To try to really land a spacecraft really on another world is really difficult, and if we lose that ability, it's going to be heartbreaking.

As a kid at the World's Fair in 1965, I missed seeing the big global population clock roll over from 2,999,999,999 to 3 billion - I was really disappointed.

It's been heartbreaking. It's been emotionally just very difficult to handle.

What makes the United States great, the reason people wanted to live in the United States, move here still, is because of our ability to innovate.

You stop planetary exploration, those people who do that extraordinary work are going to have to go do something else.

I've always loved airplanes and flight. The space program was really important to me as a kid. I still have a photo of Armstrong and Aldrin on the moon in my living room.