On March 27, 2015, Captain Scott Kelly clambered aboard the Soyuz spacecraft and blasted off from the Baikonur Cosmodrome in Kazakhstan, bound for the International Space Station, 254 miles above Earth. So began his 340 days in space, the longest single spaceflight in U.S. history. His charge? To further our understanding of life in microgravity and let scientists learn as much as humanly possible about how space affects the body.
Your year in space was a deliberate first step toward mankind’s most ambitious goal yet. Why a year, and what was this mission meant to prepare for?
The idea is that someday we want to go farther away from the Earth. And when we do that, it’s going to take us longer to get there. We’re only going to have the space station for a few more years, and it’s a good opportunity to learn more about human physiology, psychology, and the systems it takes to spend more time in space. When we go to Mars someday, it’ll take 200 days to get there. You’ll spend over a year on the surface. Then it’ll take us 200 days to get back. There are just more things we need to understand before we do that.
Like the poorly understood effects of weightlessness?
The thing about microgravity is if you’re going to do an experiment on Earth, you can only vary certain things. On Earth, you can vary G-forces in a positive way, but in space, when you can remove the force of gravity, that gives you another variable that allows you to gain new insight. That’s what makes this microgravity research valuable.
Part of your charge was to become a living laboratory.
I’m not the researcher. I was the guinea pig. Among the problems of long-duration spaceflight, there’s bone loss, muscle loss, effects of radiation at a genetic level. There are effects to our immune system, the cognitive effects, the psychological effects. We’re trying to understand these issues we sometimes have with our vision. There are changes to the structures in our eyes. There’s swelling in the optic nerve and these things called choroidal folds. It’s a fleshy part on the back of your retina that seems like it’s due to the pressure in space—an upward fluid shift in our heads. There’s concern that maybe someday they could result in blind spots.
The life support equipment is something we need to nail down better and make it more reliable, more efficient. In some cases, make it work better. That’s part of this larger experiment of the space station. The more we know, the longer people spend in space, the better we’ll know how to support them.
As a test pilot, at first you felt as though a long stint on the ISS wasn’t all that appealing. But the shuttle days were gone. You were going to be a scientist, in a sense. How was that transition?
At first, it wasn’t something I was that interested in. I was a pilot and a test pilot, and to make a long story short, I got roped into it a little bit. It was much different than a shuttle launch. [For this mission] I think it’s more important to have someone who is a good operator of experiments than it is to have someone who might be a scientist themselves. You’re also the housekeeper. You’re the cook, the engineer, the mechanic, the electrician, the doctor, the dentist, the science operator.
Having one twin on the space station for a year and the other (your astronaut brother, Mark) on the ground probably served as a nice control for your human experiment. Was that something NASA planned?
It was kind of a serendipitous thing—the happy accident. I had already been assigned to the flight and I had asked about genetic research. Apparently, the government isn’t allowed to ask their employees to participate in genetic research, but because I asked the question, that opened the door. It gave NASA the opportunity to delve into this area of genetic-based research that they’ve never been involved with before.
Anything interesting so far?
My telomeres [a part of the DNA strand associated with aging] got better compared to my brother’s. The hypothesis was that they’d get worse.
Your mother was a cop, which back then was less common for a woman. How did that serve as an early blueprint for your own goals?
She had an obstacle course in our backyard. She studied a lot for the exams, the civil service exam. My dad built a wall she had to scale during this test. She [also] had to drag a dummy, which was me. I was a good dummy. She made an impression on my brother and me, and inspired us. When you see your mom do something you don’t see anyone else’s mom doing, it makes an impression. Especially when she goes from being Mom to cop, it was something that was unexpected. At the time, it was very outside the box. Eventually, it made me a better student and made me see what it took to have a goal you think you might not be able to achieve, and then work really, really hard to achieve it.