Luna — 1959 – 1976
The Soviet Union conducted both the Luna and Zond lunar exploration programs during the U.S. Apollo program. The Luna program successfully sent 20 spacecraft to the Moon between 1959 and 1976. Among the program highlights, Luna produced the first probe impact on the Moon, first flyby and image of the farside of the Moon, the first lunar orbiter, and the first probe to circle the Moon and return to Earth. The final Luna mission was Luna 24 in 1976, which was the third Luna mission to return samples from the Moon.
Hiten — 1990
This spacecraft, originally known as Muses-A, tested guidance technology using the gravitational assist of the Moon. The spacecraft orbited the Moon in 1990 and returned technological data for use in spacecraft development.
Clementine — 1994
Clementine was the first U.S. mission to return to the Moon after Apollo. Between February and March of 1994, the spacecraft orbited the Moon mapping the lunar surface in greater detail than ever before. The multispectral data returned was used to create minearological maps and laser altimeter data produced the first global topographic map of the Moon. It was the Clementine mission that gave exciting details of a massive south polar crater, re-kindling long-standing debates over possible frozen water in the lunar craters.
Lunar Prospector — 1998
Launched in January of 1998, the Lunar Prospector had a one-year primary mission to orbit the Moon and obtain data to answer many questions about the Moon, including the possible existence of water in polar craters. The spacecraft returned a wealth of data which is still being analyzed. The spacecraft is scheduled to impact with the Moon in July of 1999.
SMART 1 — 2003 – 2006
In September of 2003, the European Space Agency launched the first of its SMART-1 (Small Missions for Advanced Research in Technology-1) missions. It travelled to the Moon using solar-electric propulsion and carrying a battery of miniaturised instruments. SMART-1 did the first comprehensive inventory of key chemical elements in the lunar surface. It also investigated the theory that the Moon was formed following the violent collision of a smaller planet with Earth, four and a half thousand million years ago. In 2006, it was deliberately crashed into the surface of the Moon, ending its mission.
Kaguya (Selene) — 2007 – 2009
The Japan Aerospace Exploration Agency (JAXA) launched "KAGUYA (SELENE)" by the H-IIA Launch Vehicle in September 2007 (JST) from Tanegashima Space Center (TNSC). The major objectives of the "KAGUYA" mission were to obtain scientific data of the lunar origin and evolution and to develop the technology for the future lunar exploration. "KAGUYA" consisted of a main orbiting satellite at about 100km altitude and two small satellites (Relay Satellite and VRAD Satellite) in polar orbit. The orbiters carried instruments for scientific investigation of the Moon, on the Moon, and from the Moon. KAGUYA was impacted to the south-east of near side of the Moon on June 10, 2009 (GMT).
For more information on these and other Moon related resources, see the NASA Moon Page.