Astronauts have completed the most critical repair to the Hubble Space Telescope after a long struggle.

Mission specialists Mike Good and Mike Massimino put a refurbished pair of gyroscopes into the telescope after a new set refused to go in.

Besides the gyroscopes ? to orient it precisely ? Hubble got fresh batteries to ensure five more years of life.

Despite the setbacks, scientists said Hubble would function well, pointing to ever-distant objects in the cosmos.