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.

Even though I knew I was inside the space shuttle getting ready to go fly, something about it wasn't completely real up until we got the call at about one minute to go, to close and lock our visors and start our oxygen flow. People often ask me, "What did it feel like right at the moment of launch?" And they're surprised when I tell them actually what I felt was relief. It wasn't like being anxious or scared or anything. It was relief because this is something I had wanted to do my whole life and now that the boosters had lit, we were on our way to go do it and nothing was going to stop us.

In 2006, I became the fist American to be allowed to go visit their astronaut center in China in Beijing. I think that it makes sense for the U.S. to work with China in the future and I hope to see, if the political atmosphere between the United States and China allow for us to do more cooperation together, especially in the area of human space flight. I think in the same way that it's help improve the relations between the U.S. and Russia; it would help to improve the relations between the U.S. and China.

The ultrasound that has application not only in space for a long mission or for a mission to the Moon or Mars, but also in remote areas on the Earth. Not even just - I'm not even talking about expeditions like to the Antarctic, but just a remote area, a small town somewhere. The local doctor is not going to know everything, and so if that person can link in with a diagnostic ultrasound to the hospital in New York City through the internet, then they can do a very quick diagnosis of something that's wrong with someone that's in this remote area.

The thing that you worry about your first flight or any flight is some kind of a problem coming up that is going to keep you from doing it. Whether it's being hit by a car, or getting in a bad accident, or coming down with some other medical disqualification. But once the boosters light, you're going.

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.

This was the first time we had two ex-Soviet Cosmonauts in Houston. A lot of us, including me, viewed it with some skepticism, because I grew up during the Cold War, so I had been hit with all this propaganda all along that their stuff wasn't that good, it wasn't that safe and we were so much better. What I found out later was that their space stuff was very good and good enough that I was certainly comfortable flying on their equipment. So, it was kind of a revelation of sorts as the years went by and I think it underscores the importance right now of international cooperation.