The Rossi X-Ray Timing Explorer (XTE) Solar Array Anomaly

The XTE was launched December 30, 1995. Shortly after launch, it become apparent that the solar array was not performing as expected. On leaving shadow, the array exhibited many discontinuous drops in current output. The size of each of these drops was consistent with the loss of a part of a sell. The current decreases could not be caused by the loss of an entire circuit. This meant that the array may have had numerous cracked solar cells that opened as array got warmer. Studies performed on the array's qualification panel suggest that the cell cracks may have been cased by extensive tap testing performed on the array and that these cracks were undetectable at room temperature using usual inspection method.