Astronauts are very professional and when they're preparing for launch, they prepare for it as the most serious endeavor of our lives.

Being an astronaut is a wonderful career. I feel very privileged. But what I really hope for young people is that they find a career they're passionate about, something that's challenging and worthwhile.

I think of it as a good opportunity to let, in particular, school kids know that this job and other interesting jobs in science and engineering are open to anyone who works hard in school and gets a good education and studies math and science. And that it's not just for a select group of people.

The ISS operates as the 'anchor customer' in low earth orbit to support new commercial space services, including delivery of cargo and, before long, crew transportation services.

There are lots of come-from-behind wins, games getting tied in the last period, teams going on to win. That, I think, tells the best story. Whether or not some teams have more grit, better chemistry, or more luck or more skill, it's still within the parameters. I think that makes for great storytelling and great interest for our fans.

Historical science is being left in the dust.

I've heard people on panels say, 'You must have a Web site. You need to tweet. Repeat the title of your book constantly,' and I just want to say, 'Shut up. Everything you're saying is wrong.' People will know instantly if your only motivation for tweeting is to sell books.

I'm a firm believer in science.