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

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.

There was a wonderful little short four-year time period when marvelous things happened. It started in 1908, when the Wright brothers flew in Paris, and everybody said, 'Ooh, hey, I can do that.' There's only a few people that have flown in early 1908. In four years, 39 countries had hundreds of airplanes, thousands of pilots.

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.

Confidence in nonsense is required.

A NASA astronaut and a Russian cosmonaut can't be creative. He has to follow a predetermined detailed checklist written by an engineer and if he gets a little creative he'll never fly again.

Everything looks nonsensical before it works.