Lunar Probes - History Before 1991
The first NASA lunar probes were the NASA Ranger series between 1961 and 1965, which were all designed to impact the Moon and take high resolution images shortly before these impacts, e.g., 0.5 meters resolution. The first six failed but the last three were successful.
The next generation of spacecraft were soft landers, the Lunar Surveyor series. Surveyor 1 soft-landed in June, 1966. There were seven Surveyors, though two failed (one engine failed to ignite, another just lost communication shortly before landing). The last was in January 1968. The Surveyors took detailed photos of candidate Apollo landing sites, tested the surface with a scoop, and had an alpha scattering instrument for chemical analysis of the lunar soil.
In 1966 to 1967, NASA mapped 99% of the lunar surface with its five successful probes Lunar Orbiter 1 through Lunar Orbiter 5, achieving a resolution of 60 meters or better. Lunar Orbiter 5 mapped 36 preselected candidate Apollo sites to between 20 meter and 2 meter resolution.
Apollos 8 and 10 were the first manned missions to orbit the Moon in 1968 and 1969 and returned pictures. Apollos 11, 12, 14, 15, 16 and 17 were manned missions which landed on the Moon between 1969 and 1972, returning almost 400 kilograms (900 pounds) of lunar samples and data from various other experiments.
Russian probes were the first and the last to visit the Moon in the 1959-1976 era. Soviet Luna and Zond missions also photographed the Moon, with Luna 3 giving humanity the first view of the lunar farside in 1959. There were a total of 24 Luna missions, with the early missions being photographic orbiters and the latter being landers. The Luna 13 robotic probe successfully soft landed on the Moon in February, 1966, beating the American soft-lander probe by four months, and providing detailed pictures of the Moon's surface. Luna 16 in 1970 was the first of three Soviet probes to returned a lunar sample (after Apollo 11). Some of the Luna probes also had robotic rovers to drive around the lunar surface, called Lunokhod. The five Zond spacecraft were of a different design and operated concurrently between 1965 and 1970, all photographic orbiters, while the Luna missions started focusing on landing on the Moon. The Luna 24 mission was the last mission to the Moon in 1976, a sample return mission.
After 1976, the Moon was ignored by space probes until 1990, and not revisited in earnest until 1994.
The NASA probe Galileo, headed for Jupiter, turned on some of its equipment during two brief flybys of the Moon in 1990 and 1992 during gravity assist maneuvers as a result of its shoestring launch vehicle budget. However, the amount of data acquired was small and very general in nature.
The first return to the Moon mission was by the U.S. Department of Defense's new Strategic Defense Initiative Organization (SDIO, aka "Star Wars"), which flew the Clementine 1 probe to map the Moon's surface with modern instruments, in conjunction with NASA. Clementine 1 arrived at the Moon in February 1994, and is discussed in the section linked below. Clementine was the first probe to discover water ice at the lunar poles.
As a result of Clementine 1's discovery of ice on the Moon, interest in the Moon dramatically increased and political pressure resulted in NASA funding its first probe to the Moon in more than 20 years, the Lunar Prospector. Unfortunately, funding for Clementine 2, a Department of Defense mission to several asteroids near Earth, was vetoed by President Clinton (line item veto) after it successfully passed funding by a more enlightened Congress. However, funding for the Lunar Prospector probe passed both Congress and the President.
This helped renew interest in the Moon by NASA and other countries.
After Clementine 1 came NASA's Lunar Prospector, which in 1998 confirmed the presence of water in the lunar poles, as well as mapped the Moon in much finer detail.
After Lunar Prospector came NASA's Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observations and Sensing Satellite (LCROSS), which in 2009 started to further map the Moon, and also crashed a rocket stage into a crater in order to measure the concentration of water in the plume.
The following sections cover only government funded probes. No private sector probes have been sent to the Moon nor received a firm financial commitment and schedule to date, though this may change soon. The private sector probes will be put into the Missions section instead of this Lunar section since the emphasis there is business and sustainability (though they may be moved here later if and when a financial commitment and reasonably firm schedule are achieved).
Additional, children pages of this current parent page:
Probes, History and Future :