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.

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 was born in the United States, I'm proud to be an American, I'm an American first. But obviously, I'm a Chinese-American. And growing up, my family, my parents, and I think rightly so didn't put us in Chinatown, didn't put us with our other ethnic group, but put us in mainstream America. They're thinking was that will help us assimilate into the mainstream and be a part of it. And it did. It certainly gave me tolerance of other people, of other races, of other ethnicities and I think that's helped make me a better person.

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.

The most important thing about an astronaut is you have to take for a given a person's done pretty well in school, has the intelligence and all of that to learn new systems and new things. But after that, the most important thing I think is being able to get along with others. Flexibility and teamwork, those issues because as we fly longer and longer in space, those are really important factors, even on short shuttle missions, those are important factors, to put a crew together that can work together effectively as a team, that can get along.

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

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.