Packing for Mars: The Curious Science of Life in the Void

by Mary Roach

  He doesn’t know. He’s on the ground crew and does not get to fly. He gives me a forced smile. “It’s okay.” And then, remembering words that someone has told him to say: “It’s an honor just to be here.”

  By midday, the welding unit is back on board, affixed directly to the floor of the plane. Space Weld Team is go for launch.

  YOU NEVER THINK about the weight of your organs inside you. Your heart is a half-pound clapper hanging off the end of your aorta. Your arms burden your shoulders like buckets on a yoke. The colon uses the uterus as a beanbag chair. Even the weight of your hair imparts a sensation on your scalp. In weightlessness, all this disappears. You organs float inside your torso.* The result is a subtle physical euphoria, an indescribable sense of being freed from something you did not realize was there.

  If you go to the NASA Microgravity University Web page, you will see photo after photo of students concentrating intently on their projects and, in the background of many of these shots, a pair of grinning fools floating into each other like shirts in a dryer. That’s me and Joyce. Joyce is from the education department at NASA headquarters in Washington. She helps run the student flights program but had never been on one of the flights. I should really be down on the floor with my team, taking notes on how it’s going. I can’t do this, however, because my notebook is floating in front of my face with the pages all fanned out, and I need to stare at it for a while longer. It hovers, not rising and not falling, in the manner of a party balloon a few days postparty. (When I get back to my room to review my notes, I find that I’ve written nothing of substance. I wasn’t so much taking notes as testing my Fisher Space Pen. My notes say: “WOO” and “yippee.”)

  Last night on NASA TV an astronaut, in response to a schoolchild’s question, said that being in zero gravity was like floating in water. Not exactly. In water, you sense the liquid’s help—buoying you and supporting your weight. When you move, you feel it push back on you. You are floating, but a heaviness remains. Here on the C-9, for twenty-two seconds at a go, you are floating in air without effort, without help, without resistance. Gravity has given you a hall pass.

  The thing weighing us down is Del Rosso. He has told us to hold on to a strap with one hand. This means that every time I’m floating, I reach the limits of my tether and swing around to the left. This causes me to enter the air space over the Kansas University team’s electromagnetic docking rig. To retreat, I have to extend my leg down and push off the frame of it. “Don’t kick their experiment!” barks Del Rosso. Like I meant to. I hate your stupid electromagnetic docking thing, take that! It’s just that this floating business takes getting used to. You can ask Lee Morin. Mission Specialist Morin told me it takes about a week to feel comfortable floating. “Then it seems like the natural thing. To float like an angel. I don’t know whether it’s like you’re, you know, back in the womb or something, but it’s like the natural way. And it seems very odd to think about walking with shoes.”

  “Feet down!” yells a blue flight suit. This is our cue to bring our legs back underneath us, because gravity is coming back. It comes on gently—you’re not dropped from the ceiling—but still, you don’t want to come down on your head. Some of us lie on our backs during the double gravity portion, as we’ve heard we’re less likely to become nauseated that way.

  Gravity disappears again, and we rise up off the floor like spooks from a grave. It’s like the Rapture in here every thirty seconds. Weightlessness is like heroin, or how I imagine heroin must be. You try it once, and when it’s over, all you can think about is how much you want to do it again. But apparently the thrill wears off. “At first,” wrote astronaut Michael Collins in a book for young adults, “just floating around is great fun, but then after a while it becomes annoying, and you want to stay in one place…. My hands kept floating up in front of me, and I wished I had pockets or somewhere to put them.” Astronaut Andy Thomas told me how irritating it was to never be able to set something down. “Everything has to have a bit of Velcro on it. You’re forever losing things. I brought one nail file with me on Mir, so I was very careful with it. About a month before the end of the mission, it popped out of my hand. I turned to grab it, and it was just gone. It went down with Mir. Once we lost a whole Sharps container. Big thing. Gone. We never saw it again.”

  There is some annoyance going on today. One team’s computer keeps shutting down. It’s one of those rugged laptops that protect themselves by shutting down when they detect a sudden spike in acceleration. On Earth, this means it has been dropped. Up here, it means the pilot is pulling out of the dive.

