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

Climate has been changing for billions of years.

Mars could very well be a staging location for the resources of the asteroid belt. We have to learn how to get a payback somewhere, but it's beyond Mars that the real payoff will come from minerals.

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.

Timing has always been a key element in my life. I have been blessed to have been in the right place at the right time.

The biggest benefit of Apollo was the inspiration it gave to a growing generation to get into science and aerospace.

We need the next generation to be motivated and to push technological boundaries, to seek out new innovations.