A lunar module is a lunar lander designed to allow astronauts to travel between a spacecraft in lunar orbit and the lunar surface. As of 2021, the Apollo Lunar Module is the only lunar module to have ever been used in human spaceflight, completing six lunar landings from 1969 to 1972 during the United States' Apollo program.
The LK lunar module was developed by the Soviet Union in the 1960s as a part of several Soviet crewed lunar programs. Several LK modules were flown without crew in low Earth orbit, but the LK lunar module never flew to the Moon, as the development of the N1 Rocket Launch Vehicle required for the lunar flight suffered setbacks (including several launch failures), and after the first crewed Moon landings were achieved by the United States, the Soviet Union cancelled both the N1 Rocket and the LK Lunar Module programs without any further development.