Our three big emergencies are fire, loss of pressurization or contaminated atmosphere. Any of those things in a spaceship are very deadly and time critical. Everybody's trained, but I'm the commander of the ship, and it's up to me to decide.

The rough and ready improvisational quality to life on board the International Space Station is reminiscent of a long trip in a sailboat: privacy and fresh produce are in short supply, hygiene is basic, and a fair amount of the crew's time is spent just on maintaining and repairing the craft.

I wasn’t destined to be an astronaut. I had to turn myself into one.

In any new situation, whether it involves an elevator or a rocket ship, you will almost certainly be viewed in one of three ways. As a minus one: actively harmful, someone who creates problems. Or as a zero: your impact is neutral and doesn't tip the balance one way or the other. Or you'll be seen as a plus one: someone who actively adds value. Everyone wants to be a plus one, of course. But proclaiming your plus-oneness at the outset almost guarantees you'll be perceived as a minus one, regardless of the skills you bring to the table or how you actually perform.

When I stand on the edge of a cliff or right at the edge of a building or something, it's one of the few things that gives me kind of a deep, overwhelming, irrational fear where it affects my physiology.

I'm really looking forward to it, if you can imagine floating weightless, watching the world pour by through the big bay window of the space station playing a guitar; just a tremendous place to think about where we are in history.

I've had a chance to fly a lot of different airplanes, but it was nothing like the shuttle ride.