The Apollo Lunar Module (LM, also known as LEM (Lunar Excursion Module), is a lander, part of the Apollo spacecraft, built for the American Apollo program by the Grumman Corporation for a two-man crew for delivery from lunar orbit to the lunar surface and back. ”Six of these modules successfully landed on the Moon in 1969-1972.The main purpose is to deliver astronauts to the moon; unmanned flights and controlled near-earth flights were also performed; Apollo modifications were used to deliver three crews to the Skylab orbital station and to dock with the Soviet Soyuz-19 spacecraft under the Soyuz-Apollo program. The spacecraft consists of a main unit (crew compartment and engine compartment) and a lunar module (landing and takeoff stages), in which astronauts land and start from the Moon.