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.

We're looking at Earth science, observing our planet. Also space science, looking at the ozone in the atmosphere around our Earth. Also looking at life science. And on a human level, using ourselves as test subjects.

Gravity pulls our bodily fluids down, like water in a glass goes to the bottom part of a glass. In space, the water doesn't stay in the bottom of the glass. It distributes itself evenly over time throughout the entire volume of the glass.

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.

Life continues in lots of places, and life is a magical thing.

Everyone that I've talked to who's been to space has thoroughly enjoyed the experience, and what you often hear them say is: It was great, but we just had to come home.

Life science research can be done on multiple platforms. Since we have a very small number of people flying into space, the more people you have, the better.