I loved flying as much as I thought I would and continue to fly aircraft.

I had done everything I could do as an astronaut, and we have a long line of inexperienced astronauts waiting for their first missions, and so my role really should be to step aside and help them prepare for their missions, rather than to try to get another mission.

Space is very unforgiving business

As commander I was responsible for the overall success of the mission, and so I had to know at least a little bit about everything.

Exercise is very important, first of all if you think about it, especially in a long flight like a six month space flight and on the ISS. If you didn't exercise and used the analogy on earth, it would be like laying in bed. So, just imagine laying in bed for several months, and even just trying to get up and walk, you probably wouldn't be able to. But if you got up and you exercised two hours a day, you'd probably be okay, and that's the same in space.

This was the first time we had two ex-Soviet Cosmonauts in Houston. A lot of us, including me, viewed it with some skepticism, because I grew up during the Cold War, so I had been hit with all this propaganda all along that their stuff wasn't that good, it wasn't that safe and we were so much better. What I found out later was that their space stuff was very good and good enough that I was certainly comfortable flying on their equipment. So, it was kind of a revelation of sorts as the years went by and I think it underscores the importance right now of international cooperation.

One of the things, and the most exciting, actually definitely the most exciting thing is, having children. You know, I didn't have children before. I had been married only a year before my space station mission, so having three-year-olds is a whole new experience and that's the new adventure. It may sound funny because people have kids every day, but having your own kids, having my own kids, was as fundamentally, or maybe even more fundamentally life changing then even flying in space.