One of the biggest concerns about going out beyond lower Earth orbit is the radiation. We find that exercise seems to counteract a lot of the negative effects of space flight, like bone loss and muscle atrophy and cardiovascular systems issues. We exercise two hours a day on the station, which is a huge hit out of your day. It's great for staying in shape, but you know, it cuts into the productivity of the crew and if you look at how expensive it is to get a crew into space, if we can keep them healthy and have them exercise, but spend less time doing it, we can get more done.

In a big picture sense, it's more national prestige that we're risking. You know, we are proud of our space program, but as we were talking earlier, the average American doesn't think that much about it right now. So, it may seem like something we could just give up and not really worry about it, but I think it starts creeping into the national psyche. If American astronauts have to hitch rides with the Russians or other nations in the future.

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.

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.

Space is very unforgiving business

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.

The Russians right now require a customer coming in and spending about six months or so in Russia and they have to learn some Russian. They have to learn some critical words so they can, in an emergency, at least have minimum communication with the Russian commander of the Soyuz. They also have to learn systems and I think this just evolved that way. They just thought, what is the minimum set of things we think we can train someone to be more or less competent in our systems? And so that's what these guys go through. So, it's not just like buying a ticket and getting on an airliner.