Have Space Suit—Will Travel

by Robert A. Heinlein

  I certainly did. Dad and I compromised by toting the crate and packing out to the barn. 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 Eskimo 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.

  They left and presently we went to bed, leaving the suit in the living room.

  About midnight I catfooted down and tried it on again.

  The next morning I moved it out to my shop before I went to work. Mr. Charton was diplomatic; he just said he’d like to see my space suit when I had time. Everybody knew about it—my picture was on the front page of the Clarion along with the Pikes Peak Hill Climb and the holiday fatalities. The story had been played for laughs, but I didn’t mind. I had never really believed I would win—and I had an honest-to-goodness space suit, which was more than my classmates had.

  That afternoon Dad brought me a special delivery letter from Skyway Soap. It enclosed a property title to one suit, pressure, serial number so-and-so, ex-USAF. The letter started with congratulations and thanks but the last paragraphs meant something:

  Skyway Soap realizes that your prize may not be of immediate use to you. Therefore, as mentioned in paragraph 4(a) of the rules, Skyway offers to redeem it for a cash premium of five hundred dollars ($500.00). To avail yourself of this privilege you should return the pressure suit via express collect to Goodyear Corporation (Special Appliances Division, attn: Salvage), Akron, Ohio, on or before the 15th of September.

  Skyway Soap hopes that you have enjoyed our Grand Contest as much as we have enjoyed having you and hopes that you will retain your prize long enough to appear with it on your local television station in a special Skyway Jubilee program. A fee of fifty dollars ($50.00) will be paid for this appearance. Your station manager will be in touch with you. We hope that you will be our guest.

  All good wishes from Skyway, the Soap as Pure as the Sky Itself.

  I handed it to Dad. He read it and handed it back. I said, “I suppose I should.”

  He said, “I see no harm. Television leaves no external scars.”

  “Oh, that. Sure, it’s easy money. But I meant I really ought to sell the suit back to them.” I should have felt happy since I needed money, while I needed a space suit the way a pig needs a pipe organ. But I didn’t, even though I had never had five hundred dollars in my life.

  “Son, any statement that starts ‘I really ought to—’ is suspect. It means you haven’t analyzed your motives.”

  “But five hundred dollars is tuition for a semester, almost.”

  “Which has nothing to do with the case. Find out what you want to do, then do it. Never talk yourself into doing something you don’t want. Think it over.” He said good-bye and left.

  I decided it was foolish to burn my bridges before I crossed them. The space suit was mine until the middle of September even if I did the sensible thing—by then I might be tired of it.

  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.

  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 y
ou 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 be 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 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 the 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 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 up. 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 but I hadn’t rigged it yet, so I had to 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.