My grounds for space exploration are simple, and probably unsatisfying for anyone besides myself: because it's space exploration. Personally, I've never been terribly impressed with arguments for economic resources, or even for seeding the human race off-world; to me, such things are secondary to learning about other worlds, and our place in the cosmos. I support a manned Moon or Mars mission in principle not because I want us to spread outward, but because I feel that for some tasks humans can teach us more than machines.

I think knowledge is a good in and of itself, regardless of any potential use. For instance, we'll almost certainly never use Element 114, but I think the knowledge gleaned about atomic physics from synthesizing it is a good.

In short, I support space exploration because I'm a curious individual, and I--and many others--want to know about what's out there. I've asked questions about the world my whole life, and space is just one more avenue for answering said questions.

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State