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.

When you have a transportation system that the price of propellant is essentially negligible something is very wrong. If you look at any other transportation system, a car, a motorcycle, a train, an oil tanker, an airliner, you name it; about a quarter to a third of the operating cost is buying the propellant.

Usually the wacky people have the breakthroughs. The smart people dont.

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.

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.

The Russians did much bigger space launch vehicles for launching satellites and for getting men in orbit. They did that much sooner than America because America was very good at something else.

Everything looks nonsensical before it works.