Most people never believed in the real possibility of going to the moon, and neither did I until I was in my twenties.

Mars has a bit of air pressure; maybe we can build up that atmosphere to be a bit more accommodating to humans.

I really hate to be put in the position of trying to justify something, a decision that was made. I'm a military guy: when a decision is made, I go along with it, whatever the manufactured controversy and criticism.

The purpose of going to Mars is for humans to first begin to occupy, permanently, another planet in the solar system. The astronauts or pilgrims, whatever you might call them, are going to be very historically unique human beings.

As a student, I wrote English reports on science fiction.

The best way to study Mars is with two hands, eyes and ears of a geologist, first at a moon orbiting Mars... and then on the surface.

Armstrong described the lunar surface as 'beautiful.' I thought to myself, 'It's not really beautiful. It's magnificent that we're here, but what a desolate place we are visiting.'