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.

The leader of an Earth organization who makes a commitment to history - of humans living on Earth, to begin permanent settlement/occupation of not the moon, but of another planet - this leader will have a legacy for history that will supersede Columbus, Genghis Khan or almost any recognized leader.

Absolutely the United States should lead in space, for the survival of the United States. It's inspiring for the next generation. If we lose leadership, then we'll be using Chinese capability to inspire Americans.

We must still think of ourselves as pioneers to understand the importance of space.

We need to have people up there who can communicate what it feels like, not just pilots and engineers.

The energy varies with the square of the velocity, so if you need five times the velocity, that's 25 times the energy.

I participated with great honor in becoming one of the first to land on the moon, and now I am devoting and have devoted many years of my life to enabling Americans to lead international nations to permanence on the planet Mars.