This is a timeline of Solar System exploration ordering events in the exploration of the Solar System by date of spacecraft launch. It includes:
Luna 11 was an uncrewed space mission of the Soviet Union's Luna program. It was also called Lunik 11. Luna 11 was launched towards the Moon from an Earth-orbiting platform and entered lunar orbit on 27 August 1966.
Luna 16 was an uncrewed space mission, part of the Soviet Luna program. It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth. The 101 grams sample was returned from Mare Fecunditatis. It represented the first successful lunar sample return mission by the Soviet Union and was the third lunar sample return mission overall.
Luna 20 was the second of three successful Soviet lunar sample return missions. It was flown as part of the Luna program as a robotic competitor to the six successful Apollo lunar sample return missions.
A lander is a spacecraft that descends towards, comes to rest on, the surface of an astronomical body. In contrast to an impact probe, which makes a hard landing that damages or destroys the probe upon reaching the surface, a lander makes a soft landing after which the probe remains functional.
The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately 6.5 miles (10.5 km) northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC employs approximately 10,000 civil servants and contractors. Named in recognition of American rocket propulsion pioneer Robert H. Goddard, it is one of ten major NASA field centers. GSFC is partially within the former Goddard census-designated place; it has a Greenbelt mailing address.
The Discovery Program is a series of Solar System exploration missions funded by the US National Aeronautics and Space Administration (NASA) through its Planetary Missions Program Office. The cost of each mission is capped at a lower level than missions from NASA's New Frontiers or Flagship Programs. As a result, Discovery missions tend to be more focused on a specific scientific goal rather than serving a general purpose.
A Moon landing is the arrival of a spacecraft on the surface of the Moon. This includes both crewed and robotic missions. The first human-made object to touch the Moon was the Soviet Union's Luna 2, on 13 September 1959.
Lunar water is water that is present on the Moon. Diffuse water molecules can persist at the Moon's sunlit surface, as discovered by NASA's SOFIA observatory in 2020. Gradually water vapor is decomposed by sunlight, leaving hydrogen and oxygen lost to outer space. Scientists have found water ice in the cold, permanently shadowed craters at the Moon's poles. Water molecules are also present in the extremely thin lunar atmosphere.
The physical exploration of the Moon began when Luna 2, a space probe launched by the Soviet Union, made an impact on the surface of the Moon on September 14, 1959. Prior to that the only available means of exploration had been observation from Earth. The invention of the optical telescope brought about the first leap in the quality of lunar observations. Galileo Galilei is generally credited as the first person to use a telescope for astronomical purposes; having made his own telescope in 1609, the mountains and craters on the lunar surface were among his first observations using it.
The Lunar Crater Observation and Sensing Satellite (LCROSS) was a robotic spacecraft operated by NASA. The mission was conceived as a low-cost means of determining the nature of hydrogen detected at the polar regions of the Moon. Launched immediately after discovery of lunar water by Chandrayaan-1, the main LCROSS mission objective was to further explore the presence of water in the form of ice in a permanently shadowed crater near a lunar polar region. It was successful in confirming water in the southern lunar crater Cabeus.
Miniature inertial measurement unit (MIMU) is an inertial measurement unit (IMU) developed and built by Honeywell International to control and stabilize spacecraft during mission operations. MIMUs can also be configured to perform as an inertial reference unit (IRU). MIMUs have been flown on GEO, Low Earth orbit (LEO), planetary missions and deep-space-probe applications.
The Lunar Atmosphere and Dust Environment Explorer was a NASA lunar exploration and technology demonstration mission. It was launched on a Minotaur V rocket from the Mid-Atlantic Regional Spaceport on September 7, 2013. During its seven-month mission, LADEE orbited around the Moon's equator, using its instruments to study the lunar exosphere and dust in the Moon's vicinity. Instruments included a dust detector, neutral mass spectrometer, and ultraviolet-visible spectrometer, as well as a technology demonstration consisting of a laser communications terminal. The mission ended on April 18, 2014, when the spacecraft's controllers intentionally crashed LADEE into the far side of the Moon, which, later, was determined to be near the eastern rim of Sundman V crater.
The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic missions to the Moon. Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies.
The lunar south pole is the southernmost point on the Moon, at 90°S. It is of special interest to scientists because of the occurrence of water ice in permanently shadowed areas around it. The lunar south pole region features craters that are unique in that the near-constant sunlight does not reach their interior. Such craters are cold traps that contain a fossil record of hydrogen, water ice, and other volatiles dating from the early Solar System. In contrast, the lunar north pole region exhibits a much lower quantity of similarly sheltered craters.
Lunar IceCube is a NASA nanosatellite orbiter mission to prospect, locate, and estimate amount and composition of water ice deposits on the Moon for future exploitation by robots or humans. It was launched as a secondary payload mission on Artemis 1, the first flight of the Space Launch System (SLS), on 16 November 2022.
Lunar Trailblazer is a planned small lunar orbiter, part of NASA's SIMPLEx program, that will detect and map water on the lunar surface to determine how its form, abundance, and location relate to geology. Its mission is to aid in the understanding of lunar water and the Moon's water cycle. Lunar Trailblazer is currently slated to launch in 2023 as a secondary payload on the IM-2 mission, with the satellite scheduled to be completed in early 2023. The Principal Investigator (PI) of the mission is Bethany Ehlmann, a professor at Caltech.
