What keeps me up at night? Probably most, thinking about the future for my kids. It sounds kind of funny, but not so much what they're going to do, but how as a parent, how my wife and I as parents, how best we should prepare them for the world. And I know everybody does this, I think everybody stays up at night thinking about the best thing for their kids, and astronauts are no different.

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

Tinkering is something we need to know how to do in order to keep something like the space station running. I am a tinkerer by nature.

The space station mission was kind of the culmination of all of my experience of being a NASA Astronaut, so it had brought all of my previous experience into play. I had to learn the Russian language to a fluent level so that I could function as the co-pilot of the Soyuz Spacecraft that we flew up and back from the space station. And then the challenge of being the Commander of the whole expedition, a six and a-half month flight aboard the international space station. I felt the burden of the whole mission on my shoulders, which was fine, and fortunately everything did go well.

I was born in the United States, I'm proud to be an American, I'm an American first. But obviously, I'm a Chinese-American. And growing up, my family, my parents, and I think rightly so didn't put us in Chinatown, didn't put us with our other ethnic group, but put us in mainstream America. They're thinking was that will help us assimilate into the mainstream and be a part of it. And it did. It certainly gave me tolerance of other people, of other races, of other ethnicities and I think that's helped make me a better person.

What keeps me up at night? Probably most, thinking about the future for my kids. It sounds kind of funny, but not so much what they're going to do, but how as a parent, how my wife and I as parents, how best we should prepare them for the world. And I know everybody does this, I think everybody stays up at night thinking about the best thing for their kids, and astronauts are no different.

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.