There may be aliens in our Milky Way galaxy, and there are billions of other galaxies. The probability is almost certain that there is life somewhere in space.

Everyone who's been in space would, I'm sure, welcome the opportunity for a return to the exhilarating experiences there. For me, a flight in a shuttle, though most satisfying, would be anticlimactic after my flight to the moon. Plus, if I pursued a flight myself, people would think that was the reason I am trying to generate interest in public spaceflight. And that's not the purpose - I want to generate interest in long-range space exploration.

I think the public needs to be reminded just how much inspiration and intention was given throughout the world to be bold, to send human beings to the moon in the '60s and the '70s. It's important now to bring together the nations that weren't able to do it then and help them do it. We need to move forward.

Certainly, I've never wanted to live on past achievements.

Sending a couple of guys to the Moon and bringing them back safely? That's a stunt! That's not historic.

Russia perhaps is still entertaining the possibility that the moons of Mars might have access to ice or water.

You can never tell when a commercial space venture will suddenly become viable.