For the last several years and culminating in six months in orbit next year, I've been training for my third space flight. This one is almost in a category completely different than the previous two, specifically to live in on the space station for six months, to command a space ship and to fly a new rocket ship.

Every decision you make, from what you eat to what you do with your time tonight, turns you into who you are tomorrow and the day after that.

By looking at the difference between perceived danger and actual danger, you can fundamentally change your reaction.

My optimism and confidence come not from feeling I'm luckier than other mortals, and they sure don't come from visualizing victory. They're the result of a lifetime spent visualizing defeat and figuring out how to prevent it. Like most astronauts, I'm pretty sure that I can deal with what life throws at me because I've thought about what to do if things go wrong, as well as right. That's the power of negative thinking.

"What's the next thing that's going to kill me?" is a mantra for pilots and astronauts.

Our role is to develop techniques that allow us to provide emergency life-saving procedures to injured patients in an extreme, remote environment without the presence of a physician.

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.