It's a fixer-upper of a planet but we could make it work.

The United States is definitely ahead in culture of innovation. If someone wants to accomplish great things, there is no better place than the U.S.

An asteroid or a supervolcano could certainly destroy us, but we also face risks the dinosaurs never saw: An engineered virus, nuclear war, inadvertent creation of a micro black hole, or some as-yet-unknown technology could spell the end of us.

I do think there is a lot of potential if you have a compelling product and people are willing to pay a premium for that. I think that is what Apple has shown. You can buy a much cheaper cell phone or laptop, but Apple's product is so much better than the alternative, and people are willing to pay that premium.

It's just mind-blowingly awesome. I apologize, and I wish I was more articulate, but it's hard to be articulate when your mind's blown-but in a very good way.

My vision is for a fully reusable rocket transport system between Earth and Mars that is able to re-fuel on Mars - this is very important - so you don't have to carry the return fuel when you go there.

It is despairing to consider that the cost and reliability of access to space have barely changed since the Apollo era over three decades ago. Yet in virtually every other field of technology, we have made great strides in reducing cost and increasing capability.