GALEX Status Update

June 27, 2008

GALEX Craft

Engineers and scientists with NASA's Galaxy Evolution Explorer are making progress determining the cause of a problem with the spacecraft's instrument processor, and the spacecraft may be fully operational by next week.

On June 13, the processor caused the science instrument to shut down. The Galaxy Evolution Explorer team now believes that the processor might have attempted to respond to erroneous signals (either a spurious interrupt signal or an invalid memory address), triggering it to halt. During its transit around Earth, the Galaxy Evolution Explorer is continuously subjected to elevated levels of radiation, which might have corrupted a portion of the contents of the computer memory.

Changes have been made to the instrument software to reduce the likelihood of a recurrence. Additional changes were also included to assist in identifying the specific area causing the processor to halt, should it happen again. The instrument is currently on and the temperature of the telescope is being adjusted.