The Transiting Exoplanet Survey Satellite (TESS) has resumed science observations following two separate safe mode events. The most recent incident occurred on January 15, 2026, with the satellite returning to normal operations on January 18, 2026.
January 2026 Incident Details
The January 2026 safe mode was triggered by a power anomaly. During a maneuver to point at a target, TESS's solar panels did not rotate to maintain their orientation towards the Sun. This resulted in a slow discharge of the satellite's batteries. As designed, TESS entered safe mode upon detecting the low-power condition. At the time of the incident, TESS was observing comet 3I/ATLAS and recommenced these observations on January 18.
April/May 2024 Incidents Details
Earlier, in 2024, TESS experienced another safe mode event on April 23, returning to operations on May 3. This safe mode was caused by a failure to properly unload momentum from the spacecraft's reaction wheels, a routine procedure for maintaining orientation. The propulsion system, necessary for this momentum transfer, had not been successfully repressurized following an earlier safe mode on April 8. The operations team rectified this issue, allowing the mission to return to normal science operations. The cause of the April 8 safe mode event remains under investigation.
About the TESS Mission
Operated by the Massachusetts Institute of Technology, NASA's TESS mission was launched in 2018. Its primary objective is to scan nearly the entire sky for exoplanets, which are planets beyond our solar system. Beyond exoplanet detection, TESS has also contributed to discoveries of other cosmic phenomena, including star-shredding black holes and stellar oscillations. All data collected by TESS is made publicly available through the Mikulski Archive for Space Telescopes.