There should be an international lunar base. That is certainly doable.

We have the ability, at such high fidelity, to simulate the physical world through computers. But when the spiritual world or human behavior comes into play, we don't have a very good model for that at all.

There's a historical milestone in the fact that our Apollo 11 landing on the moon took place a mere 66 years after the Wright Brothers' first flight.

We need to begin thinking about building permanence on the Red Planet, not just have voyagers do some experiments, plant a flag and claim success. Having them go there, repeat this, in my view, is dim-witted. Why not stay there?

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.

I was motivated to improve the U.S. strategy of going back to the moon in 1985. That's a long time ago. Going back to the moon would be a great achievement for tourism adventure flights.

The g-forces increased and I wasn't able to continue to hold the camera against the window, so I had to lay it back against my chest, but still continued to photograph the re-entry until there was no more unusual visual effects of the energy in the atmosphere. And it was very comforting to understand that the people in Houston, the controllers, had very high confidence that we were on the right path.