I was an eight-year-old kid when I watched the first Apollo Moon Landing way back in 1969 and there was something about that moment that really stuck in my head. I'd always been interested in space and flying and I was building model rockets and model airplanes, but something about that moment, I can remember like it was yesterday watching the Apollo Lunar Lander approach the surface of the Moon and then later watching Neil Armstrong and Buzz Aldrin take the first steps on the Moon, and something that day started the dream for me that, hey, I want to be like those guys.

Of course, you'll have to meet the physical and psychological demands. A space walk takes a lot of energy.

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.

The thing that you worry about your first flight or any flight is some kind of a problem coming up that is going to keep you from doing it. Whether it's being hit by a car, or getting in a bad accident, or coming down with some other medical disqualification. But once the boosters light, you're going.

I'm Chinese-American, of course, and so it's very interesting to see China actually launch their own astronauts, becoming the third nation, following the United States and Russia, to do so.

Space is very unforgiving business

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.