NASA’s Chandra X-ray Observatory has fully recovered from the safe mode it entered on Feb. 13.
NASA’s Chandra X-ray Observatory has fully recovered from the safe mode it entered on Feb. 13. The spacecraft resumed science operations on Feb. 24, with an observation of the supermassive black hole in the center of the galaxy, UGC 5745.
Chandra entered safe mode when a sensor that monitors the position of the Sun provided incorrect data. In safe mode, Chandra protects its critical hardware by pausing science operations, switching to back-up units, and changing its orientation so that it points perpendicular to the direction of the Sun. Once in that mode, Chandra waits for the operations team to identify and mitigate the fault that caused the safe mode and issue ground commands to restore normal operations.
To return Chandra to science, the team worked to address elevated temperatures, which reduced the sensitivity of the camera the spacecraft uses to find stars and orient itself (known as the “aspect camera”). On Feb. 17, the operations team succeeded in locking Chandra’s [a]gaze on stars and establishing an accurate pointing direction for the spacecraft, which was followed by maneuvers to a series of different pointings to cool the aspect camera and other critical components over several days. A set of commands that incorporates approximately a week of science observations, plus additional restrictions to reduce the likelihood of further safe mode events, was uplinked to the spacecraft on Feb. 24 to return Chandra to science operations.
The Chandra team then paused science observations on Feb. 26 to protect the instruments from radiation during a space weather event. The observatory resumed science on Feb. 28, and the spacecraft is healthy.
Feb. 17, 2023 — Chandra X-ray Observatory Status Update
On Feb. 13, NASA’s Chandra X-ray Observatory entered safe mode, likely because a sensor that monitors the position of the Sun provided incorrect data. The Chandra team is working toward full recovery of the spacecraft and a return to science observations. NASA will provide more information as it becomes available. Chandra has been operational and exploring the X-ray universe since 1999. To learn more about Chandra’s discoveries, visit https://www.nasa.gov/chandra.
Alise Fisher
Headquarters, Washington
202-358-2546
alise.m.fisher@nasa.gov
Molly Porter
NASA’s Marshall Space Flight Center
256-544-0034
molly.a.porter@nasa.gov