I remember it was hard to believe that I was taking a step onto the lunar surface.

When we can demonstrate that we can take off horizontally and put something into orbit, then we can begin to talk about increasing the amount of payload. But to say, 'I'm going to do that and put people into orbit' is a real leap.

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

Dwelling on an engine failure for a pilot as he rolls down the runway is NOT what he should be thinking about - it's obtaining a smooth liftoff! But in the back of his mind, he knows exactly what to do (or pretty much) and in many cases, if he's alone in the fighter aircraft, he has to leave that aircraft in an ejection seat in a big hurry!

I failed music when I was a teenager.

One of the major problems with long-term deep space human flight is the requirement for radiation shielding.

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.