NASA has appointed a review board to investigate the gyroscope problem. The telescope carries a total of six gyroscopes, but only three are needed to run the telescope. The others serve as backups.

During Hubble’s early years the gyroscopes died often, and replacing them was one of the main tasks of servicing missions. During the last and final servicing mission, in May 2009, astronauts installed six new gyroscopes. Two have since died, leaving a backup and three working gyroscopes, one of which expired on Friday.