Cadmium-Sulfide Experiment

The cadmium-sulfide sensors are designed to detect micrometeoroid particles too fine to damage heavy metallic hardware, but presumably present in sufficient numbers to damage sensitive surfaces. Cadmium-sulfide detectors of similar construction but of much smaller area have been used successfully on Vanguard satellites and on Explorer VII. On Explorer XIII, the useful area is 3.1 square inches or about 80 times that of the Vanguard cells.