NASA’s Hubble Space Telescope lives: switch to backup hardware fixes glitch


The NASA/ESA Hubble Space Telescope during deployment in 1990.

NASA/Smithsonian Institution/Lockheed Corporation

NASA’s beloved Hubble Space Telescope has been facing one of its greatest challenges. A technical glitch left it in safe mode for over a month. This week, NASA said it finally tracked down the source of the issue and tried a new fix, and it seems to have worked.

“NASA has successfully switched to backup hardware on the Hubble Space Telescope, including powering on the backup payload computer, on July 15,” the space agency announced on Friday.

The telescope has been in service for over 30 years. The Hubble team had been looking at the payload computer — hardware dating back to the 1980s — as the potential source of a memory problem. “A series of multi-day tests, which included attempts to restart and reconfigure the computer and the backup computer, were not successful, but the information gathered from those activities has led the Hubble team to determine that the possible cause of the problem is in the Power Control Unit,” NASA said.  

As with the payload computer, the PCU is part of Hubble’s Science Instrument Command and Data Handling unit. The PCU is responsible for supplying a constant and steady source of electricity to the computer and its memory. Hubble is equipped with a lot of backup systems, including a spare PCU. 

Since the issue cropped up on June 13, Hubble’s science work has been stalled. The switch to backup hardware should give the telescope a new lease on life. “The Hubble team is now monitoring the hardware to ensure that everything is working properly,” said NASA. It will take over a day to get the science instruments out of safe mode before normal science operations can resume.  

NASA operates Hubble in partnership with the European Space Agency. “We’re extremely happy to announce that Hubble is back online!” ESA’s Hubble team tweeted on Friday. “Congratulations to the entire team that worked around the clock to make this happen.”

There has been concern for the aging telescope. Its successor, the much-delayed James Webb Space Telescope, is still here on Earth, waiting for a possible late-2021 launch.

Hubble has weathered many technical glitches in its time, and it’s looking like the venerable telescope will persevere through this latest one. Hold on, universe, Hubble is coming back.

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