Fifty years ago, on July 20, 1969, the world watched in wonder as the first humans landed on the Moon.
Five days earlier, a giant Saturn V rocket lifted off from the Kennedy Space Center in Florida, with the Apollo 11 space vehicle and its three astronauts — Neil Armstrong, commander, Buzz Aldrin, lunar module pilot, and Michael Collins, command module pilot — on board.
And at 4:17 p.m., EDT, Armstrong transmitted the message “Houston, Tranquility Base here. The Eagle has landed,” indicating to the waiting world that the lunar module had safely landed on the Moon.
Collins remained in lunar orbit onboard the command module.
Six hours later, Armstrong became the first human to walk on the Moon, telling the world “That’s one small step for (a) man, one giant leap for mankind.”
Aldrin joined him on the lunar surface 19 mintutes later.
All told, the two spent 21.5 hours on the lunar surface, and about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds of lunar material to bring back to Earth.
Apollo 11 was the fifth crewed mission of NASA’s Apollo program. The Apollo spacecraft had three parts: a command module with a cabin for the three astronauts, and the only part that returned to Earth; a service module, which supported the command module with propulsion, electrical power, oxygen, and water; and a lunar module that had two stages — a descent stage for landing on the Moon, and an ascent stage to place the astronauts back into lunar orbit.
After being sent to the Moon by the Saturn V’s third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit. Armstrong and Aldrin then moved into Eagle and landed in the Sea of Tranquillity. The astronauts used Eagle’s ascent stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that propelled the ship out of the last of its 30 lunar orbits on a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24, after more than eight days in space.