Weve got to go [back to the moon]. But we dont want to stay too long. ... The ultimate goal is Mars.

If you want poets in space, you'll have to wait.

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.

The way I see it, commercial interests should manage a lunar base while NASA gets on with the really important task of flying to Mars.

They didn’t tell me I was going into space until after they locked the shuttle doors and started counting down.

My expertise is the space program and what it should be in the future based on my experience of looking at the transitions that we've made between pre-Sputnik days and getting to the moon.

I think humans will reach Mars, and I would like to see it happen in my lifetime.