I felt pretty confident in relieving myself, since I had the urge.

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.

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 feel that this stands as a symbol of the insatiable curiosity of all mankind to explore the unknown.

Exploring Mars is a far different venture from Apollo expeditions to the moon; it necessitates leaving our home planet on lengthy missions with a constrained return capability.

The feeling of reduced gravity and the limitations of the space suit resulted in a slow-motion movement. Perhaps not too far from a trampoline, but without the springiness and instability.

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.