I inherited depression from my mother's side of the family. Her father committed suicide. She committed suicide the year before I went to the moon.

Mars is far more attractive as an outpost colony for earthlings than the moon is.

Computers allow us to squeeze the most out of everything, whether it's Google looking up things, so I guess that tends to make us a little lazy about reading books and doing things the hard way to understand how those things work.

The view from space is like having a globe on your desk -- it's a broadening experience.

Unless we are able to commit to a permanent growing settlement [on Mars], then I don't think just going there with humans and coming back is worth doing. The expense of planning to come back is like the people who left Europe to come to America and then to turn around and go back to Europe, it really doesn't make any sense at all.

History gets reinterpreted as time goes on. Many times, the participants are lost in the retelling of the story.

In my mind, public space travel will precede efforts toward exploration -- be it returning to the moon, going to Mars, visiting asteroids, or whatever seems appropriate. We've got millions and millions of people who want to go into space, who are willing to pay. When you figure in the payload potential of customers, everything changes.