GALEX Status Update

December 2, 2009

GALEX Craft

Engineers and scientists are continuing to work on the recovery of the far-ultraviolet instrument on NASA's Galaxy Evolution Explorer. On May 29, 2009 the instrument experienced an overcurrent condition believed to result from field emission inside the detector. The project reviewed data from the incident and it appears to have the same characteristics as three previous far-ultraviolet incidents occurring in 2005, 2006 and 2007.

The project is performing a series of actions to recondition the detector for normal operations. In past recovery programs, the detector high voltage was cycled on and off at progressively increasing voltage levels to restore nominal behavior. The project is proceeding with this cycling process, however since the detector is not responding as it did in past events, they have several laboratory activities underway that are expected to aid in recovering the detector. These laboratory tests will be performed with spare instrument hardware before being exercised on the in-flight hardware to ensure detector safety.

The Galaxy Evolution Explorer's near-ultraviolet detector is working properly and is continuing uninterrupted science observations. Lost observations with the far-ultraviolet detector will be re-planned after the detector resumes operation.