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.

We would like to carry out 100 percent, or maybe more, of our scientific program; I would like to devote some of my spare time toward extra scientific work.

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.

In the 19th Century people were looking for the Northwest Passage. Ships were lost and brave people were killed, but that doesn't mean we never went back to that part of the world again, and I consider it the same in space exploration.

Even with only two people on board, where maintenance is a large piece of our working day, we still have time to do scientific research. We have to be ready to support those Shuttle visits in a lot of different ways.

There weren't any astronauts until I was about 10. Yuri Gagarin went into space right around my 10th birthday.

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