When I started working at NASA and understanding what the capabilities really were of the space station and the space program, one of the biggest draws for me was the ability to do experiments in space. We can do a number of experiments where gravity is actually a variable.

There's a world of insights to be gained into human health and disease by understanding how gravity and space radiation influence biology.

For long-duration exploration missions, NASA is looking for folks with a lot of operational, hands-on experience, people who have been in field-type situations such as military deployments. In my case, I worked in the Congo and in Biosafety Level 4 labs on smallpox.

You need nerves of steel if climbing aboard a rocket is your career path.

I'm a firm believer in science.

I didn't read comic books, growing up. I was more of a science fiction/fantasy novel guy. I loved reading Edgar Rice Burroughs' 'Tarzan' and that kind of stuff.

I've always been just as interested in making people think as I am in making them feel, and one of the things this scientific process allows me to do is make the audience look differently at dance.

The Jetsons had them in the 1960s. They were the defining element of 'Knight Rider' in the 1980s: cars that drive themselves. Self-driving cars appear in countless science fiction movies. By Hollywood standards, they are so normal we don't even notice them. But in real life, they still don't exist. What if you could buy one today?