Scott Kelly served on the International Space Station for 340 days, partly as an experiment to see how the human body held up in long term weightlessness. Not well, it turns out. Kelly writes about his experience on finally returning to Earth.
I struggle to get up. Find the edge of the bed. Feet down. Sit up. Stand up. At every stage I feel like I’m fighting through quicksand. When I’m finally vertical, the pain in my legs is awful, and on top of that pain I feel a sensation that’s even more alarming: it feels as though all the blood in my body is rushing to my legs, like the sensation of the blood rushing to your head when you do a handstand, but in reverse.
I can feel the tissue in my legs swelling. I shuffle my way to the bath room, moving my weight from one foot to the other with deliberate effort. Left. Right. Left. Right. I make it to the bathroom, flip on the light, and look down at my legs. They are swollen and alien stumps, not legs at all. “Oh shit,” I say. “Amiko, come look at this.” She kneels down and squeezes one ankle, and it squishes like a water balloon. She looks up at me with worried eyes. “I can’t even feel your ankle bones,” she says.
“My skin is burning, too,” I tell her. Amiko frantically examines me. I have a strange rash all over my back, the backs of my legs, the back of my head and neck – everywhere I was in contact with the bed. I can feel her cool hands moving over my inflamed skin. “It looks like an allergic rash,” she says. “Like hives.”
I’m rather appalled that this experiment was done at all — we’ve known about the deleterious effects of shorter periods of weightlessness for a long time, so it’s bizarre that they pushed for longer and longer exposures. Were they hoping everything would just get better, that the human body would adjust to living in space? Because if they did, they’d have made returning home even more traumatic.
Face it, if we’re going to have people working in space for months or years, the hardware is going to have to provide some kind of substitute for gravity — great big spinning wheels, ala 2001, or built-in central centrifuges. I would hope that our space agencies would stop wrecking human bodies in pointless exercises in endurance.
I can think of more productive experiments. How much gravity is enough? Do we need a full 1G to be healthy, or would, for instance, .38G, as found on Mars, be enough? Of course, to do that kind of experiment they would need to build one of those rotating space stations, so we’re talking big money and a reset of the ISS.
We’re also ignoring the effects of prolonged radiation exposure. It’s not just the weightlessness. I have the feeling that there are a lot of ghoulish doctors working for NASA who are going to be ticking off symptoms and writing papers on the deterioration of human bodies in space,
which will be ignored by the administrators and politicians who will make speeches about the heroic sacrifices our brave astronauts are making.
An alternative strategy: let’s train tardigrades to crew space ships, if we must have biological entities aboard.