No one ever accomplished anything great sitting down.

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

Life off Earth is in two important respects not at all unworldly: you can choose to focus on the surprises and pleasures, or the frustrations. And you can choose to appreciate the smallest scraps of experience, the everyday moments, or to value only the grandest, most stirring ones.

Fatherhood is the unending imperfect task of turning yourself into your dad while secretly maintaining the unbridled elation of your boyhood

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.

Competence means keeping your head in a crisis, sticking with a task even when it seems hopeless, and improvising good solutions to tough problems when every second counts. It encompasses ingenuity, determination and being prepared for anything.

It’s not enough to shelve your own competitive streak. You have to try, consciously, to help others succeed.