IF YOU STUMBLED onto Building 993 at Houston’s Ellington Field airport, you would have to stop and wonder about the things inside. The sign on the front is as evocative as the one that says “Ministry of Silly Walks” in the old Monty Python sketch of the same name. This sign says REDUCED GRAVITY OFFICE. I know what is in there, but even so, I have to stand for a moment and indulge my imagination, through which coffee pots are floating and secretaries drift here and there like paper airplanes. Or better still, an organization devoted to the taking of absolutely nothing seriously.
The actual Reduced Gravity Office oversees a NASA program whereby college and high school students compete for the chance, twice each year, to carry out zero-gravity research projects during a parabolic flight on a jet stripped of most of its seats. I’m signed on as a journalist observing a college team that is studying zero- and reduced-gravity welding. In my press materials, there’s a photograph of a McDonnell Douglas C-9 military transport jet powering through the upward climb of a parabolic arc. It is flying at an absurd angle, the way a child moves a toy plane through the air.
IT WAS A team of brothers, Luftwaffe aerospace medicine pioneers Fritz and Heinz Haber, who, in 1950, dreamed up the technique known today as parabolic flight. The Habers theorized that if a pilot flies the same kind of parabolic arc as a short-range rocket (or a baseball pop fly), then the passengers, for anywhere from 20 to 35 seconds at the top and the downward segments of the arc, will experience weightlessness. If the pilot then pulls out of the downward dive and heads back up and repeats the process, over and over until his fuel runs low, science will have an accumulation of several minutes of weightlessness to work with—at a fraction of the cost of building and launching rockets.
This was the moment when aerospace professionals were first contemplating sending men to the moon, and they were gripped with almost universal foreboding at the prospect of cutting loose from gravity’s hold. What if man’s organs depended on gravity to function? What if the pumping of the heart failed to push his blood through his veins, and instead merely churned it in place? What if his eyeballs changed shape and compromised his visual acuity? If he cut himself, would his blood still coagulate? They worried about pneumonia, heart failure, debilitating muscle cramps. Some fretted that without gravity, signals from floating inner-ear bones and cues to the body’s position would be absent or contradictory—and that this might cause perturbations that would, to quote Heinz Haber and his colleague Otto Gauer, “ultimately produce a very severe sensation of succumbence associated with an absolute incapacity to act.” Succumbence?
Monkeys, of course, manned the group’s first experimental rocket flights, but a pilot named Joe Kittinger was the first human to test the Habers’ theory. “You can’t get any real fun things unless you volunteer,” Kittinger said later in an oral history that’s on file at the New Mexico Museum of Space History. Kittinger would take a plane up at a 45-degree angle, and then arc it over and plunge back down, all the while watching a golf ball suspended on a string from the cockpit ceiling. “That was our instrumentation!” Kittinger told me. When the plane achieved zero gravity, the golf ball started floating. So did Kittinger, of course, but he was strapped in his seat.
As soon as it became clear that a few seconds of weightlessness was more entertaining than it was troublesome, the aerospace medicine crowd began to apply its boundless energy to the scenario of longer-duration missions. Would an astronaut on a three- or four-day orbit of Earth or a trip to the moon be able to eat, or did he need gravity to help the food along. How would he drink water?
Kittinger has a name for those researchers: weenies. “There were scientific papers put out all over the place by the experts that said that [zero gravity] was going to be the limit of putting man in space,” he says in his oral history. “And I just sat there and laughed my butt off, because I loved it! I thoroughly enjoyed it!”
YOU NEVER THINK about the weight of your organs inside you. On Earth, 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. Your 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 today 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. One of those fools is me. (The other is Joyce, from the education department at NASA Headquarters in Washington, D.C. She helps run the student flights program, but had never been on one of the flights before.) Imagine the scene: 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 post-party. When I got back to my room and reviewed my notes, I found that I’d written nothing of substance. I wasn’t so much taking notes as testing my Fisher Space Pen. My notes say: “WOO” and “yippee.”
I once heard a NASA astronaut say, in response to a schoolchild’s question, 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 mostly empty C-9, for 22 seconds at a go, you are floating in air without effort, without help, without resistance. Gravity has given you a hall pass.
Our appearances change, too. One NASA researcher calls this the Space Beauty Treatment. Without gravity, your hair has more body. Your breasts don’t sag. More of your body fluid migrates to your head and plumps your crow’s feet. (Then again, I have heard this same phenomenon called puffy face syndrome.)
“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 short period when the plane is accelerating and the force of gravity doubles, 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 30 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 Apollo 11 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.”
There is some annoyance going on today on our C-9 mission. 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 a dive.
Nothing works as it’s supposed to in zero gravity. “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 in 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.
Human machinery malfunctions too. Motion sickness is a routine hazard of weightlessness, and as I float about the plane I can see one member of the space welding team hunched over in a seat, a white bag hovering near his face. With all that any space mission has riding on the health of its crew members, you’d think science would have licked motion sickness by now. So far, there’s no cure.
At least one device in the C-9 is working as designed, though. On the ceiling is a red numerical display of the type you see at deli counters, telling patrons which number is being served. This one is counting our parabolas—27 so far. Three more and it’s over. We were told not to “go Superman-ing around the cabin,” but I have to break the rules. As gravity fades out on the 28th parabola, I pull up my legs, crouch on a 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.
Excerpted from Packing for Mars: The Curious Science of Life in the Void by Mary Roach. ©2010 by Mary Roach. Used with permission of the publisher, W.W. Norton & Co., Inc. All rights reserved.