American astronaut Neil Armstrong was the first person to set foot on the Moon. Armstrong, along with two other American astronauts, Buzz Aldrin and Michael Collins, was launched towards the Moon on July 16, 1969, as part of the Apollo 11 mission.
On July 20, 1969, Armstrong, who was the mission commander, and Buzz Aldrin, the lunar module pilot, landed the Apollo Lunar Module Eagle on the Moon.
The mission was "one small step for a man, one giant leap for mankind". To commemorate the anniversary of the first landing on the lunar surface by humans, International Moon Day is observed worldwide on July 20.
A total of 12 humans have walked on the Moon so far. The missions which carried humans to the lunar surface are Apollo 11, Apollo 12, Apollo 14, Apollo 15, Apollo 16 and Apollo 17. The last time humans travelled to the Moon was in 1972.
NASA's Artemis Project, the first human mission to the Moon since 1972, aims to carry the first woman, and the first person of colour to the lunar surface, by 2024.
Here is the list of all the missions as part of which humans walked on the Moon.
Apollo 11
The Apollo 11 mission was the first crewed landing on the Moon. Three astronauts were launched towards the Moon atop a Saturn V rocket. Armstrong, Aldrin and Collins deployed instruments on the Moon, captured photographs, and collected samples.
In an address at Rice University on September 12, 1962, then United States President John F Kennedy had informed the public about his goal to land a man on the Moon before 1970. "We choose to go to the Moon," he had said. In less than a decade, the Apollo 11 mission was launched, sending the first humans to the Moon.
Apollo 12
The Apollo 12 mission launched astronauts Charles "Pete" Conrad Jr, Apan Bean, and Richard F Gordon Jr towards the Moon on November 14, 1969. The astronauts blasted off towards the Moon atop a Saturn V rocket.
Just after launch, the Apollo 12 spacecraft was struck twice by lightning. Though this temporarily knocked out electrical power, the problems did not stop a successful mission.
The goals of Apollo 12 included investigation of the lunar surface environment, and enhancement of the capability for human lunar exploration.
The Apollo 12 crew deployed an instrument package and collected more than 34 kilograms of samples, captured photographs of the lunar surface, collected samples of the solar wind, and investigated soil mechanics.
They also retrieved parts of the robotic Surveyor 3 spacecraft that had previously landed on the lunar surface.
The crew performed extravehicular activities (EVA) totalling nearly eight hours, and remained on the lunar surface for more than 31 hours.
Apollo 12 marked the first time human explorers met up with a robotic spacecraft in space, and was also the first crewed lunar mission with science as the primary objective.
Apollo 14
Astronauts Alan B Shepard Jr, Stuart A Roosa, and Edgar D Mitchell were launched towards the Moon as part of the Apollo 14 mission on January 31, 1971.
This was the first flight to the Moon after the Apollo 13 mission was aborted.
The Apollo 14 crew carried out the longest list of experiments on the Moon and in lunar orbit as of that time. The astronauts demonstrated that reasonably long distances can be traversed on foot on the Moon.
The crew brought back almost 43 kilograms of lunar samples to Earth.
It was the third mission in which humans landed on the Moon, and was commanded by Alan B Shepard Jr, the man who became the first American in space, on May 5, 1961. He piloted the Mercury spacecraft Freedom 7 on a 490-kilometre, 15-minute suborbital flight.
Stuart A Roosa piloted the command module "Kitty Hawk". The lunar module "Antares" was piloted by Edgar D Mitchell. Apollo 14 was the first space mission for Roosa and Mitchell.
Apollo 15
Astronauts David R Scott, James B Irwin, and Alfred M Worden were the crew members of Apollo 15, the fourth mission in which humans walked on the Moon. Apollo 15 marked the first time humans drove on the Moon.
The astronauts were launched towards the Moon on July 26, 1971.
Apollo 15 doubled the time spent on the lunar surface, compared to the previous record-holder, Apollo 14.
The goals of Apollo 15 included exploring the mountainous Hadley-Apennine region, making engineering evaluations of new Apollo equipment, activating lunar surface scientific experiments, photography, and conducting experiments related to lunar orbit.
