A hybrid human-robot mission to investigate an asteroid affords a realistic opportunity to demonstrate new technological capabilities for future deep-space travel and to test spacecraft for long-duration spaceflight.

I don't go through life verbalizing what I feel.

We could have human intelligence in orbit around Mars, building things there.

Neil Armstrong was the first man to walk on the moon. I am the first man to piss his pants on the moon.

When we set out to land people on the surface of Mars, I think we should as a nation, as a world, commit ourselves to supporting a growing settlement and colonization there. To visit a few times and then withdraw would be an unforgivable waste of resources.

I suggest that going to Mars means permanence on the planet - a mission by which we are building up a confidence level to become a two-planet species.

The pilgrims on the Mayflower landed at Plymouth Rock. To my knowledge, they didn't wait around for a return trip to Europe. You settle some place with a purpose. If you don't want to do that, stay home. You avoid an awful lot of risks by not venturing outward.