Originally posted by: arcas
Hubble is terribly outdated and has been far surpassed by ground-based telescopes. Adaptive optics, where you deform the mirror in real-time, has largely solved the problem of atmospheric distortions. Hubble's only advantages these days are: it doesn't have to deal with daylight or light pollution, there are no cloudy nights in space and with an appropriate camera it can image in wavelengths that are blocked by our atmosphere (say, ultraviolet).
For visual wavelengths, there are several earth-based telescopes that have far greater resolution than Hubble. For example, the huge Keck 1 and Keck 2 telescopes in Hawaii each have a 10 meter deformable mirror and, individually, they each offer greater resolving power than Hubble. But the plan is for Keck 1 and Keck 2 to be linked together to form the largest optical interferometer ever built. When that's finished, it will have much higher resolution; enough to view planets orbiting other stars. And here's the kicker: these telescopes cost less than the cost of a single Hubble repair mission.
I do fear that the renewed push for a moon landing and then Mars will have an adverse effect on other NASA projects. NASA does have a more advanced space telescope in development which isn't scheduled for launch for another 3 or 4 years. Hopefully projects like this aren't simply canned because they don't fit this administrations new vision. Remains to be seen how this'll play out.