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.

The Americans are still the leaders in human space flight. I feel we have a danger here of kind of stagnating. We're kind of resting on our laurels and there's a danger going forward if we don't take bold steps to really support human space flight in this country that we could fall behind. After the space shuttle is retired, we're going to have a big gap, five to seven years, at least where we're not going to have the ability to send our own astronauts into space, we'll have to buy rides on the Russian Soyuz, and so that will be a pretty big step down for us.

Richard Branson is probably the most visible of the private commercial space guys, and what is venture, Virgin Galactic is about is sub orbital flight. That is, you'll see a spacecraft that looks more or less like an airplane and it will fly into space, but only spend about 15 minutes. It'll go up in a parabolic arc and then fall back down, and so the customers on that flight will only get about five minutes of weightlessness. They'll get to glimpse the horizon of the Earth, take a look at it before just before they start coming back down into the atmosphere.

I actually had four space flights altogether, three times on shuttles. My second flight was really unique for me because I was going back into space, first of all. The first one was like an appetizer at a nice dinner. You know, you want to go up and you want more. So, the second time I got into space, it was neat because I got to actually do two space walks.

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.

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.

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.