Astronauts train for certain missions, including Hubble service repair, by performing in special underwater tanks. This simulates a zero gravity environment.
Many widely known images of the galaxy have been taken by the Hubble Space Telescope, which turns 25 this year (time to rent a car!). NASA has created a fantastic video to discuss one of the later repairs to the Space Telescope Imaging Spectograph (STIS). It's a great example of geniuses at Johnson Space Center in Houston having to quickly come up with a solution when astronauts on a spacewalk could not correctly perform a repair.
The advances from fixing the Hubble's mirror will be rolled into the James Webb Space Telescope, as well as ... your eyes. Check out the following video to see how the technology is used to improve LASIK vision correction.
Check out more Hubble goodness here at the official NASA site, or the Hubble 25th anniversary site.