Almost everything worthwhile carries with it some sort of risk.

The Moon has given us months, tides and a destination that ever-beckons. It's time we build a rocket and go to stay.

As I have discovered again and again, things are never as bad (or as good) as they seem at the time.

I've been lucky enough to fly to space twice.

Anticipating problems and figuring out how to solve them is actually the opposite of worrying: it's productive.

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.

Decide in your heart of hearts what really excites and challenges you, and start moving your life in that direction. 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. Look at who you want to be, and start sculpting yourself into that person. You may not get exactly where you thought you'd be, but you will be doing things that suit you in a profession you believe in. Don't let life randomly kick you into the adult you don't want to become.