[[Lunar Orbit Rendezvous]] ([[LOR]]) was the mission profile used by [[NASA]]'s [[Apollo program]] to land humans on the Moon. It was a groundbreaking and innovative approach that was chosen over other alternatives like Earth Orbit Rendezvous (EOR) and Direct Ascent. The LOR method involved using two separate spacecraft: the Command Module (CM) and the Lunar Module (LM). The CM would remain in lunar orbit while the LM descended to the Moon's surface with astronauts onboard. After completing their activities on the lunar surface, the astronauts would return to the LM, leaving behind any unnecessary equipment. The ascent stage of the LM would then launch from the Moon's surface and rendezvous with the CM in lunar orbit. There were several advantages to using LOR. First, it required less fuel compared to a Direct Ascent approach, where a single spacecraft would land on and return from the Moon's surface as a whole. This made it easier to launch from Earth and reduced overall mission complexity. Secondly, using separate vehicles allowed for more specialized design and functionality. The LM could be optimized for landing and ascending from the Moon's surface, while the CM could focus on orbital operations and crew accommodation during transit to and from Earth. Additionally, LOR provided a safety net. If something went wrong during descent or ascent, such as an engine failure or other critical issue, there was still a backup vehicle available in lunar orbit for astronauts to return safely to Earth. The success of Lunar Orbit Rendezvous came with Apollo 11 when Neil Armstrong and Buzz Aldrin became the first humans to set foot on the Moon in July 1969. The LOR approach continued throughout subsequent Apollo missions until Apollo 17 in December 1972. Overall, Lunar Orbit Rendezvous was a crucial component of NASA's Apollo program that enabled successful manned lunar landings by efficiently utilizing resources, providing redundancy for crew safety, and allowing for specialized spacecraft design.