The microgravity or the very, very low amount of gravity that we have up in space forces some changes in different processes. It forces changes in us as human beings.

We've had such thorough training, we've had an excellent team on the ground. With the minor glitches that have occurred, we've been able to take care of them. And the teams on the ground are getting tons of incredible data.

There's a lot of different things that we do during life that could personally harm us and I choose not to stop doing those things.

The Navy's paid for you to go through school, and then they need doctors to go out and take care of people who are in various different parts of the world. I decided to pay back my time first as an undersea medical officer. I was stationed in Scotland.

If you're trying to get someone who's sick with a fever off of a submarine and it's cold and raining outside, the only way in and out of a submarine, generally, is through a fairly narrow hatch.

Whenever I do get to look out, it is glorious. Even the stars have a special brightness.

There are some very significant changes in the way the fluids are distributed in our body, the way our heart functions initially, and as well as our bone and muscle.