A Seismic Refraction System for Lunar Use

A miniaturized seismic refraction system has been constructed for possible use on early manned lunar landings. The detection system consists of three geophones, a three-channel amplifier, a geophone calibrator, and a logarithmic compressor system. A grenade launching device and an astronaut-held thumper staff are used as the sources of seismic energy. Seismic energy from the explosive sources is detected, amplified, logarithmically compressed, converted to digital form, and formatted for real-time transmission to earth. Total weight of the seismic detection system and ancillary electronics, exclusive of the explosive sources, is 6.25 lb.