Looks like the idea of sending robots to repair Hubble is gaining some steam. They wouldn’t be able to do everything you could do with a servicing mission, but they could install new instruments and gyros to keep the telescope running for quite a while longer. (Or not — if it’s deemed unfeasible, they might use a robot just to prepare the satellite for re-entry into the atmosphere.) It will be up to the engineers to build robots that can reliably do the job, which isn’t easy; but my bet is that it can be done. This challenge has actually energized a lot of folks at NASA, and fixing the Space Telescope is a goal everyone can agree on.