Hubble telescope spends a week in 'safe mode' following mysterious computer error

The Hubble Space Telescope drifts above the horizon of the Earth, as it has since 1990.
The Hubble Space Telescope drifts above the horizon of the Earth, as it has since 1990. (Image credit: NASA JPL)

NASA's Hubble space telescope is cruising the cosmos in safe mode after its payload computer suddenly crashed on June 13 according to a NASA statement

The computer is responsible for coordinating and controlling all of the science instruments aboard the telescope — which means that, until technicians on the ground can get it up and running again, the world's most famous telescope is about as useful as the dead iPod in your junk drawer.

The good news is that NASA's 31-year-old satellite carries a backup computer on board, which technicians can switch on if the crashed computer proves too difficult to save. The bad news is that, after a week of troubleshooting, NASA techs still haven't figured out exactly what went wrong with the payload computer in the first place.

Related: 26 Cosmic Photos from the Hubble Space Telescope's Ultra Deep Field

"Initial indications pointed to a degrading computer memory module as the source of the computer halt," NASA officials wrote in the statement. "When the operations team attempted to switch to a back-up memory module, however, the command to initiate the backup module failed to complete."

A second attempt to bring both memory modules online on June 17 also failed, NASA added. The satellite carries a total of four memory modules, which either of the two payload computers can access at any time under normal conditions.

In a pinch, NASA can shuttle astronauts to the Hubble for a manual service job, as they did in 2009 during the STS-125 mission. On that mission, astronauts installed two new science instruments (a wide-field camera and an instrument for measuring ultraviolet light) onto the telescope and replaced some older pieces of hardware. That 2009 foray  was the fifth and final shuttle mission to the Hubble. With NASA's shiny new James Webb Space Telescope expected to launch later this year, there's no plan to manually service the Hubble again.

A glitchy software update sent the Hubble into safe mode as recently as March 2021, but was easily remedied, Live Science previously reported. While the Hubble was built in the late 1980s, NASA stressed that the telescope's science instruments are still in good working condition and are ready to resume their mission of mapping the cosmos as soon as the payload computer can be brought back online.

For now, there is "no definitive timeline" for bringing the computer back online, a NASA spokesperson told — but technicians have "multiple options available to them" for solving the problem. Let's hope this Hubble trouble ends on the double.

Originally published on Live Science.

Brandon Specktor

Brandon is the space/physics editor at Live Science. His writing has appeared in The Washington Post, Reader's Digest,, the Richard Dawkins Foundation website and other outlets. He holds a bachelor's degree in creative writing from the University of Arizona, with minors in journalism and media arts. He enjoys writing most about space, geoscience and the mysteries of the universe.