Apollo Lunar Surface Experiments Package

Apollo Lunar Surface Experiments Package ( ALSEP ) was the name given to a modular devices complex to carry out long-term scientific experiments on the lunar surface in the years 1969 until 1977. Data were sparked by telemetry to the ground.

ALSEPs were from Apollo 12 used by all Apollo missions, wherein the composition of the experiments varied. Apollo 11 led with a simpler device called EASEP (Early Apollo Scientific Experiments Package), which consisted of a powered from solar passive seismometer ( PSEP ), laser reflector ( LRRR ) and solar wind foil ( SWC). The ALSEP Apollo 13 was not used because the moon landing had to be abandoned at short notice, as the service module was heavily damaged by the explosion of an oxygen tank and the lunar module was used as emergency shelter.

The individual devices were designed and built by various institutes and research centers and were mostly designed for a lifespan of one to two years. The ALSEP was built by the astronaut in about 100 meters distance from the lunar module, so that the equipment would not be damaged by the re-emergence of the ferry. The common equipment were the following:

The scientific instruments included seismometers of different generations, magnetometer, spectrometer, ion detectors, heat flow meter and dust detectors were connected to the base station via cable. Added to this was in three cases of passive laser reflector, in the following compilations:

Note: ( 1) failed after only 14 hours of operation ( 2) The proposed borehole depth was not achieved because of the unexpectedly hard ground. ( 3) The HFE of Apollo 16 was inoperative after installation by tearing out a cable. A repair attempt was rejected due to time constraints.

Over time, there were several failures and disturbances. In particular, the LSM, the SIDE and the ALSEP Apollo 14 fell out several times. Receipt and evaluation of the ALSEP data were adjusted on September 30, 1977; At this time, nearly half of the equipment was still functional. The sender of the ALSEPs of Apollo 15 and 17 were further used by JSC for VLBI experiments until the summer of 1978, the base station of Apollo 15 and the following year the 17 down operations in Apollo due to depletion of RTGs. The three of the missions Apollo 11, 14 and 15 set out purely passive laser reflectors are not affected and are just like the two similar equipment of Russian origin used as before for the measurement of the lunar distance, see geodesy.

In 2011 it was announced that a new analysis of about 13,000 recorded moonquakes the seismometer to new results with respect to the lunar interior, in particular the detection of a liquid core, had led.

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