Satellite, Explorer 46: Meteoroid Technology Satellite, Backup

This is a refurbished backup of the Meteoroid Technology Satellite, Explorer 46. It was designed to provide data on the frequency and penetration energy of meteoroids and micrometeoroids in near-earth orbit. The original consisted of a hexi-cylindrical bus covered with solar cells. Meteoroid impacts were detected and measured using bumper panels that extended after launch and gave the satellite a windmill-like appearance. The central hub of the satellite carried the velocity and impact experiments. When the bumper targets were extended from the satellite, it had an overall width of 23 feet (7.015 m).

The satellite was launched on August 13, 1972 from Wallops Station in Virginia aboard a Scout rocket into an orbit that ranged from 302 to 494 miles. Twenty meteoroid impacts were recorded by the bumper panels through December 1972. A set of capacitor detectors recorded over two thousand micrometeoroid hits over the same period. This backup was rebuilt by technicians at NASA's Langley Research Center. It was transferred to NASM by NASA in July 1976.