By refocusing our space program on Mars for America's future, we can restore the sense of wonder and adventure in space exploration that we knew in the summer of 1969. We won the moon race; now it's time for us to live and work on Mars, first on its moons and then on its surface.

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.

Like actors and writers who are on and off again in terms of employment, I had a very unstructured life.

Does it make sense for the U.S. to expend hundreds of billions of dollars to mount a new Apollo-style program to return to the moon? Or have we blazed that trail? Shouldn't we help other nations achieve this goal with their own resources but with our help?

The way I see it, commercial interests should manage a lunar base while NASA gets on with the really important task of flying to Mars.

I don't believe any pair of people had been more removed physically from the rest of the world than we were.

We'll get to the details of what's around here, but it looks like a collection of just about every variety of shape - angularity, granularity, about every variety of rock.... The colors - well.... There doesn't appear to be too much of a general color at all; however, it looks as though some of the rocks and boulders are going to have some interesting colors to them. Over.