By James Brophy , CNN Written by
NASA’s Hubble Space Telescope was shut down for three days last week because of a glitch with a key subsystem.
The telescope turned on Sunday, after repairs were made to the Wide Field Camera 3 (WFC3) which helps astronomers observe galaxies, said Hubble’s project scientist Edward Weiler in a NASA posting on Friday.
“In fact, WFC3 has experienced an uncharacteristic but very minor glitch,” said Weiler. “Spacecraft engineers assessed the problem and recommended the Hubble be turned on to perform tasks in its science catalog.”
NASA said its engineers are looking into a report of an unexplained loss of readings from the ultraviolet camera’s gyroscopes.
Hubble was originally scheduled to stay in safe mode from Thursday, until Saturday, April 7, allowing it to move higher into its orbit around Earth and more powerful thrusters could be used to restore the gyroscopes’ infrared sensitivity.
On Friday, April 6, the space agency began using a different set of thrusters to stabilize the telescope to help it avoid a glitch during its first days back in its proper operational orbit, NASA said.
“The tests are likely to take several days to complete,” the agency said.
The Wide Field Camera 3 (WFC3) as part of a Hubble Space Telescope science portrait of a distant universe from 2004-2009. NASA
Hubble made headlines in March of last year when it went into safe mode for two days while it was retrieving the ill-fated Green Bank Telescope that had shut down before its scheduled liftoff in 2011.
The telescope had been using WFC3 to peer deep into the universe, to take studies of the earliest galaxies and to catalog planets outside our solar system.
The telescope switched to a different camera while the repairs were performed and is now working normally.
Also last year, Hubble’s April and May missions were both delayed by technical problems, with April’s scheduled mission – Discovery – landing in May having to be switched to September.