So now NASA is considering using robots to repair Hubble instead of a manned mission. The primary reasoning being that it is safer and more cost effective. While laudible reasons, I think that using robots should be the preferred method for a completely different reason.
Let's face it, putting a man up there and doing repairs, maintenance and upgrades isn't technically challenging (though it is rocket science). We've done it all before, and doing it again really doesn't teach us anything or push the boundaries of space exploration for us. Using a robot, on the other hand, is a new advancement. We've not done it before and by pursuing it we'll be improving our ability to understand the complexities of the job. THis will further our ability to make robots that repair other craft and machines even further from Earth.
So by all means, scrap an astronaut visit. It's costly, risky, and just plain boring. If we want to push further in our abilities to explore space, we need to push our abilities to do work locally, and in this seemingly rare case what is good for science may also be good politically.