the Apollo Lunar Module

The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo programme by Grumman to achieve the transit from cislunar orbit to the surface and back. The module was also known as the LM from the manufacturer designation (often pronounced "lem," from NASA's early name for it, Lunar Excursion Module).

The module was designed to carry a crew of two and rested on four landing legs. It consisted of two stages—the descent stage module and the ascent stage. The total mass of the module was 15,264 kg, with the majority (10,334 kg) in the descent stage. Initially unpopular because the many delays in its development significantly stretched the projected timeline of the Apollo programme, the LM eventually became the most reliable component of the Apollo/Saturn system, the only one never to suffer any failure that significantly impacted a mission, and in at least one instance (LM-7 Aquarius) greatly exceeded its design requirements.