I'm in favor of changing the destination of humans. There are a lot of manned missions that can be done, but not in the direction of the moon.

You can never tell when a commercial space venture will suddenly become viable.

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

Knowledge of the past and an optimistic view of the present give you great opportunities.

I understand that Detroit was a pretty rough place to grow up in the '70s and '80s.

I want to reach a new generation. That's why I am Twittering now. I have a BlackBerry, an iPhone and a Mac.

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