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 package called the Early Apollo Scientific Experiments Package, or EASEP.
The Apollo Lunar Surface Experiments Package (ALSEP) system consists of two sub-packages and a fuel cask assembly. One sub-package contains three of the
experiment subsystems, the data subsystem, and a portion of the electrical power subsystem. The other sub-package contains the astronauts hand tools that they used
for geological sampling, one of the experiment subsystems and the remainder of the electrical power subsystem. The fuel cask assembly is the container for the radio
active fuel capsule. The two ALSEP sub-packages will be mounted within the scientific equipment bay of the Lunar Module for their trip to the Moon.
The ALSEP was stored in the Lunar Module'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).
