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The Editors of Encyclopaedia Britannica
LAST UPDATED: Dec 10, 2018 See Article History
Apollo, project conducted by the U.S. National Aeronautics and Space Administration (NASA) in the 1960s and ’70s that landed the first humans on the Moon. In May 1961 Pres. John F. Kennedy committed America to landing astronauts on the Moon by 1970. The choice among competing techniques for achieving a Moon landing and return was not resolved until considerable further study. Three methods were considered. In direct ascent, one vehicle would lift off from Earth, land on the Moon, and return. However, the proposed Nova rocket would not be ready by 1970. In Earth orbit rendezvous, a spacecraft carrying the crew would dock in Earth orbit with the propulsion unit that would carry enough fuel to go to the Moon. However, this method required two separate launches.
In the method ultimately employed, lunar orbit rendezvous, a powerful launch vehicle (Saturn V rocket) placed a 50-ton spacecraft in a lunar trajectory. The spacecraft had three parts. The conical command module (CM) carried three astronauts. The service module (SM) was attached to the back of the CM and carried its fuel and power to form the command/service module (CSM). Docked to the front of the CSM was the lunar module (LM). One astronaut stayed in the CSM while the other two landed on the Moon in the LM. The LM had a descent and ascent stage. The descent stage was left on the Moon, and the astronauts returned to the CSM in the ascent stage, which was discarded in lunar orbit. Before reentering Earth’s atmosphere, the SM was jettisoned to burn up. The CM splashed down in the ocean. The lunar orbit rendezvous had the advantages of requiring only one rocket and of saving fuel and mass since the LM did not need to return to Earth.
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NOVA Published on Dec 29, 2018
(Premiered December 26, 2018) Apollo astronauts and engineers tell the inside story of Apollo 8, the first manned mission to the moon. The U.S. space program suffered a bitter setback when Apollo 1 ended in a deadly fire during a pre-launch run-through. In disarray, and threatened by the prospect of a Soviet Union victory in the space race, NASA decided upon a radical and risky change of plan: turn Apollo 8 from an earth-orbit mission into a daring sprint to the moon while relying on untried new technologies. Fifty years after the historic mission, the Apollo 8 astronauts and engineers recount the feats of engineering that paved the way to the moon.
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