Space travel is the only technology that is more dangerous and more expensive now than it was in its first year. Fifty years after Yuri Gagarin, the space shuttle ended up being more dangerous and more expensive to fly than those first throwaway rockets, even though large portions of it were reusable. It's absurd.

Achieving something that has never existed in manned spaceflight and that is high volume and public access.

A NASA-funded study estimates that if the price of a ticket to space approached $100,000, close to a million people would buy one. That's a $100 billion industry. Microsoft cofounder Paul Allen gave me $20 million in startup funding to go after that market.

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.

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.

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.

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.