The most important thing about an astronaut is you have to take for a given a person's done pretty well in school, has the intelligence and all of that to learn new systems and new things. But after that, the most important thing I think is being able to get along with others. Flexibility and teamwork, those issues because as we fly longer and longer in space, those are really important factors, even on short shuttle missions, those are important factors, to put a crew together that can work together effectively as a team, that can get along.

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.

Rockets have remained fundamentally unchanged, except for a few exceptions for the last almost 50 years. So, for there to be a fundamental shift in rocketry and getting into space, there almost has to be a breakthrough in propulsion. Either in how to bring the price down, or how to more efficiently get people up into space and the key barrier is the expense of a rocket.

I hope that China will continue with space exploration. It would be logical to have international co-operation. I hope that it will come about and that I can be involved in it.

We have self-assessment tools, computer-based tools to see how we are performing mentally in outer space and there's some also very interesting technology and work that's being funded by NRSBI to look at facial recognition to look at your patterns to see if you're experiencing stress or fatigue. It's a kind of thing that I think will gain acceptance with gradually. But it probably has more to immediate application in things like homeland security, and looking at facial recognition of people going through airports and things like that to see who's under stress.

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.

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.