  Nothing works as it’s supposed to in zero gravity, or zero G, as it’s also known. “Even something as simple as a fuse,” astronaut Chris Hadfield told me, mistaking me for someone who knows how a fuse works. Now I know: Fuses have a metal strip that melts in response to a surplus of current. The molten bit drips away, leaving a gap that interrupts the power flow. Without gravity, the droplet doesn’t drip, so the power continues to flow until the metal boils, by which time the equipment has fried. Zero gravity is part of the reason NASA price tags seem so extravagant. For every new piece of equipment that goes up on a mission—every pump, fan, throttle, widget—a prototype must be flown on the C-9 to be sure it works in weightlessness.

  Overheating equipment is a common theme in zero G. Anything that generates heat tends to overheat, because there are no convection currents in the air. Normally, hot air rises—because it’s thinner and lighter; the livelier molecules are all bouncing off each other and spreading out more than they do in cooler air. When hot air rises, cooler air flows in to fill the vacuum left behind. Without gravity, nothing is any lighter than anything else. It’s all weightless. The heated air just sits where it is, getting hotter and hotter and eventually causing damage to the equipment.

  Human machinery tends to overheat for the same reason. Without fans, all the heat that exercising astronauts generate would hang around their body in a tropical miasma. As would exhaled breath. Crew members who hang their sleeping sacks in poorly ventilated spots get carbon dioxide headaches.

  In the case of the Space Weld Team, it is the human machinery that’s most notably out of commission. It’s not something you can fix with a fan.

  THROWING UP AND DOWN

  The Astronaut’s Secret Misery

  On the ceiling of the C-9 is a red numerical display of the type you see at deli counters, telling patrons which number is being served. This one is counting parabolas, twenty-seven so far. Three more and it’s over. We were told not to “go Supermanning around the cabin,” but I have to break the rules. As gravity fades out on the twenty-eighth parabola, I pull up my legs, crouch on the windowpane, and then gently uncoil, launching myself across the cabin of the plane. It’s like pushing off from the wall of a swimming pool, but the pool is empty and it’s air you’re gliding through. It’s probably the coolest moment of my entire life. But not of Pat Zerkel’s life. The Missouri space welder has been belted down in the front row of seats. Though weightless, he appears heavily burdened. A white bag hovers near his face. It is held open with both hands, like a hat carried through a crowd for tips.

  “OOOooulllrr-aaghchkkk, khkkk.” Pat has been ill since the fourth parabola. At parabola number 7, the flight surgeon came over to hold him steady during the weightlessness, hoping it would help. (And to keep him, as he told me later, from “floating away helpless and vomiting everywhere.”) At parabola number 12, men in blue flight suits gave Pat a shot and helped him to the back of the plane, where he would remain for the rest of the flight.

  The special evil of motion sickness, the genius of its cruelty, is that, generally speaking, it hits you when you’re up. A sunset sail on the San Francisco Bay, a child’s first roller-coaster ride, a rookie astronaut’s first trip to space.* There is no faster route from joy to misery, from yee-ha to oooulllrr-aaghchkkk.

  In space, motion sickness is more than an unpleasant embarrassment. An incapacitated crew member makes
for the most costly sick day in the world. An entire Soviet mission, Soyuz 10, was aborted due to motion sickness. You’d think science would have it licked by now. It’s not for want of trying.

  TO FIGURE OUT how best to prevent motion sickness, you first need to figure out how best to bring it on. Aerospace research has excelled at the latter, if not the former, and perhaps nowhere more triumphantly than at the U.S. Naval Aerospace Medical Institute in Pensacola, Florida: the birthplace of the human disorientation device. In a 1962 NASA-funded study, twenty cadets agreed to be harnessed to a chair mounted on its side on a horizontal pole. Thus affixed, the men were rotated, rotisserie style, at up to thirty revolutions per minute. As a reference point, a chicken on a motorized spit typically turns at five revolutions per minute. Only eight of the twenty made it to the end of the experiment.

