gently, trying to do as little further damage as possible. The leg came free. There was a little frosty explosion of particles of trapped air. A couple of space-suited men took charge of the damaged leg and ferried it back to the repair frame. One was Chinese, one American. Jameson grinned without humor. Even the garbage detail had to be bi-national.

The other lobster brought over a replacement leg, an articulated metal lattice five meters long, with the flat mesh pad of the landing foot at one end. Swimming behind it was a four-man crew with laser cutting torches.

From THE JUPITER THEFT by Donald Moffitt (1977)

I'm back to trying to put together some semi-realistic design for near-future space flight. In this case, I'm mainly trying to tackle a couple of problems. The first is the restrictions put on by current EVA technology. There's no such thing as being able to put on your spacesuit, go out the airlock and deal with an emergency these days. A minimum of about 20 hours of slow decompression and prebreathing pure oxygen is required before anyone goes out into space. Thats because the cabin environment of the Space Station, and the Shuttle is oxygen/nitrogen at sea level pressure, while the suits operate with pure oxygen at 5 p.s.i. They do that because, with present, vintage 1980 space suits, the arms and legs become impossible to bend if the pressure is any greater. The other problem is radiation shielding. For long stays outside, or any meaningful work beyond the Earth's ionosphere, the present suits just have inadequate radiation protection.

The potential solution is MAWS. It will have the same internal pressure as the station, or whatever long duration habitat we have in the future, because it doesn't have flexible joints. Instead it uses a couple of miniature versions of the station's robot arm. Its possible to put much better radiation shielding around MAWS, too. Probably the first exploration of asteroids or moons of Mars will be done in something like this design.

So this is the baseline look of the MAWS, as loosely worked out by NASA. Should it have a second set of heavier arms? Where would EVA equipment be attached? In general, what do you think of the idea?


Discovery's extravehicular capsules or "space pods" were spheres about nine feet in diameter, and the operator sat behind a bay window which gave him a splendid view. The main rocket drive produced an acceleration of one-fifth of a gravity—just sufficient to hover on the Moon—while small attitude-control nozzles allowed for steering. From an area immediately beneath the bay window sprouted two sets of articulated metal arms or "waldoes," one for heavy duty, the other for delicate manipulation. There was also an extensible turret carrying a variety of power tools, such as screwdrivers, jack-hammers, saws, and drills. Space pods were not the most elegant means of transport devised by man, but they were absolutely essential for construction and maintenance work in vacuum. They were usually christened with feminine names, perhaps in recognition of the fact that their personalities were sometimes slightly unpredictable. Discovery's trio were Anna, Betty, and Clara.

Once he had put on his personal pressure suit—his last line of defense—and climbed inside the pod, Poole spent ten minutes carefully checking the controls. He burped the steering jets, flexed the waldoes, reconfirmed oxygen, fuel, power reserve.

From 2001 A SPACE ODYSSEY by Arthur C. Clarke (1969)

