GALEX Status Update

July 9, 2009


Engineers and scientists are continuing the recovery procedure for the far-ultraviolet instrument on NASA's Galaxy Evolution Explorer. On May 29, the instrument experienced an overcurrent condition (too much current) and shut down. The project reviewed data from the incident and confirmed it had the same characteristics as three previous incidents occurring in 2005, 2006 and 2007.

Following procedures used in these previous incidents, the team began a process involving rapid on-off cycling of the detector's high-voltage while gradually increasing the voltage level over the course of several weeks. This process worked successfully for the three previous incidents. This time, the team noticed a slightly higher current than was expected, and the overcurrent increased as the higher voltage levels were set.

The team is currently executing new tests that will increase the voltage in real-time while monitoring the current in the detector. The results will help determine the time needed to increase the detector voltage to its nominal operating value while maintaining the current within a normal range.