[KevinTheOmnivore]

The military budget is bigger, but the defense of this country is one of the most basic, outlined purposes of our government. Flying people into orbit is not.

EDIT: I'd rather not get wrapped up in the military budget. It's huge, it's wasteful, and it's contentious. Point taken. However, my initial question was can anybody make a really rational argument for spending $16 billion on space exploration? If asked, most Americans might support a strong, expensive defense. I wonder though what their opinion might be of NASA's budget...?

Rather than comparing it to the military budget, how does it compare to the budget of say the NEA? I know $16 billion may be just a "drop in the bucket," but that's still money better used elsewhere.