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

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.

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

The neatest thing about research and science is we don't necessarily know what's going to come down the pike. We think we know what we're working on. Oftentimes, discoveries are made when you're trying to discover something else. You end up accidentally discovering a different thing. So, one of those things might happen that enable us to have more efficient rockets.

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.

In 2006, I became the fist American to be allowed to go visit their astronaut center in China in Beijing. I think that it makes sense for the U.S. to work with China in the future and I hope to see, if the political atmosphere between the United States and China allow for us to do more cooperation together, especially in the area of human space flight. I think in the same way that it's help improve the relations between the U.S. and Russia; it would help to improve the relations between the U.S. and China.

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.