Everything looks nonsensical before it works.

The criticism is, once I get something flying, I lose interest in it.

I drove an electric car for seven years because of its advanced technology, not because I have any concerns about energy resources. I have none at all. And when environmentalists say that global warming is dangerous, unprecedented and that we'll have a tipping point for atmospheric carbon dioxide, it's just nonsense.

To allow public access to orbit, we would need breakthroughs that would lower the cost by a lot more than an order of magnitude and increase safety by a factor of 100 as compared to every launch system used since the first manned space flight. I think airborne launch will be a significant part of the safety solution.

The photographs of space taken by our astronauts have been published all over the place. But the eye is a much more dynamic mechanism than any camera or pictures. It's a more exciting view in person than looking at the photographs. Of course, I personally am sick and tired of hearing people talk like that: I want to see it myself!

Within 25 years, virtual reality meetings will be essentially transparent to being there in person. Once we can do this, the idea of climbing into an aircraft, and burning up huge quantities of fossil fuels to propel our bodies and briefcases full of papers, will seem absolutely backward.

At various times over 20 years, I did preliminary designs for aircraft like the Stratolaunch. For that whole time I was encouraging us to do something that almost everyone else felt you could not do.