I'm not a scientist, I was not a good science student, I felt effectively alienated from science throughout my young life, and it was only when I became an adult that I began to really appreciate from a completely different angle the power of science.

When you're enlightened, you don't have to reference other people, because you yourself are enlightened. And that's a better Earth. People can make more informed decisions politically, culturally, personally.

The value of the space program is beyond science, it's beyond military; it's a cultural shift in how we think of our place in the universe.

So much of what we understand comes from knowing what something is and what that something used to be, which allows us to figure out, or at least imagine, what happened in between.

'As a fraction of your tax dollar today, what is the total cost of all spaceborne telescopes, planetary probes, the rovers on Mars, the International Space Station, the space shuttle, telescopes yet to orbit, and missions yet to fly?' Answer: one-half of one percent of each tax dollar. Half a penny. I'd prefer it were more: perhaps two cents on the dollar. Even during the storied Apollo era, peak NASA spending amounted to little more than four cents on the tax dollar.

I've always been interested in pop culture. Some of my colleagues think of pop culture as beneath them, or there's the ivory tower and then there's everybody else, and I never could buy into that wall that's been put up by so many people over the decades and even the centuries.

Private enterprise can never lead a space frontier. It's not possible because a space frontier is expensive, it has unknown risks and it has unquantified risks.