Everything looks nonsensical before it works.

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

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.

In the coming era of manned space exploration by the private sector, market forces will spur development and yield new, low-cost space technologies. If the history of private aviation is any guide, private development efforts will be safer, too.

I have a hunch the most important reason we're going to space is not known now.

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.

We'll go back to the moon by not learning anything new.