Almost everything worthwhile carries with it some sort of risk.

Spaceflight isn't just about doing experiments, it's about an extension of human culture.

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.

Don't let life randomly kick you into the adult you don't want to become

Decide in your heart of hearts what really excites and challenges you, and start moving your life in that direction

Every single day you're the result of what you did on the days prior.

Focus on the journey, not on arriving at a certain destination.

Remember, nobody changes the world on their own.

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.

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

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

There is never a reason good enough to be out of alignment with peace.

The stars are numerous as the sand on the seashore.

Thankfully, dreams can change. If we'd all stuck with our first dream, the world would be overrun with cowboys and princesses.

The only thing that interests me is history - reviewing the past and making something out of it.

What is there that is illustrious that is not also attended by labor?

A little of everything and nothing thoroughly, after the French fashion.

Well, that's a 'fresher'. I'm going on break.

I engage and after that I see what to do.

Of immortality, the soul, when well employed, is incurious. It is so well, that it is sure that it will be well. It asks no questions of the Supreme Power.

Keep all your balls in the air.