Empty aluminum Apollo CM Side Hatch Counter Balance System Nitrogen Gas Cartridge, measuring approximately 9″ long and 1″ in diameter, labeled on the side with part numbers, “ME-282-0052-0001, 101060000242, 4425025-511, 6-26-69 225.55.” In fine condition. The canister was designed to hold nitrogen at 5000 psi to actuate the Apollo Command Module main hatch counterbalance system. The counterbalance system provided crew members assistance with opening the heavy outward swinging hatch in the event emergency egress was required while on the launch pad, and to aid with exiting the command module after splashdown. The counterbalance system was incorporated as part of the Unified Hatch design developed following the Apollo 1 fire.