  The motion sickness inducer of choice these days is the rotating chair.* Here the rider sits upright upon the seat, as if preparing to take dictation. A small motor causes the chair to spin on its base, conferring, at first glance, a joyful air to the proceedings, as though the subject had set herself awhirl—the tipsy stenographer at the office Christmas party. At the experimenter’s command, the subjects, eyes closed, tilt their heads left and then right while spinning. I took a brief turn in the rotating chair that resides in the lab of space motion sickness researcher Pat Cowings, at NASA Ames. At the first head tilt, something lurched inside. “I can make a rock sick,” said Cowings, and I believe her.

  What has aeromedical science learned from the combined tortures of motion sickness research? For starters, we now know what causes it: sensory conflict. Your eyes and your vestibular system can’t get their stories straight. Say you are a passenger belowdecks on a heaving ship. Since you are moving along with the walls and floor, your eyes report to your brain that you are sitting still in the room. But your inner ear tells a conflicting story. As the ship moves you up and down and around, your otoliths—tiny calcium pebbles that rest atop hairs that line the vestibule of the inner ear—register these movements. If the ship dips down into a trough, for instance, the otoliths rise; when the ship crests, they press down. Because the room is moving with you, your eyes detect neither. The brain gets confused and, for reasons not well understood, responds by nauseating you. Soon you are heaving too. (This is why it helps to stay up on deck, where your eyes can register the boat’s motion relative to the horizon.)

  Zero gravity presents a uniquely perplexing sensory conflict. On Earth, when you’re upright, gravity brings your otoliths to rest on the hair cells along the bottom of the inner ear. When you lie down on your side, they come to rest on the hairs on that side. During weightlessness, the otoliths, in both situations, just float around in the middle. Now if you suddenly turn your head, they are free to ricochet back and forth off the walls. “So your inner ear says you just laid down and stood up and laid down and stood up,” says Cowings. Until your brain learns to reinterpret the signals, the contradiction can be sick-making.

  Given the culpability of the human otolith, it is not surprising to learn that sudden head movements are extremely, to use the lingo of motion sickness experts, “provocative.” If you look at back issues of Aerospace Medicine, you can find pictures of grim-looking World War II troops with their heads wedged between padded vertical slats on the walls of troop transport planes: someone’s attempt to stem the vomitous tide. (The smell of other people’s emissions in close quarters is also highly “provocative.” Cowings likes the term “inspirational.”) Airsickness and seasickness were serious enough problems during the war that the government, in 1944, convened an entire United States Subcommittee on Motion Sickness. (Then again, it has also convened a U.S. Subcommittee on Poultry Nutrition and one on sedimentation.) Charles Oman, resident motion sickness expert at the National Space Biomedical Research Institute, confirmed the perils of wanton head-swiveling by mounting accelerometers on the backs of astronauts’ headwear. The ones who, just by nature, tend to jerk their heads around a lot are the ones most likely to suffer from motion sickness during a mission. What’s true in space is true in a car on a winding road: No matter how much the driver behind looks like the GEICO caveman, don’t whip your head around to look. According to work done by prolific 1960s motion sickness researcher Ashton Graybiel, even one head movement in highly susceptible people produces a measurable increase in their sweat level—an indication that nausea is just around the bend.*

  “We actually proposed making a beeping beanie,” Oman said. If astronauts moved their head too fast or too much, they’d hear a beep letting them know. Oman did not record the astronauts’ responses to the beeping beanie proposal, but I’m guessing they were fairly, as they say, “provocative,” for no astronautical beanie-wearing ensued. Oman did manage to get astronauts on one mission to agree to try out padded collars designed to discourage extraneous head movements, which they promptly removed. “It was perceived as an irritant,” Oman said ruefully.

