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.

I would say keep supporting space flight, keep telling the public and the politicians why it's important to advance science and explore the galaxy. I encourage the Japanese to keep doing what they're doing.

One of my challenges was to try to photograph the Great Wall of China. And I did actually take some photos, but it was hard to discern the wall with the naked eye.

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

Two years ago, China tested an anti-satellite weapon that actually caused quite a bit of controversy and one of the controversies is that by blowing up a satellite, you are creating more space debris which is a hazard to satellites and spacecraft in lower Earth orbit and if they had been a partner, you'd have to do an experiment, and if they had been a partner in the international space station, would they have really done that test? They would have really thought twice about creating that tension between the countries and potentially endangering a project that they were a part of.

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.