Curiosity is the essence of human existence.

When you head on out to the Moon, in very short order, and you get a chance to look back at the Earth, that horizon slowly curves around in upon himself, and all of sudden you're looking at something that is very strange, but yet is very, very familiar, because you're beginning to see the Earth evolve.

I think America has a responsibility to maintain its leadership in technology and its moral leadership in the world, to explore, to seek knowledge.

We don't have the capability today to put a human being in space of any kind, shape or form, which is absolutely, totally unacceptable when we got the greatest flying machine in the world sitting down at Kennedy in a garage there with nothing to do.

One of the most important things about the geology on the moon is your descriptions of what you see, comparing them to things that you've seen on Earth so that the geologists and the scientists on the ground would know what you're talking about; and then take pictures of them.

Chemical propulsion is obsolete to go anywhere other than the moon. Three days - that's acceptable. But for Mars, we need propulsion technologies to get us there in, say, 60 days - then spend whatever length of time we want to spend and return when we want to come home.

I know the stars are my home. I learned about them, needed them for survival in terms of navigation. I know where I am when I look up at the sky. I know where I am when I look up at the Moon; it's not just some abstract romantic idea, it's something very real to me. See, I've expanded my home.