Posted: Wed, Apr 30, 2003, 2:12 PM ET (1812 GMT)

A gyroscope failure on the Hubble Space Telescope Tuesday has put the spacecraft into a temporary safe mode that should end by Wednesday evening. Gyro number 3 on Hubble failed early Tuesday after suffering several current spikes and spacecraft controllers were unable to revive it. The failure put the spacecraft into a protective safe mode, a standard procedure whenever the spacecraft has fewer than three operating gyros. The gyro in question had shut down twice before in similar circumstances but was successfully restarted; the gyro had been suffering problems for over a year. Controllers have activated a spare gyro and plan to have the spacecraft resume normal operations by Wednesday evening. Hubble requires three gyroscopes in order to maintain attitude control; two gyros have now failed.