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

By venturing into space, we improve life for everyone here on Earth - scientific advances and innovations that come from this kind of research create products we use in our daily lives.

When the time comes to start building deep space transports and refueling rocket tankers, it will be the commercial industry that steps up, not another government-owned, government-managed enterprise.

There are a lot of reasons for not doing something. And if humanity had come up with all the reasons for not doing something we wouldn't have spread across the Earth the way we have. There's a curiosity, and I would submit that that curiosity will put human beings on the surface of Mars.

I was the first Navy, Marine or Air Force person who had been an astronaut to return back to the Air Force. I had certain expectations about what would be a reasonable and desirable position to be assigned to after my years of service.

My Sunday mornings are spent in a recovery meeting in Pacific Palisades.

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