The revolutionary breakthrough will come with rockets that are fully and rapidly reusable. We will never conquer Mars unless we do that. It'll be too expensive. The American colonies would never have been pioneered if the ships that crossed the ocean hadn't been reusable.

If you look at our current technology level, something strange has to happen to civilisations, and I mean strange in a bad way. And it could be that there are a whole lot of dead, one-planet civilisations.

The space shuttle was often used as an example of why you shouldn't even attempt to make something reusable. But one failed experiment does not invalidate the greater goal. If that was the case, we'd never have had the light bulb.

It's so insane the way rockets work today. It would be like if you got a plane and the way you get to your destination is you bail out with a parachute over the city in question and your plane crash lands somewhere. That's how rockets work today-with the exception of Falcon 9. This is completely bonkers.

The extreme difficulty of scaling production of new technology is not well understood. It's 1000% to 10,000% harder than making a few prototypes. The machine that makes the machine is vastly harder than the machine itself.

The release of atomic energy has not created a new problem. It has merely made more urgent the necessity of solving an existing one.