The Russians have been flying long duration crews since the early '70's. And in the early days, they've ended at least two missions early because of conflicts within the crew. So, they learned early on the importance of studying this and making sure you put the right crew together. Since we began our work together on the International Space station with the Russians in the early 2000's, NASA has started to learn the importance of this kind of work. And so, I think it's important work and we are not fully onboard and recognize it as important.

Getting into a space suit and going outside, to me, getting your peripheral vision involved and looking at the Earth was a whole different experience than looking through the window. And it's kind of the same on earth. If you're driving in a car and you see like a beautiful sunset or landscape, it looks so much better if you stop and get out and kind of take it all in and that's kind of what it's like doing a spacewalk.

Because we didn't cooperate with China, we gave them motivation to develop their own capability. You know, they developed a very capable rocket system, very capable spacecraft. And if we don't cooperate with them in the future, they're going to develop more capable systems. If we're working together on a highly visible project, there is going to be much less, or there is going to be motivation for each country to not get into a conflict or any kind of tension in the military sense.

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

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.

When Russians were having troubles, the Space Shuttle supported the Space Station Mir bringing up much needed supplies and replacements, critical spares, really. That they were able to keep their space station going for much longer than they would have without us. So, I think that shows the value of international cooperation.

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.