I'll add to this that resolution is not the only metric by which you can judge a telescope. One major advantage that space telescopes have is that their environ

I'll add to this that resolution is not the only metric by which you can judge a telescope. One major advantage that space telescopes have is that their environment is much more stable, making calibration (for example, of the flux of a source) easier. On Earth, the weather changes from night to night, or even from minute to minute. You're effectively looking through a constantly changing, semi-opaque filter - the atmosphere. Ground-based telescopes have their own advantages, like the fact that they can be much larger and therefore can collect much more light. This is just to say that both space- and ground-based telescopes are useful, and have their own strengths.