Essentially every scientist, when posed with the question, "If you want to get science knowledge from Mars, do you want to send a geologist or do you want to send a robot?" Well, the real answer is, you can send 100 robots for the price of sending one geologist, so let's send 100 robots to 100 different locations, and then we would all benefit. So that's the answer you would get. And I agree with that answer.

You will never find scientists leading armies into battle. You just won’t. Especially not astrophysicists -we see the biggest picture there is. We understand how small we are in the cosmos. We understand how fragile and temporary our existence is here on Earth. We understand there are bigger problems we need to solve as a species than what God you pray to.

The greatest explorer of recent decades is not even human.

If NASA were advancing a space frontier there would be challenges you've never seen before. You have to be creative and you have to patent some new idea. You get to Mars...well, how do we get the water from the soil? I gotta invent a new device that will do that. And the carbon dioxide in the atmosphere, how can we use that? Can we breathe the oxygen from the carbon dioxide?

The worst thing that ever happened to America was the 19th Amendment.

If you want a nation to have space exploration ambitions, you've got to send humans.

One of the greatest features of science is that it doesn't matter where you were born, and it doesn't matter what the belief systems of your parents might have been: If you perform the same experiment that someone else did, at a different time and place, you'll get the same result.