Grumman DC-5 EVA Craft

     Mass at Earth Gravity: 1,387 Kg.
     Overall Diameter: 1.98 m.
     Capacity: One Person Standard; Three Person Emergency
     Propulsion systems: Ten Mk 12 (140 Kgs. Thrust) for major course changes along all axes; Eight Mk 17 (35 Kgs. Thrust) for precision maneuvers; Eight Mk 8 micro-thrusters (10 Kgs.) for low-gravity station-keeping; Five Mk 14 (80 Kgs. Thrust) provide roll; One Mk 37 (500 Kgs. Thrust) for use in emergency.
     Life Support: 12 Hrs. (One Person)
     Radar: Grumman EPS-2D; Long Range; Active Pulse
     Other Equipment: Explosive Bolt Door Separation*; Short-range Object Approach System and Transponder; Complete HAL 9000 Data link System; Automatic Thruster Control; Auto Hover; Eight-Channel communication system; Advanced Manipulator Control System; Two-hour Oxygen Reserve System.
     Notes: The Grumman DC-5 carries can carry little in the way of food and water stocks, due to short life support capacity. A single air conditioning vent is provided.
     Misc. Technical Information: (From Frederick Ordway and the British Interplanetary Association)
     Propulsion: A subliming solid system provides vernier propulsion, wherein the solid propellent sublimes at a constant pressure and is emitted from a nozzle. Such reaction jets will last for long periods of time, have great reliability and use no mechanical valves. The main propulsion system is powered from by storable liquids.
     Mechanical Hand Controls: Selection controls are placed on each side so that the appropriate hand must be removed from the manipulator to select a tool or to park. Selection of a tool returns the arm to the 'park' position, where it leaves the 'hand', then the arm goes to the appropriate tool and plugs in. In doing so, it inhibits the 'finger' controls on the manipulator, so that when the operator returns his hand into the glove he can only move a solid object, not individual fingers.
     Television: It was found possible to produce all-round TV coverage with eight fixed cameras. This, however, did not give a sufficiently accurate picture for docking or selecting a landing space. For this purpose, the field of view can be narrowed or orientated; controls are included for this purpose.
     Normally, the TV link is occupied by the internal camera, so that the parent craft can monitor the pod interior. The pilot can switch in any other camera for specific purposes (survey, etc.) reverting to interior camera for normal work.
     Proximity Detector: This is the safety system with omnidirectional coverage working from the main communication aerials. It gives audible warning when the pod approaches a solid object. This is necessary as a safety measure as the pilot cannot monitor seven or eight TV displays continuously. The system also detects an approach to an object, the speed of which is too high to be counteracted by the vernier thrust settings on the control system. In this event, full reverse thrust is applied, overriding the manual control setting. The system depends upon a frequency modulated transmission and under safe conditions results in a low, soft audible background signal. This continuous signal is considered necessary in order to provide a continuous check on a vital safety system. If the speed of an approach to an object becomes dangerous compared with the distance from it, the tone becomes louder and higher pitched, and, if unchecked, end in a shrill note accompanied by reverse thrust. The system also works in conjunction with a transponder (to the give the necessary increased range) to measure distance from the Discovery.
     Flying Controls: Manual controls are considered necessary both as a standby and for local maneuvers. Two hand control sticks, each with two degrees of freedom and fitted with twist grips, provide the necessary control about six axes.
     Analog information is presented for attitude, heading rate and distance; these can be referred to local ground (for landing, takeoff, etc.), course (which enables the pilot to face forward, head up, on any preselected course, or parent ship (for docking, local maneuvers, etc.) This data has to be presented, as the pilot has to act immediately on them. This is the most easily assimilated display. A variation in full scale rate, which can be applied by the control sticks, is included; this allows the full stick movements to result in any proportion of vernier motor thrust, thus giving a 'fine' control for local maneuvers.

He was nearer to the sun than any man had ever been. His damaged space-pod was lying on no hill, but on the steeply curving surface of a world only two miles in diameter.

Even then, it was still possible for men in the tiny self-propelled space-pods — miniature spaceships, only ten feet long — to work on the night side for an hour or so, as long as they were not overtaken by the advancing line of sunrise.

He was still not quite sure what had happened. He had been replacing a seismograph transmitter at Station 145, unofficially known as Mount Everest because it was a full ninety feet above the surrounding territory. The job had been a perfectly straightforward one, even though he had to do it by remote control through the mechanical arms of his pod. Sherrard was an expert at manipulating these; he could tie knots with his metal fingers almost as quickly as with his flesh-and-bone ones.

He had aimed the pod with its gyros, set the rear jets at Strength Two, and pressed the firing button. There had been a violent explosion somewhere in the vicinity of his feet and he had soared away from Icarus—but not toward the ship. Something was horribly wrong; he was tossed to one side of the vehicle, unable to reach the controls. Only one of the jets was firing, and he was pinwheeling across the sky, spinning faster and faster under the off-balanced drive. He tried to find the cutoff, but the spin had completely disorientated aim. When he was able to locate the controls, his first reaction made matters worse—he pushed the throttle over to full, like a nervous driver stepping on the accelerator instead of the brake. It took only a second to correct the mistake and kill the jet, but by then he was spinning so rapidly that the stars were wheeling round in circles.

Everything had happened so quickly that there was no time for fear, no time even to call the ship and report what was happening. He took his hands away from the controls; to touch them now would only make matters worse. It would take two or three minutes of cautious jockeying to unravel his spin, and from the flickering glimpses of the approaching rocks it was obvious that he did not have as many seconds. Sherrard remembered a piece of advice at the front of the Spaceman’s Manual: "When you don’t know what to do, do nothing." He was still doing it when Icarus fell upon him, and the stars went out.

