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.

After assembly complete, when we have a larger crew on orbit, a more complex vehicle, more laboratories and more robot arms, maybe we'll have room for specialists. But right now we don't.

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.

Researchers can measure what kind of angles your legs take up during the day when they're just trailing around behind you in weightless conditions, and what kind of impacts you feel during your exercise. They're going to compare that with what we do on the ground.

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.

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.

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.