Well, NASA's crippled Kepler space telescope, launched in 2009, is officially beyond repair. Two of the four wheels used to align the telescope have failed over the past year, and NASA engineers haven't been able to get either of them working again. NASA announced today that attempts to fully restore the spacecraft have ceased.
This may not spell the total end of Kepler's mission, though. NASA will still try to figure out a way to use the spacecraft for whatever scientific research it can manage in its current condition, with one reaction wheel short of a workable set. The agency put out a call for scientific white papers proposing alternate uses for Kepler a few weeks ago.
Kepler was originally designed to hunt for Earth-sized exoplanets in the galaxy, and during its initial four-year mission, it found more than 100. Its mission was extended in April 2012, and scientists are still sorting through all the data it has sent back in the meantime.