I feel very strongly that SpaceX would not have been able to get started, nor would we have made the progress that we have, without the help of NASA.

The thing that's worth doing is trying to improve our understanding of the world and gain a better appreciation of the universe and not to worry too much about there being no meaning. And, you know, try and enjoy yourself. Because, actually, life's pretty good. It really is.

The extension of life beyond Earth is the most important thing we can do as a species.

Every mode of transport that we use - whether it's planes, trains, automobiles, bikes, horses - is reusable, but not rockets. So we must solve this problem in order to become a space-faring civilization.

It's important that we attempt to extend life beyond Earth now. It is the first time in the four billion-year history of Earth that it's been possible, and that window could be open for a long time - hopefully it is - or it could be open for a short time. We should err on the side of caution and do something now.

When you struggle with a problem, that's when you understand it.

You have to be pretty driven to make it happen. Otherwise, you will just make yourself miserable.