--> Abstract: Revisiting the Apollo Lunar Surface Geophysical Experiments, by Seiichi Nagihara, Yosio Nakamura, and Lynn Lewis; #90124 (2011)

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Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA

Revisiting the Apollo Lunar Surface Geophysical Experiments

Seiichi Nagihara1; Yosio Nakamura2; Lynn Lewis3

(1) Department of Geosciences, Texas Tech University, Lubbock, TX.

(2) Institute for Geophysics, University of Texas at Austin, Austin, TX.

(3) , San Gabriel, CA.

From 1969 to 1972, the astronauts on the Apollo lunar missions deployed scientific instrument packages at all six of their landing sites. The first set of instruments on Apollo 11, powered by a solar array, lasted for only 20 earth-days. The rest, deployed at Apollo 12, 14, 15, 16, and 17, were powered by radioisotope thermal generators, and transmitted data until they were turned off in 1977. These instruments were collectively called the Apollo Lunar Surface Experiments Packages (ALSEPs). Geophysical instruments (seismometers, magnetometers, heat flow probes, gravimeters, etc.) were among those deployed as part of the ALSEPs. The ALSEP data received from the Moon were processed at the NASA Johnson Space Center (JSC) in Houston, and then were distributed to the scientists responsible for analyzing data from the individual instruments. The ALSEP data at JSC were also recorded on open-reel magnetic tapes for permanent archive. Forty years later, these datasets still represent the only direct, long-term, geophysical observations carried out on the surface of an extra-terrestrial body. It could be another decade or more, before NASA or any other space agency lands a new set of geophysical instruments on the Moon. That is why scientists continue to analyze the ALSEP data even today. In the last four decades, data analysis and interpretation techniques have improved. Computers have become much faster and more powerful. Finally, some scientists have found new ways for utilizing the data. Because of these continued efforts by the academic communities, our understanding of the lunar interior has kept improving. The ALSEP data have also been utilized for aiding the interpretation of data from the more recent, lunar-orbiting remote sensing instruments such as the Lunar Reconnaissance Orbiter. In addition, efforts are underway by largely volunteers to fully restore the raw data and the documentations of the ALSEPs. This presentation reviews such efforts by the modern researchers and volunteers to restore and further utilize the ALSEP data.