It had been a miracle that the pod was unbroken, and that he was not breathing space. (Thirty minutes from now he might be glad to do so, when the capsule’s heat insulation began to fail… .) There had been some damage, of course. The rear-view mirrors, just outside the dome of transparent plastic that enclosed his head, were both snapped off, so that he could no longer see what lay behind him without twisting his neck. This was a trivial mishap; far more serious was the fact that his radio antennas had been torn away by the impact. He could not call the ship, and the ship could not call him. All that came over the radio was a faint crackling, probably produced inside the set itself. He was absolutely alone, cut off from the rest of the human race.

It was a desperate situation, but there was one faint ray of hope. He was not, after all, completely helpless. Even if he could not use the pod’s rockets—he guessed that the starboard motor had blown back and ruptured a fuel line; something the designers said was impossible—he was still able to move. He had his arms.

He slipped his fingers into the controls that worked his mechanical limbs. Outside the pod, in the hostile vacuum that surrounded him, his substitute arms came to life. They reached down, thrust against the iron surface of the asteroid, and levered the pod from the ground. Sherrard flexed them, and the capsule jerked forward, like some weird, two-legged insect… first the right arm, then the left, then the right… .

It was less difficult than he had feared, and for the first time he felt his confidence return. Though his mechanical arms had been designed for light precision work, it needed very little pull to set the capsule moving in this weightless environment. The gravity of Icarus was ten thousand times weaker than Earth’s: Sherrard and his space-pod weighed less than an ounce here, and once he had set himself in motion he floated forward with an effortless, dreamlike ease.

Yet that very effortlessness had its dangers. He had traveled several hundred yards, and was rapidly overhauling the sinking star of the Prometheus, when overconfidence betrayed him.

From SUMMERTIME ON ICARUS by Arthur C. Clarke (1960)


This is from Launching and Alightment Systems for Aero-Space Vehicles by the Wright Air Development Division. In the middle part of the report, they figure that it will be a big problem for two spacecraft to rendezvous safely. So they looked into all sort of possibilites.

Waldoes And Drones

For maximum protection of the astronauts, it is best to help them avoid leaving the spacecraft at all. They can stay in the relative safety of the habitat module while using waldo robot arms or free-flying drone pods to get the job done.

Waldoes are also used for berthing a spacecraft (not docking, berthing).


Mobile Servicing System (MSS)

The MSS is composed of three components — the Space Station Remote Manipulator System (SSRMS), known as Canadarm2 (successor to the original Canadarm), the Mobile Remote Servicer Base System (MBS) and the Special Purpose Dexterous Manipulator (SPDM, also known as Dextre or Canada hand).

Canadarm2 is usually attached to the MBS, which moves along a rail. However, Canadarm2 can detach and literally walk on the surface of the station to where it is needed, moving end-over-end like a giant metal inch worm. Either end can plug into special sockets ("power data grapple fixtures") built at strategic spots on the surface of the station. The only draw-back is that Canadarm2 cannot carry any equipment while in inch-worm mode, hence the MBS.

The main limitation is that each "step" must end at a socket, but this is due to power and control signal issues. A more advanced version might be self contained enough to not require sockets, just hand-holds or other protrusions that it could grab.

Canadarm 2 is quite large, 17.6 meters (57.7 feet) long when fully extended. It can move payloads with a mass up to 116 metric tons.


This is From Nuclear Shuttle Systems Definition Study Phase III Final Report Volume II Concept and Feasibility Analysis Part A - System Evaluation and Capability. Thanks to Erin Schmidt for bringing this report to my attention.


DARPA’s Robotic Servicing of Geosynchronous Satellites (RSGS) program is to develop technologies that would enable cooperative inspection and servicing satellites in GEO.

1964 Lockheed unmanned SCHMOO drone: "Space Cargo Handler and Manipulator for Orbital Operations"

G.E. Remote Manipulator Spacecraft (1968)

Space Tug

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Space Tug: Boeing

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Modules and Kits

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Sample Tugs

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Space Tug: Dornier

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Space Tug: Grumman

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Space Tug: Johnson Space Center

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Space Tug: Lockheed

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Space Tug: NASA

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Modules and Kits

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Sample Tugs

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Space Tug: Parkinson

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Space Tug: Tinsley

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Space Tug: ULA

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Space Tug: William Black

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Space Tug: Other

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Skeletons And Spacesuits

I noticed a couple of pulp covers with skeletons in spacesuits. So I looked on Google image search. I had no idea it was such a wide-spread meme.

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