Lunar orbit rendezvous (LOR) is a process for landing humans on the Moon and returning them to Earth. It was utilized for the Apollo program missions in the 1960s and 1970s. In a LOR mission, a main spacecraft and a lunar lander travel to lunar orbit. The lunar lander then independently descends to the surface of the Moon, while the main spacecraft remains in lunar orbit. After completion of the mission there, the lander returns to lunar orbit to rendezvous and re-dock with the main spacecraft, then is discarded after transfer of crew and payload. Only the main spacecraft returns to Earth.
Lunar orbit rendezvous was first proposed in 1919 by Ukrainian engineer Yuri Kondratyuk, as the most economical way of sending a human on a round-trip journey to the Moon.
Robert Laurel "Bob" Crippen (born September 11, 1937), (
Capt,
USN, Ret.), is a retired
American naval officer and
aviator,
test pilot,
aerospace engineer, and former
astronaut for the
United States Department of Defense and for
NASA.
An aviator with the U.S. Navy, Crippen was originally chosen to the U.S. Air Force's Manned Orbiting Laboratory program, a project involving a military space station, in 1966. When that project was canceled in 1969, Crippen was transferred to NASA. He was selected as pilot of the first Space Shuttle mission, STS-1, along with commander John Young, which he flew on April 12-14, 1981, on the orbiter Columbia.
Crippen would likewise become the first Shuttle pilot to be promoted to commander, leading the STS-7 mission on orbiter Challenger in June 1983. He would command two other missions (STS-41-C and STS-41-G) in 1984. He was training for another mission when the Challenger disaster occurred, and was re-assigned as Deputy Director of Kennedy Space Center in 1987.
Crippen would serve as the Director of Kennedy Space Center from January 1992 until January 1995, when he left NASA. He would hold executive positions at Lockheed Martin and Thiokol before retiring in 2001.