I remember getting advice like, "Oh, do what interests you. Don't worry about tomorrow, live for today," kind of thing. And to a degree, you've got to do that, you've got to follow your passions. You've got to follow your dreams, but you also have to have a plan. You can't just say I'm going to do what interests me today and I'm not going to worry about tomorrow, that doesn't work. And anyone who's tried that I think quickly finds that out. Think about what turns you on, what do you dream about? But along with that, make a plan and work hard to make it happen.

My advice for an aspiring astronaut is to really follow your passion. I mean, study something that interests you, but also qualifies you to apply. NASA recruits from a wide variety of backgrounds. I know people who have applied to be an astronaut who ask me, well should I do this or should I do that. And I said, you know, it doesn't matter. The basic requirements are you have to be in good health, and you have to have a good heart, I mean in a technical way, not to be a kind person, well that helps. Study something that you like and do well in it.

I loved flying as much as I thought I would and continue to fly aircraft.

One day, people will be able to buy tickets to visit space.

The current market cost for a space flight, about a week in space and about six people have gone with the Russians so far to the International Space Station; it costs about $30 to $35 million. So, it's not for the faint of heart. But our own market studies that we've commissioned as well as some public market studies all indicate that there are somewhere around 20 or so individuals every year who have both the means and the interest to do this. So, the market is definitely out there.

There is no one area of chemical engineering that specifically helped me in my career as an astronaut, it was more the general education in engineering. Also, it was a very difficult and rigorous course. So, it made me strong and resourceful.

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.