The two main parts of the Apollo Lunar Module Modular Equipment Storage Assembly (MESA) locking and deployment mechanism. The locking and deployment mechanism measure approximately 12 x 6.5 x 3.5 and bears part numbers in orange-red text on the base, "Lot 3, LDW 280M17816, E0A6, MRR106498." The cable arm assembly measures approximately 10.5 x 7.25 x 3, and bears a faint part number that appears to begin, "LTM280M506." This part is missing a cam, otherwise the mechanism is complete. In very good to fine condition.
The MESA was located in Quad 4 of the Lunar Module Descent Stage. It lowered like a drawbridge when deployed by an astronaut by pulling the MESA deployment actuating handle located on the egress platform. As the cable pulled the cam, the cam disengaged a lock pin from a pivot arm. A key prevented the lock pin from interfering with its own disengagement from a locking post on the MESA. Once this was done, lunar gravity took over and deployed the MESA. Once deployed, the MESA served as a work station for the astronauts. In the earlier lunar landing missions (Apollo 11-14), the MESA was packed with equipment needed to explore and study the lunar surface. In the later 'J' scientific missions (Apollo 15-17), it also carried parts of the Lunar Roving Vehicle as well as supplies for the extended lunar stay time.
Terms and abbreviations used in our descriptions.