Nobody ever asks who was the seventh person on the Moon. The only thing they know is who's number one and who's number two. Does anybody know who the last man was?

If you want to say that the sky is black, and if I'm there, even if I fall back down again, I will be weightless for a period of time - maybe that's the definition of space.

I came to dedicate my life to opening space to the average person and crafting designs for new spaceships that could take us far from home. But since Apollo ended, such travels were only in our collective memory.

As time goes by, I'm increasingly impressed by how very special and timely it was that we got the degree of national commitment needed to put people on the Moon. For the first time, this nation was united in trying to develop an interplanetary capability. We've been trying to repeat that situation ever since.

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

My first inclination is to be a bit skeptical about the claims that human-produced carbon dioxide is the direct contributor to global warming.

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