Coming down under a parachute is quite different as well. You hit the ground pretty hard, but all the systems work very well to keep it from hurting, so it doesn't even hurt when you hit. It was a great experience to be able to do both.

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.

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

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

One day, people will be able to buy tickets to visit space.

The most interesting thing was looking out the window and taking photographs of different places on Earth.

There were different challenges along the way. Certainly the food shortage was unpleasant.

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.

But a lot of that kind of work is done pre-flight, coordinating efforts with the flight directors and the ground teams, and figuring out how you're going to operate together.

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.

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.

I spent a lot of my time working in the American module, and he would stay in the Russian segment working on his things, and we'd meet up at meal times. So it actually worked out very well.

I think it's good to have competition. Now we have a third country that can launch astronauts, so it's good for all of us. It makes us a little bit more competitive and wanting to be the leader.

I would say keep supporting space flight, keep telling the public and the politicians why it's important to advance science and explore the galaxy. I encourage the Japanese to keep doing what they're doing.

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.

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.

Our task was doing maintenance and repairs to keep the station in a good state for the return of the shuttle flights and resumption of major ISS construction.

Well, it's still a bit uncertain, but I will do the consulting, and I'll see how I can contribute. But I'm sure whatever I do will involve the space program. That's where my passion is.