Persistence is very important. You should not give up unless you are forced to give up.

That's my lesson for taking a vacation: vacation will kill you.

The lessons of history would suggest that civilisations move in cycles. You can track that back quite far - the Babylonians, the Sumerians, followed by the Egyptians, the Romans, China. We're obviously in a very upward cycle right now and hopefully that remains the case. But it may not.

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.

You want to have a future where you’re expecting things to be better, not one where you’re expecting things to be worse.

There's a real opportunity to have a vertical takeoff and landing electric supersonic jet.

I’m nauseatingly pro-American. I would have come here from any country. The U.S. is where great things are possible.