The Apollo Active Seismic Data and Lessons for Pegs
A critical component of the lunar surface exploration program for the Apollo missions was the active seismic experiments. The active experiments were complementary to the passive seismic experiments. However, the active experiment included a source which was “fired” on command in a known location relative to the sensors. These sources included a thumper, a rocket-propelled grenade launched from a mortar, and an explosives package. The thumper was used while the astronauts were on the Moon while the grenades and explosive packages were fired after they had left. The resulting shot records were used to derive near surface velocity and thickness measurements of the Moon’s shallow geology.
These measurements are helpful in calibrating the objectives of PEGS, Planetary Exploration Geophysical System. PEGS is a prototype system for future lunar/Mars missions designed to acquire active seismic data and QC those data in near real time. The system has undergone three years of testing at Meteor Crater and a season of testing in Antarctica. The subsequent operational lessons and actual seismic data records may be compared to the Apollo experience and seismic records. Considerations of weight, safety, repeatability and deployment will be compared as well as source and receiver sampling considerations will be discussed based on the velocities and reflection times seen in the Apollo data.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009