It's all interesting and cool, provides a ton of specialized and general careers and jobs for the US. I have a hard time spending $18.2 billionish on it though.
As far as govt spending goes, NASA gives the best ROI. We just take it for granted that you can get any channel, anywhere or use GPS with ease. There are countless applications in medical technology that have benefited from NASA technology. Also more efficient engines and energy saving technologies can trace their roots back to NASA research. There is no telling what future advancements could be realized if NASA were given a clear goal of human exploration and sufficient funding to make it happen. I'm a libertarian and about as cut spending to the bone as you can get but NASA is not one of those black holes of govt. spending. There has been too much new innovation and improvement in quality of life to ignore the benefits of investment in NASA.
I just don't understand the mentality of not wanting to know what's out there and having a better understanding of our place in space. It's extremely difficult to grasp the scale of space and it's kind of scary to think about how insignificant we as a species are. This is uncomfortable to some but we can't hold back our potential due to fear of the unknown. Our survival depends on continued enlightenment and advancement.