In Mars, we've been given a wonderful set of moons where we can send continuous numbers of people.

Going back to the moon is not visionary in restoring space leadership for America. Like its Apollo predecessor, it will prove to be a dead end littered with broken spacecraft, broken dreams and broken policies.

I think we need to move to the moons of Mars and learn how to control robots that are on the surface. It's not the impatient way of getting there, but Mars has been there a long time.

Some things just can't be described. And stepping onto the moon was one of them.

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.

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

We have the ability, at such high fidelity, to simulate the physical world through computers. But when the spiritual world or human behavior comes into play, we don't have a very good model for that at all.