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ALSEPAbbrev. for Apollo Lunar Surface Experiments Package. Any of the experimental packages carried to the Moon by Apollos 11–17, set up by the astronauts, and left there to transmit information back to Earth. The content of each package differed, becoming more sophisticated as the program progressed. In the Apollo 17 ALSEP, a central station and thermal generator provided the main power; the experiments included an analysis of any residual atmosphere, detection and measurement of any lunar ejecta and meteorite impacts, measurement of any gravitational anomalies, lunar surface studies, and seismic measurements.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006