We're going to be focusing our science on things that will take us farther and longer into space. For many of those experiments, the crew members are human guinea pigs, which is fine; that's part of my job. I don't mind being a human guinea pig.

Every day, we get a little bit closer to the kind of expertise and the kind of experience we're going to need to go there. I'd love to be the guy walking on Mars.

It took me a long time to get selected as an astronaut. In fact, I applied for 20 years before I was selected.

I think it's going to be a very important, unique data set in terms of measuring the behavior of your lower body in space and trying to figure out what we can do to preserve bone and muscle density.

We're going to be focusing our science on things that will take us farther and longer into space. For many of those experiments, the crew members are human guinea pigs, which is fine; that's part of my job. I don't mind being a human guinea pig.

A civilization that only looks inward will stagnate. We have to keep looking outward; we have to keep finding new avenues for human endeavor and human expression.

I never made a career decision based solely on my desire to be an astronaut. I attended the Naval Academy because I wanted to be a Navy pilot. I majored in math because math had always come pretty easily to me and I liked it.