Everyone who's been in space would, I'm sure, welcome the opportunity for a return to the exhilarating experiences there.

I was lucky enough to have been born on this planet earth, in this admirable country of the United States of America.

I think it's inevitable that there will be Earthlings establishing a presence on Mars. And I would say that it would certainly take place by 2050 or shortly thereafter.

There is very little doubt, in my mind, that what the next monumental achievement of humanity will be the first landing by an Earthling, a human being, on the planet Mars.

If you want poets in space, you'll have to wait.

A mind concerned about danger is a clouded mind. It's paralyzing.

Going to Mars would evolve humankind into a two-planet species.