There's no guarantee that the United States will be around 200 years from now.

The moon I see now is the same moon I saw before. Except that before, when I looked at it, it was in anticipation of what it would be like when I got there. That's behind me now.

We must still think of ourselves as pioneers to understand the importance of space.

Pascal Lee is a true pioneer of Mars exploration.

Space is not just going up and coming back down again. Space is getting into orbit and being there, living there, establishing a presence, a permanence.

Mars, we know, was once wet and warm. Was it home to life? And what can living and learning to work on its rust-colored surface teach us about the future of our own planet, Earth? Answering those mysteries may hold the key to our future.

As time goes by, I'm increasingly impressed by how very special and timely it was that we got the degree of national commitment needed to put people on the Moon. For the first time, this nation was united in trying to develop an interplanetary capability. We've been trying to repeat that situation ever since.