Mars could very well be a staging location for the resources of the asteroid belt. We have to learn how to get a payback somewhere, but it's beyond Mars that the real payoff will come from minerals.

For every winner, there's a loser. And that person didn't really need to lose. They just didn't understand the game plan.

When we can demonstrate that we can take off horizontally and put something into orbit, then we can begin to talk about increasing the amount of payload. But to say, 'I'm going to do that and put people into orbit' is a real leap.

Exploration is wired into our brains. If we can see the horizon, we want to know what's beyond.

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?

I'm in favor of changing the destination of humans. There are a lot of manned missions that can be done, but not in the direction of the moon.

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.