I suggest that going to Mars means permanence on the planet - a mission by which we are building up a confidence level to become a two-planet species.

The final frontier may be human relationships, one person to another.

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.

I'm not in favor of just taking short-term isolated situations and depleting our resources to keep our climate just the way it is today.

Retain the vision for space exploration. If we turn our backs on the vision again, we're going to have to live in a secondary position in human space flight for the rest of the century.

We're number one on the runway.

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.