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.

We have self-assessment tools, computer-based tools to see how we are performing mentally in outer space and there's some also very interesting technology and work that's being funded by NRSBI to look at facial recognition to look at your patterns to see if you're experiencing stress or fatigue. It's a kind of thing that I think will gain acceptance with gradually. But it probably has more to immediate application in things like homeland security, and looking at facial recognition of people going through airports and things like that to see who's under stress.

The only two countries who will be able to launch people into space will be Russia and China. I've seen the Russian technology up close and I've had a chance to look at some of the Chinese technology. It's a very high level. They have good hardware and what China lacks is operational experience. But as they gain more experience, as they fly more missions, they'll catch up quickly. The U.S. does face the possibility of losing the lead in human space flight during this period of what we call the gap.

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.

I attended a big human space flight conference in Beijing and I was going as myself. And really, there weren't any NASA astronauts there, I was the only so-called American Astronaut there. We had astronauts from most of the other countries, certainly from Russia, from France, from Japan, several other countries, but it was a little bit odd because here we are at an international gathering of a lot of astronauts and I'm talking about somewhere upwards of 30 or so astronauts, and I'm the only American. And I wasn't even there in an official capacity.

The United States, Russia, and China are the only three countries in the world that can launch astronauts into space. Mostly in the U.S. you see some companies trying to launch private commercial people into space, but nobody's done it yet. The only private vehicle that's made it into space so far is Spaceship 1 in 2004, and that was an effort that was funded by one of the Microsoft founders, and he spent about $20 million to develop this spacecraft to do a sub-orbital flight. And it's not the same as going into orbit, but it was a huge first step.

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