My advice for an aspiring astronaut is to really follow your passion. I mean, study something that interests you, but also qualifies you to apply. NASA recruits from a wide variety of backgrounds. I know people who have applied to be an astronaut who ask me, well should I do this or should I do that. And I said, you know, it doesn't matter. The basic requirements are you have to be in good health, and you have to have a good heart, I mean in a technical way, not to be a kind person, well that helps. Study something that you like and do well in it.

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.

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

Qian Xuesen, the father of the Chinese Space Program, studied in the United States, and he was a protégé of Theodore Von Carmen's at Cal Tech and helped start the jet propulsion laboratory there, and then he got caught up in the anti-communism wave and was accused of being a spy and was actually deported back to China where he built from nothing, their entire missile and space program. So, in a way, in a very real way, the United States in trying to protect so-called protect our secrets and throwing this guy out of the country, we helped seed and start the Chinese missile program.

There is no one area of chemical engineering that specifically helped me in my career as an astronaut, it was more the general education in engineering. Also, it was a very difficult and rigorous course. So, it made me strong and resourceful.

As far as Russia goes, they've been our partner for a long time now, since the early '90's. So you know, what's that, that's more than 15 years. And there have been times where things were a little tense, a little testy, but by and large, the partnership has been very successful. To give you two examples of that, when the Columbia accident occurred, the Russians supported us with their spacecraft faring our astronauts, including me, to the space station and also supplies.

The only two countries who will be able to launch people into space will be Russia and China. I've seen the Russian technology up close and I've had a chance to look at some of the Chinese technology. It's a very high level. They have good hardware and what China lacks is operational experience. But as they gain more experience, as they fly more missions, they'll catch up quickly. The U.S. does face the possibility of losing the lead in human space flight during this period of what we call the gap.