You will soon feel sick. Awed and humbled, you unburden yourself from your safety harness. You see the Earth, home to all you’ve known and loved, hundreds of miles below. Staring at it, through the cupola of the International Space Station, a craft that is orbiting 17,500 mph, you turn and find that all of you—really, all of you—limbs, heart, lungs, hair—is floating. You wiggle your toes and all of a sudden your body is everywhere in the room. In the pit of your stomach you feel a feeling you remember from way back, decades before, screaming down a country road in your uncle’s old pickup, hitting a rolling bump and lifting off. Only now you never come back down. The feeling in the pit of your stomach never goes away. You might throw up.

You are sick because you are confused. Your eyes are telling your mind lies that your inner ear, that register of balance and momentum, cannot abide. Your mind creates a map of the craft around you, assigning a logic to its contours: this is up, that is down, here is starboard, there is port. You move, see the space move, and your mind tries in vain to feel the effects. But your inner ear requires gravity. Without it, part of your mind—the lizard part—is certain you are still. The mixed-up messages make you space-sick.

You close your eyes and focus on your breathing and find that something incredible is taking place inside your body: Everything is floating. All of you. Every part. You feel your heartbeats rippling, echoing inside and even around you. When you open your eyes, you sense that the space station is moving, vibrating, rippling with the beat of your heart. You are an air bubble suspended in liquid. Only you aren’t. It’s your body that’s gently moving—moving to your pulse, ever so slightly. The walls of the station are still. The sensation of connectedness is transcendent.

The moment does not last very long. Every day is scripted. You have almost no free time. Pre-sleep and post-sleep: Thirty minutes, maybe an hour, at the beginning and end of each day, maybe some downtime around lunch. You run tests, mostly. On weekends, you get a day-and-a-half off, but even then much of the time is spent on housekeeping—cleaning air filters, replacing pipes. Every day you work out for two hours, mandatory, to keep your muscles from atrophying.

The exercise equipment is right above (or below) the cupola, the window at the observatory of the space station. You lie on the floor (or ceiling) and stare at the window and watch Australia float by.

After a few days you feel better. Your crewmates tell you that you’ve got your spacelegs. You recognize that you aren’t in space because you deserve to be there—you’re just lucky. You’re having this experience for the rest of mankind. So you begin to experiment. Not the scheduled experiments. You test your body. You play.

First you spin. Spinning is big. You curl into a ball and one of your crewmates spins you up. Keep your eyes closed and you’ll be OK. But you have to be careful with the spinning. People get sick.

You spin other things: spoons, wrenches; M&M’s, water globs, globs of soup, globs of all kinds. Foods are big. You toss the M&M’s across the ISS for your crewmates to catch in their mouths. You float things as far as they will go. Not heavy things, but of course there’s the game you all play: How far can you float without banging into things? The Russians are particularly good at this.

You play with water a lot. Water is amazing. You can make a ball of it, and it becomes a big old glob just floating around. Then, if you smack it, it splatters into small droplets. If you gather up a big ball and stick your eye in front, the floating sphere of water magnifies it. Your eye looks huge. It’s funny.

You study acoustics, testing sonic vibrations on the surface tension of water. You modify a spare hose and play it like a didgeridoo. You play surprisingly well, and the surreal baritone buzz causes the globs of H2O to quake and rumble until—incredibly—the sine waves of water become so pitched and violent that tiny globules shoot off in all directions, like miniature galaxies after the Big Bang.

The craft is cramped, but you soon realize you have this entire volume of space you didn’t before. You find a corner, tucked away in what looks like a ceiling, and you sit there and listen to music and write. Sometimes you hang down like Spider-Man, feet on the ceiling. Up is down and down is up and ceilings are floors. For years after your mission—maybe for the rest of your life—when you walk into a room, you look up. In space, you get used to seeing and using all the space in a room.

You make a sock into a ball. Two white sweat socks, rolled up: baseball, soccer. A crewmember brought a little football. The first time you throw it, you throw like you’re on the ground—your brain subconsciously knows you have to aim higher. You have to retrain your brain, nullify the unconscious element that tells your arm to throw 10 feet above someone’s head to account for gravity. After you do, you have pinpoint accuracy.

You play games with the ground—the people on Earth. You tweet a photograph you take of the Earth from your celestial perch and ask people to guess what part of the planet it is. The Internet has changed the job. You’re up there—you have an obligation to share what you’re experiencing.

You never tire of the view. You dance, you spin, you play with your food, you read on the ceiling. It’s pretty obvious to you now that you, your crewmates, and everything you see is formed from the same dust, and that dust comes from stars. It’s cheesy, you know, but it’s also true. You understand, deeply, the word awesome. When you look at the window everything you see is awesome.

You come back changed. You are more mindful, more willing to believe in the mystical. You have regained that sense of wonder lost in childhood. You think very deeply about the future, and what it might be like on a starship that’s charting a course farther into the cosmos than we’ve ever ventured. What would it be like, aboard this centuries-long journey? And what might we learn about our shortcomings back here on Earth?

This story is the result of three long interviews with astronauts Ronald J. Garan, Michael Massimino, and Mae Jemison, as well as video and previously published interviews with astronauts Nicole Stott, Donald Pettit, Chris Hadfield, Michael Collins, Jim Lovell, and Edgar Mitchell. Much of the text—the most poetic moments, especially—comes directly from the astronauts. Special thanks to NASA Johnson Space Center for helping arrange interviews and research material. An edited version of this story originally appeared in Kill Screen magazine.

Cupola image via NASA’s Marshall Space Flight Center

Star-trail image via NASA APPEL