If you're a scientist, and you have to have an answer, even in the absence of data, you're not going to be a good scientist.
For me, I am driven by two main philosophies: know more today about the world than I knew yesterday and lessen the suffering of others. You'd be surprised how far that gets you.
I can't tell you how many people say they were turned off from science because of a science teacher that completely sucked out all the inspiration and enthusiasm they had for the course.
There's a lot to do in space. I want to learn more about the greenhouse effect on Venus, about whether there was life on Mars, about the environment in which Earth and the Sun is immersed, the behavior of the Sun.
The center line of science literacy - which not many people tell you, but I feel this strongly, and I will go to my grave making this point - is how you think.
As a scientist, I want to go to Mars and back to asteroids and the Moon because I'm a scientist. But I can tell you, I'm not so naive a scientist to think that the nation might not have geopolitical reasons for going into space.