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.

Airplanes were invented by natural selection. Now you can say that intelligent design designs our airplanes of today, but there was no intelligent design really designing those early airplanes. There were probably at least 30,000 different things tried, and when they crash and kill the pilot, don't try that again.

NASA is doing nothing but development. They're not doing research in manned spaceflight at all and I see no reason for them to do that because we already know that it will work and we already know exactly how it will work.

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.

I believe that research, that you can claim that you're doing research only if half of the people, and I'm talking about half of the experts, believe that the goal is impossible.

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

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.