Apollo Lunar Surface Experiments Package

Apollo Lunar Surface Experiments Package

The Apollo Lunar Surface Experiments Package (ALSEP) comprised a set of scientific instruments placed by the astronauts at the landing site of each of the five Apollo missions to land on the Moon following Apollo 11 (Apollos 12, 14, 15, 16, and 17). Apollo 11 left a smaller, temporary, package called the Early Apollo Scientific Experiments Package, or EASEP.

The instrumentation and experiments that would comprise ALSEP were decided in February 1966. Specifically, the experiments, institutions responsible, and principal investigators and coinvestigators were:ref|EAweb

* Passive Lunar Seismic Experiment, Massachusetts Institute of Technology, Frank Press; Columbia University, George Sutton.
* Lunar Tri-axis Magnetometer, Ames Research Center, C. P. Sonett; MSC, Jerry Modisette.
* Medium-Energy Solar Wind, Jet Propulsion Laboratory (JPL), C. W. Snyder; JPL, M. M. Neugebauer.
* Suprathermal Ion Detection, Rice University, J. W. Freeman, Jr.; MSC, F. C. Michel.
* Lunar Heat Flow Management, Columbia University, M. Langseth; Yale University, S. Clark.
* Low-Energy Solar Wind, Rice University, B. J. O'Brien.
* Active Lunar Seismic Experiment, Stanford University, R. L. Kovach; U.S. Geological Survey, J. S. Watkins.

The Apollo Lunar Surface Experiments Package (ALSEP) was built and tested by Bendix Aerospace in Ann Arbor, Michigan. The instruments were designed to run autonomously after the astronauts left and to make long term studies of the lunar environment. They were arrayed around a Central Station which supplied power generated by a radioisotope thermoelectric generator (RTG) to run the instruments and communications so data collected by the experiments could be relayed to Earth. Thermal control was achieved by passive elements (insulation, reflectors, thermal coatings) as well as power dissipation resistors and heaters. Data collected from the instruments were converted into a telemetry format and transmitted to Earth.

The ALSEP system and instruments were controlled by commands from Earth. The stations ran from deployment until they were turned off on 30 September 1977 due primarily to budgetary considerations. Also, by that time the power packs could not run both the transmitter and any other instrument, and the ALSEP control room was needed for the attempt to reactivate Skylab.


The ALSEP was stored in the LM's Scientific Equipment (SEQ) Bay in two separate subpackages. The base of the first subpackage formed the Central Station while the base of the second subpackage was part of the RTG. A subpallet was also attached to the second subpackage which usually carried one or two of the experiments and the antenna gimbal assembly. On Apollo 12, 13, and 14, the second subpackage also stored the Lunar Hand Tool Carrier (HTC). The exact deployment of experiments differed by mission. The following pictures show a typical procedure from Apollo 12.

List of Missions

Each mission had a different array of experiments.

Apollo 11 (EASEP)

As stated above, Apollo 11 did not leave a full ALSEP package, but left a simpler version called the Early Apollo Surface Experiments Package (EASEP). Since there was only one 2 hour 40 minute EVA planned, the crew would not have enough time to deploy a full ALSEP, which usually took one to two hours to deploy. Both packages were stored in the LM's SEQ bay.

The antenna gimbal assembly was stored on the first subpackage. The stool for the PSE, the ALSEP tools, carrybar, and the Lunar drill was stored on the subpallet. The HTC was stored on the second subpackage.

Apollo 14

Apollo 17


Encyclopedia Astronautica website, 14 February 1966 entry.


See also

* Lunar laser ranging experiment

External links

* [http://www.astronautix.com/craft/apoalsep.htm Astronautix Site]
* [http://www.myspacemuseum.com/alsep01.htm ALSEP Page @ myspacemuseum.com]
* [http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html NSSDC Apollo Page]
* [http://www.lpi.usra.edu/lunar/documents/NASA%20TM-X-58131.pdf Apollo Scientific Experiments Data Handbook]
* [http://www.lpi.usra.edu/lunar/documents/NASA%20RP-1036.pdf ALSEP Termination Report]
* [http://www.lpi.usra.edu/lunar/documents/NASA%20RP-1317.pdf Catalog of Apollo Experiment Operations]

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Apollo Lunar Surface Experiments Package — ALSEP Station ALSEP de la mission Apollo 16. L Apollo Lunar Surface Experiments Package (ALSEP) est un ensemble d instruments scientifiques installé par les astronautes des 6 missions du programme Apollo à la surface de la Lune entre 1969 et …   Wikipédia en Français

  • Apollo Command/Service Module — Apollo CSM The Apollo 15 CSM in lunar orbit Description Role: Earth and Lunar Orbit Crew: 3; CDR, CM pilot, LM pilot Dimensions Height: 36.2 ft 11.03 m …   Wikipedia

  • Apollo Guidance Computer — and DSKY Invented by MIT Instrumentation Laboratory Manufacturer Raytheon Introduced August 1966 …   Wikipedia

  • Apollo/Skylab A7L — Apollo 11 A7L space suit worn by Buzz Aldrin, and another worn by photographer Neil Armstrong in the visor reflection. The A7L Apollo Skylab spacesuit is the primary pressure suit worn by NASA astronauts for Project Apollo, the three manned… …   Wikipedia

  • Lunar Roving Vehicle — This article is about the Apollo rovers. For the Soviet robotic rovers, see Lunokhod program. For the planned Chinese robotic rover, see Chang e 3. The Lunar Roving Vehicle (LRV) or lunar rover was a battery powered four wheeled rover used on the …   Wikipedia

  • Lunar Module — Module lunaire Apollo Pour les articles homonymes, voir LEM et LM. Module lunaire du programme Apollo …   Wikipédia en Français

  • Lunar Laser Ranging Experiment — The ongoing Lunar Laser Ranging Experiment measures the distance between the Earth and the Moon using laser ranging. Lasers on Earth are aimed at retroreflectors previously planted on the Moon and the time delay for the reflected light to return… …   Wikipedia

  • Apollo PGNCS — The Apollo Primary Guidance, Navigation and Control System (PGNCS) (pronounced pings) was a self contained inertial guidance system that allowed Apollo spacecraft to carry out their missions when communications with Earth were interrupted, either …   Wikipedia

  • Apollo 15 — Missionsemblem Missionsdaten Mission: Apollo 15 NSSDC ID: 1971 063A Kommandomodul: CM 112 …   Deutsch Wikipedia

  • Apollo 14 — Missionsemblem Missionsdaten Mission: Apollo 14 NSSDC ID: 1971 008A Kommandomodul: CM 110 …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”