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.

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

My own American Dream was to serve my country as best I could and make a difference in America - and in the world.

My favourite thing to do on this planet is to scuba dive.

The future is about wings and wheels and new forms of space transportation, along with our deep-space ambition to set foot on another world in our solar system: Mars. I firmly believe we will establish permanence on that planet. And in reaching for that goal, we can cultivate commercial development of the moon, the asteroid belt, the Red Planet itself and beyond.

There should be an international lunar base. That is certainly doable.

Look at what Silicon Valley has done - the advance of computers.