This is a list of robotic space probes that have flown by, impacted, orbited or landed on the Moon for the purpose of lunar exploration, as well as probes launched toward the Moon that failed to reach their target.. The second of two Nasa moon probes successfully completed its main engine burn and arrived in orbit over the moon last night. The probes intentionally were sent into the lunar surface because they did not have sufficient altitude or fuel to continue science operations. “Even during the last half of their last orbit, we are going to do an engineering experiment that could help future missions operate more efficiently.” Map of lunar heritage sites along with flight path of GRAIL probes to their final resting place on an unnamed mountain on the Moon’s north pole (Credits: NASA). Their successful prime and extended science missions generated the highest resolution gravity field map of any celestial body. Some researchers say so. The Pioneer program was a series of exploration probes launched between 1958 and 1978. • End of GRAIL mission on Dec. 17, 2012: On December 14, 2012, the twin probes, Ebb and Flow, comprising NASA's GRAIL mission, were commanded to descend into a lower orbit and target a mountain near the moon's north pole for impact. Pioneer probes conducted various missions, including some of the first lunar probes, investigations of conditions in interplanetary space, exploration of the planet Venus, as … Cassini carried a passenger to the Saturn system, the European Huygens probe —the first human-made object to land on a world in the distant outer solar system.. After 20 years in space — 13 of those years exploring Saturn — Cassini exhausted its fuel supply. NASA's GRAIL mission, due to launch on Sept. 8th, could help confirm or refute the "two moon" hypothesis. Dec. 18, 2012: NASA has named the site where twin gravity probes hit the Moon yesterday in honor of the late astronaut, Sally K. Ride, who was America's first woman in space and a member of the probes' mission team. Cassini revealed in great detail the true wonders of Saturn, a giant world ruled by raging storms and delicate harmonies of gravity. The Grail-B spacecraft reunited with Grail-A … The crewed Apollo missions are listed at List of missions to the Moon Moreover, the missing satellite might still be up there--splattered against the far side of the Moon. These folks, not NASA, are the reason this nation has not returned to the moon. Did our planet once have two moons? Image: The United States Capitol, meeting place of the Congress of the United States. Pioneer.