Reactivated Wide Field Camera 3 Once Again On The Job

After a period of downtime for repairs and recovery of the Wide Field Camera 3 instrumentation, the Hubble Space Telescope is on its way to full operation once again.

The telescope's systems were suspended following an anomaly on October 25, with select capabilities returning in a phased process. 

In early November, the agency began an investigation into the cause of Hubble's instruments going into an uncommanded safe mode configuration, suspending operations without notice. While healthy by all indications, the team decided further diagnostics were warranted, and left the systems safe until the issue to be assessed further. Throughout the month personnel narrowed down the problem to a possible issue with the internal systems responses to missed sync messages, as well as the payload computer's monitoring of instrumentation. Earlier this month, the Hubble team identified changes that could remedy the issue, and began the process of selective reactivation for the most pertinent instruments for future missions. 

The Hubble team chose to bring the most frequently called upon instrument online, the Wide Field Camera. Responsible for more than a third of the spacecraft's observation time throughout its lifespan, the camera is part and parcel of the Hubble's purpose in orbit. The engineers have begun preparation for a series of changes to the instrument parameters using ground simulators to improve reliability for the system, hopefully resulting in a system that could handle missed synchronization messages without interrupting normal operation in the future. If successful, the same changes could be applied to another Hubble instrument, the Cosmic Origins Spectrograph, to protect its sensitive far-ultraviolet detector. The process will take a few seeks to ensure successful integration when the time comes, and NASA says there are no further message losses like the initial anomaly. 

FMI: www.nasa.gov