  Astronauts have to deal with the mother of all sensory conflicts: the visual reorientation illusion. This is where up, without warning, becomes down. “You were working on a task…and apparently reorienting your ‘down’ without thinking about it, and then turning away and finding that the whole room was completely cattywampus to what you thought it was,” recalls a Spacelab astronaut quoted in one of Oman’s papers. (This may have been Pat Zerkel’s problem; he told me he’d had “the distinct feeling of losing any sense of up or down.”) It happens most readily in spaces with no obvious visual clues as to which is the floor and which the ceiling or wall. The Spacelab tunnel was notorious. One astronaut found traveling through it so reliably nauseating that, he told Oman, he’d sometimes pay a visit simply to make himself “get better by vomiting.” Even just a glimpse of a fellow astronaut oriented differently from oneself could bring it on. “Several Spacelab crew described sudden vomiting episodes after seeing a nearby crew member floating upside down.”* Nothing personal.

  Experts like Oman keep changing their minds about whether drugs are a good idea. In space, as at sea, recovery is a process of adaptation; if you’re under the covers in the fetal position, you’re not exposing your vestibular system to the new reality. Overdoing it, on the other hand, can mean crossing the threshold and making yourself sick. Drugs help keep astronauts out of bed, moving and going about their work. But they also confer a false sense of immunity, encouraging one to overdo it. Motion sickness drugs don’t make you immune; they simply raise the threshold for sickness.

  For anyone taking a short trip, across the Channel or on the C-9, drugs are the answer. NASA gave us Scop-Dex (the dextroamphetamine counteracting the sedating effects of the scopolamine). Even then, most flights have at least one or two “kills,” as the blue flight suits call the stricken. Pat looked queasy before the parabolas even began. It’s possible he’s someone who developed a conditioned response to the sight of a vehicle—in his case, a plane—that once upon a time made him horrifically ill. People who say they “get sick just looking at a boat” are not always exaggerating. (Relaxation and counterconditioning techniques can help in these cases.) People also develop conditioned responses to the smell of vomit. “This is why motion sickness can seem contagious,” says Oman.

  One thing the Pensacola research proved is that it helps to focus on something other than how you are feeling. The eight who finished rotisserating on the human disorientation device were those who had been given “constant mental arithmetic” tasks or timed button-pushing sequences to complete. Mental as opposed to written, because the last thing you want to be doing when you’re fighting off motion sickness is reading. In particular, avoid reading papers such as “Analysis of Vomitus and Contents of Gastrointestinal Tract.”

  RUSTY SCHWEICKART DID everything wrong. Schweickart was an astronaut on Apollo 9, charged with testing the life-support backpack that the Apollo 11 crew would wear on their history-making stroll on the moon. Schweickart was to put it on, power it up, and head into the depressurized L
unar Module. Because he’d been sick during parabolic-training flights, he’d been exceedingly cautious the three days leading up to the spacewalk. “My whole modus operandi…” he said in his NASA oral history, “was to keep my head as still as possible and not to move around a lot.” There’s the first problem: He delayed his adaptation. On day three, Schweickart had to put on his EVA suit. This is, as he describes it, a “real contortionist challenge” with a lot of ducking down and doubling over. Problem 2: head movements. “Suddenly I had to barf,…and I mean, that’s not a good feeling. But of course you feel better after you barf.” Encouraged, he continued his preparations, moving over to the Lunar Module. Problem 3: the dreaded visual reorientation illusion. “You’re used to being up, and when you go over there, it’s down.” When he got there, he had to wait for his crewmate to catch up to where he was on the checklist of tasks. “I’ve basically got nothing to do.” Problem 4. “When your mind is suddenly—[its] priorities are gone, then…malaise gets the top priority in your brain. All of a sudden, I had to barf again.”

  With space motion sickness, the impulse to vomit can hit with unusual suddenness. One of Oman’s Spacelab interviewees recalls sitting with a colleague who was eating an apple. “Right in the middle of it, he said, ‘Aw gee!’ threw the apple in the air, and vomited just like that.” Launch-pad workers stuff extra vomit bags in rookies’ pockets before liftoff, but even then, unfettered hurls are common.* NASA etiquette is to clean it up yourself. As one of Oman’s Spacelab interviewees says, “Nobody else is going to do that work for you—and you sure don’t want anybody to.” Though you couldn’t accuse Schweickart’s fellow astronauts of a lack of compassion. Herewith, the most touching moment in the 1,200-page mission transcript from Apollo 9.