Apollo 10 was the fourth human spaceflight in the United States' Apollo program and the second to orbit the Moon. NASA, the mission's operator, described it as a "dress rehearsal" for the first Moon landing. It was designated an "F" mission, intended to test all spacecraft components and procedures short of actual descent and landing.
This is a timeline of Solar System exploration ordering events in the exploration of the Solar System by date of spacecraft launch. It includes:
A trans-lunar injection (TLI) is a propulsive maneuver, which is used to send a spacecraft to the Moon. Typical lunar transfer trajectories approximate Hohmann transfers, although low-energy transfers have also been used in some cases, as with the Hiten probe. For short duration missions without significant perturbations from sources outside the Earth-Moon system, a fast Hohmann transfer is typically more practical.
Oceanus Procellarum is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Procellarum is the largest of the maria ("seas"), stretching more than 2,500 km (1,600 mi) across its north–south axis and covering roughly 4,000,000 km2 (1,500,000 sq mi), accounting for 10.5% of the total lunar surface area.
Luna 15 was a robotic space mission of the Soviet Luna programme, that was in lunar orbit together with the Apollo 11 Command module Columbia.
Luna 16 was an uncrewed 1970 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.
Luna 24 was a robotic probe of the Soviet Union's Luna programme. The 24th mission of the Luna series of spacecraft, the mission of the Luna 24 probe was the third Soviet mission to return lunar soil samples from the Moon. The probe landed in Mare Crisium. The mission returned 170.1 g (6.00 oz) of lunar samples to the Earth on 22 August 1976.
A lander is a spacecraft that descends towards, then comes to rest on the surface of an astronomical body other than Earth. 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.
A Moon landing or lunar landing is the arrival of a spacecraft on the surface of the Moon, including both crewed and robotic missions. The first human-made object to touch the Moon was Luna 2 in 1959.
A lunar lander or Moon lander is a spacecraft designed to land on the surface of the Moon. As of 2023, the Apollo Lunar Module is the only lunar lander to have ever been used in human spaceflight, completing six lunar landings from 1969 to 1972 during the United States' Apollo Program. Several robotic landers have reached the surface, and some have returned samples to Earth.
A sample-return mission is a spacecraft mission to collect and return samples from an extraterrestrial location to Earth for analysis. Sample-return missions may bring back merely atoms and molecules or a deposit of complex compounds such as loose material and rocks. These samples may be obtained in a number of ways, such as soil and rock excavation or a collector array used for capturing particles of solar wind or cometary debris. Nonetheless, concerns have been raised that the return of such samples to planet Earth may endanger Earth itself.
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.
Third-party evidence for Apollo Moon landings is evidence, or analysis of evidence, about the Moon landings that does not come from either NASA or the U.S. government, or the Apollo Moon landing hoax theorists. This evidence provides independent confirmation of NASA's account of the six Apollo program Moon missions flown between 1969 and 1972.
A trans-Earth injection (TEI) is a propulsion maneuver used to set a spacecraft on a trajectory which will intersect the Earth's sphere of influence, usually putting the spacecraft on a free return trajectory.
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 following outline is provided as an overview of and topical guide to the Moon:
