NASA’s Chandra X-ray Observatory (CXO) is back online after a brief stint in safe mode last week.
Just before 10 a.m. EDT on Oct. 10, the telescope automatically entered a safe configuration, swapping critical hardware to back-up units and changing direction for optimal solar panel charging.
Officials were quick to point out that “all systems functioned as expected” in the abrupt transition, and “the scientific instruments are safe.”
Launched in July 1999, Chandra is one of the so-called Great Observatories—along with the Hubble Space Telescope, Compton Gamma Ray Observatory, and Spitzer Space Telescope.
A set of high-tech mirrors make Chandra sensitive to X-ray sources 100 times fainter than previous instruments of its kind.
Its initial five-year mission has long since expired; CXO has been floating through space for nearly 20 years—with no end in sight.
On Monday, NASA reported that a glitch in one of Chandra’s gyroscopes created a domino effect throughout the facility: A three-second period of bad data led the on-board computer to calculate an incorrect value for the spacecraft momentum, which ultimately triggered safe mode.
“The team has completed plans to switch gyroscopes and place the gyroscope that experienced the glitch in reserve,” the agency said in an update. “Once configured with a series of pre-tested flight software patches, the team will return Chandra to science operations which are expected to commence by the end of this week.”
The cosmic hiccup came just days after the Hubble Space Telescope entered safe mode, following the failure of one of its three active gyroscopes.
It’s not all doom and gloom for NASA’s collection of interstellar spyglasses: Earlier this year, researchers used Chandra’s powerful high-angular-resolution mirrors to capture a family portrait of stars in the cluster NGC 6231, some 5,000 light years from Earth.