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 grew up bilingual, I grew up speaking Chinese in the home, Mandarin Chinese with my parents, and I learned English because I was born and raised in the U.S. That really gave me an edge. I understand that, from the experts, if you grew up bilingual, your brain kind of gets wired to accept a new language. It was a very serious deal because not only did I have to learn Russian to a high degree in order to function as a necessary member of the crew, but also I knew that the Russians that came over that made an effort and had some success in learning English, those were the folks we trusted.

The training kicked in and we quickly went through our emergency procedures, I took manual control and I got the spacecraft under control and stopped about 50 meters from the space station. So, the net effect of the failure was that we were actually turning and speeding up towards the space station when we should have been slowing down, so it was quite a dangerous situation. But we got manual control, performed the first manual docking to the station at night. The training pays off. It was just automatic. We had our books out already, we went right to the right procedures and executed them.

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.

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.

One of my challenges was to try to photograph the Great Wall of China. And I did actually take some photos, but it was hard to discern the wall with the naked eye.

My running ambition is to keep doing it until I'm way past the point where I have any business running. Just to keep doing it throughout my whole life—to stay fit and feel good.