NASA’s Chandra X-ray Observatory Is Back Online

October started out rough for NASA with the failure of the Hubble and Chandra observatories in the space of a week. However, Hubble is coming back online after the team got its backup gyroscope working again. Now, Chandra is working again after NASA engineers implemented a fix for its gyroscope issues. NASA can again scan the sky for X-rays.

Chandra is one of four missions in NASA’s Great Observatories program along with Hubble, the Spitzer Space Telescope, and the Compton Gamma Ray Observatory. The first three are still functional, but the Compton Gamma Ray Observatory failed in 2000 due to a bad gyroscope. Yes, these components are problematic, but you need them to determine which way the spacecraft is pointing via angular momentum. They have to spin continuously, and they simply wear out eventually.

Luckily, Chandra’s gyroscope issue was less severe than Hubble’s. With Hubble, NASA was unable to get a backup gyroscope online after the old one failed, so it might not have had the three it needed for full operation. Chandra reported an error and shut down unexpectedly, but NASA quickly tracked the cause to a bad gyroscope. On Oct. 10, one of the observatory’s gyros recorded three seconds of corrupted data, which threw off the onboard computer’s momentum calculation. The incorrect values caused safe mode to activate, preventing damage to the telescope.

NASA says it has successfully brought Chandra back to full operational capacity after activating a new backup gyroscope. The one that caused the error in the first place might still work fine, but the team has decided to place it in reserve since there were unused gyroscopes that definitely wouldn’t record corrupted data. NASA might attempt to reactivate the “bad” gyroscope in the future as a last resort to keep Chandra active as more hardware fails.

The Galactic Core of the Milky Way – composite image taken by Spitzer, Hubble, and Chandra telescopes

The team executed a series of maneuvers with the new hardware online to make sure Chandra could get its bearings correctly. Over the next week, NASA will fine-tune the spacecraft’s new gyroscope configuration and upload a new software patch that will adjust the computer configuration.

This quick fix means Chandra should remain functional for years to come — NASA believes the rest of its gyroscopes are in good working condition and have plenty of life left. Chandra started operating 19 years ago, so it’s already far outlived the original five-year mission profile. Even if it died tomorrow, it would still be an amazing success.

Now read: NASA May Have Fixed Hubble By Shaking It and Turning It Off and On, NASA Report Blames Boeing Mismanagement for SLS Delays, and Soyuz Crew Performs Ballistic Reentry After Booster Fails During Launch