By 1931, after a few years' experience of flying scheduled airlines, those planes were operating at roughly 600 times the safety of the space shuttle. I look at safety not in terms of fatalities per passenger-mile, but when you get in and close the door, what is the risk of dying on this flight?

In 12 or 15 years, there will be routine, affordable space tourism not just in the U.S. but in a lot of countries.

There was a wonderful little short four-year time period when marvelous things happened. It started in 1908, when the Wright brothers flew in Paris, and everybody said, 'Ooh, hey, I can do that.' There's only a few people that have flown in early 1908. In four years, 39 countries had hundreds of airplanes, thousands of pilots.

I like to call the difference between research and development. Some people use that interchangeably. They'll say R&D. They're two totally different things.

We didn't know the importance of home computers before the Internet. We had them mostly for fun, then the Internet came along and was enabled by all the PCs out there.

Science is not about consensus, and consensus is not science.

I spent about seven years during the Vietnam War flight-testing airplanes for the Air Force. And then I went in and I had a lot of fun building airplanes that people could build in their garages. And some 3,000 of those are flying. Of course, one of them is around-the-world Voyager.