Announced to the pubic in August 1965, the Manned Orbiting Laboratory (MOL) was described as a technology-development platform that would aid manned and unmanned space efforts.
The project also had a top-secret mission: MOL was to be the first U.S. manned spy satellite. The program was terminated in 1969, before any operational flights had occurred.
MOL was to be 71.9 feet (21.9 meters) from the nose of its Gemini-B command module to the tail of its spy satellite cargo. The craft was to be 10 feet (3.0 m) in diameter and would have weighed 31,910 lbs. (14,470 kilograms).
The rear section of MOL would have housed a Keyhole-10 spy satellite code-named “Dorian.” This space telescope was designed to be pointed down at Earth, not out toward the stars. Mission planners hoped to use MOL’s 72-inch (1.8 m) optical mirror to capture high-resolution images of the Soviet Union from a polar orbit of Earth.
Source SPACE.com: All about our solar system, outer space and exploration.
Source: http://www.space.com/31433-secrets-of-the-manned-orbiting-laboratory-revealed-infographic.html
