NASA is continuing to investigate why the instruments in the Hubble Space Telescope recently went into safe mode configuration, suspending science operations. The instruments are healthy and will remain in safe mode while the mission team continues its investigation.
Hubble's science instruments issued error codes at 1:46 a.m. EDT on October 23, indicating the loss of a specific synchronization message. This message provides timing information the instruments use to correctly respond to data requests and commands. The mission team reset the instruments, resuming science operations the following morning.
At 2:38 a.m. EDT, on October 25, the science instruments again issued error codes indicating multiple losses of synchronization messages. As a result, the science instruments autonomously entered safe mode states as programmed.
Mission team members are evaluating spacecraft data and system diagrams to better understand the synchronization issue and how to address it. They also are developing and testing procedures to collect additional data from the spacecraft. These activities are expected to take at least one week.
The rest of the spacecraft is operating as expected.