The Apollo 15 astronauts, with the help of the first automotive vehicle designed for off-planet use, explored a more diverse region of the Moon than ever before.
Apollo 16
Astronauts John W Young, Charles M Duke Jr, and Thomas K Mattingly were launched towards the Moon on April 16, 1972, as part of the Apollo 16 mission. At that time, scientists believed that lunar highlands were of volcanic origin. The findings of Apollo 16 proved these assumptions wrong.
Apollo 16 was the first crewed landing in the central lunar highlands. Astronauts made the first spacewalk during the return journey to Earth, as part of Apollo 16.
Though Apollo 16 was the fifth mission in which astronauts walked on the surface of the Moon, it was far from routine. This is because it changed the way scientists think of the Moon.
John W Young, the commander of the mission, and Charles M Duke, pilot of the lunar module "Orion", landed at the western edge of the Descartes mountains on the Moon, on April 21, 1972.
The command module "Casper" was piloted by Thomas K Mattingly, who also performed experiments in lunar orbit.
The destination for Apollo 16 was different from those for the previous Apollo missions. Three of the destinations were in mare regions, which are flat, dark plains of lower elevation on the Moon, also referred to as lunar seas.
The measurements made and samples collected by Apollo 16 astronauts disproved the hypothesis that the central lunar highlands on the lunar surface were a product of volcanic eruptions in the Moon's ancient past.
Apollo 17
Apollo 17 was the last time humans landed on the Moon. Astronauts Eugene A Cernan, Ronald E Evans, and Harrison H Schmitt were launched towards the Moon on December 7, 1972, atop a Saturn V rocket, as part of the Apollo 17 mission. The crew reached the lunar surface on December 11, 1972.
The astronauts collected the oldest known unshocked lunar rock. This suggests that the Moon had a dynamo-generated magnetic field in its past. This is a magnetic field generated by a fluid inside an astronomical object.
The crew collected samples of "orange soil" containing volcanic glass, and deployed scientific experiments.
They left a plaque on the Moon which reads: "Here man completed his first exploration of the Moon, December 1972 A.D. May the spirit of peace in which he came be reflected in the lives of all mankind".
Apollo 17 was the first mission in which a scientist got the opportunity to investigate the Moon firsthand.
Harrison H Schmitt was a geologist and had been part of the backup crew for Apollo 15. He served as pilot of the lunar module, "Challenger", for Apollo 17.
The command module, "America", was piloted by Ronald E Evans. Eugene A Cernan was the commander of Apollo 17.
Artemis Program
The Artemis project, the first human mission to the Moon since 1972, aims to carry the first woman, and the first person of colour to the lunar surface, by 2024.
The first spaceflight that landed humans on the lunar surface was Apollo 11 on July 20, 1969, and the last one was Apollo 17 on December 11, 1972.
Artemis, the Goddess of the Moon in Greek Mythology after whom this project has been named, was the twin sister of Apollo.
The objective behind the Artemis Mission is that it will enable NASA to demonstrate new technologies on the Moon, which will pave the way for future exploration of Mars, the space agency has said.
The mission has three stages, Artemis I, II and III. NASA's contract with SpaceX is for Artemis III.
NASA's massive Space Launch System Rocket and Orion Space Capsule will carry astronauts into lunar orbit. From there, SpaceX’s Human Lander System (HLS) will ferry the astronauts to the Moon's icy south pole, the space agency said on its website.
Artemis I will be an uncrewed test flight. Orion will be carried atop the super-heavy lift rocket, Space Launch System (SLS), without any human in the capsule. If Artemis I is successful, it will be certified that the SLS and Orion can be used for the other two Artemis missions, which will be crewed flights.
Artemis II, the first crewed flight of this programme, will send four astronauts for a lunar flyby test in the Orion capsule, for a maximum of 21 days, at the end of which the crew will be brought back to Earth.
In Artemis III, the Orion capsule will connect to SpaceX's HLS for the final leg to the lunar south pole, on which humans will set foot for the first time.