The optical device which the astronauts used for navigation while in the Apollo Lunar Module (LM) was an alignment optical telescope (AOT). The AOT was a periscope-type device that protruded through the top of the LM. The astronauts used AOT to make direct visual sightings and record precise angular measurements of pairs of celestial objects. This information was transferred to the Module's guidance computer, which determined the spacecrafts attitude and permitted the alignment of its inertial guidance system.
This functioning AOT was originally part of the Lunar Module Simulator used for mission training by the astronauts at the Kennedy Space Center. The Lunar Module Simulator, including the telescope, had been transferred to the Smithsonian in 1974 but, because of its size, remained in storage at the Kennedy Space Center for nearly 25 years. It was subsequently removed from the simulator's crew compartment to facilitate treatment by the NASM conservation staff. A replica was provided for the Lunar Module Simulator display.
Transferred from NASA to the Museum in 1975.
Transferred from the National Aeronautics and Space Administration, Kennedy Space Center.