If you think about the energy that a rocket engine has to put out and all the fuel and you're sitting on top of like a bomb. And on the Space Shuttle, that big orange tank is filled with liquid hydrogen and liquid oxygen, the white cell rocket boosters on the sides are filled with solid propellant. There's a lot of energy in all those chemicals there and you've got to control it in a way so it doesn't explode. So, there's a lot of plumbing, a lot of valving, a lot of control systems, and it's a very complicated thing. So, how do you bring the price of that down?

One of the things, and the most exciting, actually definitely the most exciting thing is, having children. You know, I didn't have children before. I had been married only a year before my space station mission, so having three-year-olds is a whole new experience and that's the new adventure. It may sound funny because people have kids every day, but having your own kids, having my own kids, was as fundamentally, or maybe even more fundamentally life changing then even flying in space.

Cooperating in something as visible as space exploration and space flight can only improve relations between the two countries because what happens is, you're working on a common project in a very visible light and so, you're motivated to not have conflicts with each other in other areas. And bringing up China is a good example. In the early '90's, China got serious about wanting to launch astronauts into space and they were actually quite successful in launching many communication satellites. They went ahead and in 2003 they launched their first astronaut into space.

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.

You saw Britain back in the early days of sailing ships. They were the sea power, the controlled the seas and they had colonies all over the world and then you can look at history and watch the way that their empire kind of crumbled. I certainly don't want that to happen to the United States in space technology.

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 was an eight-year-old kid when I watched the first Apollo Moon Landing way back in 1969 and there was something about that moment that really stuck in my head. I'd always been interested in space and flying and I was building model rockets and model airplanes, but something about that moment, I can remember like it was yesterday watching the Apollo Lunar Lander approach the surface of the Moon and then later watching Neil Armstrong and Buzz Aldrin take the first steps on the Moon, and something that day started the dream for me that, hey, I want to be like those guys.