Apollo 12, the second manned mission to land on the Moon, was planned and executed as a precision landing. The astronauts landed the Lunar Module within walking distance of the Surveyor III spacecraft which had landed on the Moon in April of 1967. The astronauts brought instruments from Surveyor III back to Earth to examine the effects of long-term exposure to the lunar environment.
Primary objectives included:
Secondary objective was to the retrieve portions of the Surveyor III spacecraft which had been exposed to the lunar environment since the unmanned spacecraft soft-landed on the inner slope of a crater on April 20, 1967.
The Apollo 12 mission was the second manned lunar landing mission. Its objective was to perform detailed scientific lunar exploration. The space vehicle with a crew of Charles (Pete) Conrad, Jr., the commander; Richard F. Gordon, the command module pilot; and Alan L. Bean, the lunar module pilot, was launched from Kennedy Space Center, Fla., at 11:22:00 EST on November 14, 1969.
A precision landing was made using automatic guidance, with only small manual corrections required in the final phases of descent. Touchdown occured at 110.5 hr ground elapsed time (GET), at a point only 600 feet (183 meters) from the target point, the Surveyor III spacecraft. The landing was in the Ocean of Storms.
This precision landing was of great significance to the future lunar exploration program, because landing points in rough terrain of great scientific interest could now be targeted.
The first of two planned extravehicular activiy (EVA) periods began at 115 hr GET. A color television camera mounted on the descent stage provided live television coverage of the descent of both astronauts to the lunar surface. Television coverage was subsequently lost because of the inadvertent pointing of the camera at the Sun.
The crew emplaced the U.S. flag and the solar-wind composition experiment. They collected lunar samples and core-tube specimens during this first EVA period which lasted approximately four hours.
Following a seven-hour rest period, the second EVA period began at 131.5 hr GET. The two astronauts started a geology traverse. The traverse covered approximately 4300 feet (1311 meters) and lasted 3 hours and 50 minutes. During the traverse, documented samples, core-tube samples, trench site samples, and gas analysis samples were collected. The Apollo 12 samples were mostly basalts, dark-colored igneous rocks, and they were hundreds of millions of years younger than the rocks collected on Apollo 11.
The crew photographed Surveyor III, which landed on the lunar surface in April 1967, and retrieved a painted tube, an unpainted tube, the Surveyor III scoop and the television camera. The television camera is now on display in the National Air and Space Museum's "Exploring The Planets" gallery.
Another rest period and a final checkout preceded the liftoff of the lunar module ascent stage at 142 hr GET. Following crew transfer, the ascent stage was remotely guided to impact on the lunar surface to provide an active seismic source for the passive seismic experiment that had been emplaced. The command module landed in the Pacific Ocean at 244.5 hr GET.
From NASA SP-235, Apollo 12 Preliminary Science Report.