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.

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.

Since the Columbia accident, the Russian space agency, or the Russian space program, has been literally carrying the load bringing us all the supplies we need on the Progress vehicle, smaller amounts on the Soyuz vehicles.

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.

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.

It so happened that my goals kind of matched my career progression toward becoming an astronaut.

The Space Shuttle will stop directly below the Space Station and Sergei and I will be looking out two different windows looking straight down at the Space Shuttle.