I think both the space shuttle program and the International Space Station program have not really lived up to their expectations.

Long-term, I see robotics prevailing on the moon. . . . The most important decision we'll have to make about space travel is whether to commit to a permanent human presence on Mars. Without it, we'll never be a true space-faring people.

Absolutely the United States should lead in space, for the survival of the United States. It's inspiring for the next generation. If we lose leadership, then we'll be using Chinese capability to inspire Americans.

Heavy lifting doesn't need to be heavy spending if we do the job right.

People communicate in Twittering ways. I've learned how to do that.

I've led a life of such structured discipline and always had a goal in mind of knowing what I was doing, from West Point to the Air Force combat, MIT, looking for new things to study and get involved in. And then I got into the space program, and how disciplined can you get?

To appropriately respond to an emergency requires a very clear mind, to cooly analyze what the observations are and how to fix it.