Аполлон-11 қонған жер: Айдың Ырысқан даласы

Landing site of Apollo 11 on the Moon

Tranquility Base (Statio Tranquillitatis) is the site on the Moon where, in July 1969, humans landed and walked on a celestial body other than Earth for the first time. On July 20, 1969, Apollo 11 crewmembers Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module Eagle at approximately 20:17:40 UTC. Armstrong exited the spacecraft six hours and 39 minutes after touchdown, followed 19 minutes later by Aldrin. The astronauts spent two hours and 31 minutes examining and photographing the lunar surface, setting up several scientific experiment packages, and collecting of dirt and rock samples for return to Earth. They lifted off the surface on July 21 at 17:54 UTC. Tranquility Base was named by Aldrin and Armstrong, and first announced by Armstrong when the Lunar Module Eagle landed. It is located in the south western corner of the dark lunar plain Mare Tranquillitatis ("Sea of Tranquility"). The U. S. states of California and New Mexico have registered Tranquility Base as a heritage site associated with them, but Texas, the U. S. National Park Service, and UNESCO have declined to do so, due to the technicality that it is not located within their borders.

For more than two years, NASA planners considered a collection of 30 potential sites for the first crewed landing. Based on high resolution photographs taken by the Lunar Orbiter spacecraft, and photos and data taken by the uncrewed Surveyor landers, this list was narrowed down to five sites located near the lunar equator. They ranged between 45 degrees east and west, and 5 degrees north and south of the center of the Moon's facing side. They were numbered 1 to 5, going from east to west. Site number 2, centered at , was the Sea of Tranquility site ultimately chosen. Since a precision landing was not expected on the first mission, the target area was an ellipse measuring 11.5 mile (19 km) east and west by 3.0 mile (5 km) north and south. On the landing, a combination of thrust from residual pressure in the docking tunnel that connected the Lunar Module with the command module Columbia in orbit, and an imperfect understanding of the Moon's uneven gravitational field, resulted in navigation errors which pushed the powered descent initiation point about 3 mile (5 km), and thus the computer targeted landing spot about 4 mile (6 km), downrange (west) of the planned target. The automated targeting system was taking Eagle toward what Armstrong described as a "football field sized crater, with a large number of big boulders and rocks for about one or two crater diameters around it", which he avoided by assuming manual control and flying a bit farther downrange. The landing was still within the target ellipse.