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

It's good to have a fear of heights. I mean, it's kind of crazy not to because if you just lean out a little bit and there's a gust of wind or somebody bumps you or something and you fall, you're splat.

If you start thinking that only your biggest and shiniest moments count, you're setting yourself up to feel like a failure most of the time.

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.

The cool things about space is when you put your pants on here, you can put them on two legs at a time.

In my experience, fear comes from not knowing what to expect and not feeling you have any control over what’s about to happen. When you feel helpless, you’re far more afraid than you would be if you knew the facts.

Other anatomical changes associated with long-duration space flight are definitely negative: the immune system weakens, the heart shrinks because it doesn't have to strain against gravity, eyesight tends to degrade, sometimes markedly (no one's exactly sure why yet). The spine lengthens as the little sacs of fluid between the vertebrae expand, and bone mass decreases as the body sheds calcium. Without gravity, we don't need muscle and bone mass to support our own weight, which is what makes life in space so much fun but also so inherently bad for the human body, long-term.