Apollo 11, U.S. spaceflight during which commander Neil Armstrong and lunar module pilot Edwin (“Buzz”) Aldrin, Jr., on July 20, 1969, became the first people to land on the Moon and walk the lunar surface. Apollo 11 was the culmination of the Apollo program and a massive national commitment by the United States to beat the Soviet Union in putting people on the Moon.
From the time of its launch on July 16, 1969, until the return splashdown on July 24, almost every major aspect of the flight of Apollo 11 was witnessed via television by hundreds of millions of people in nearly every part of the globe. The pulse of humanity rose with the giant, 111-metre- (363-foot-) high, 3,038,500-kg (6,698,700-pound) Saturn V launch vehicle as it made its flawless flight from Pad 39A at Cape Kennedy (now Cape Canaveral), Florida, before hundreds of thousands of spectators. So accurate was the translunar insertion that three of the en route trajectory corrections planned were not necessary. Aboard Apollo 11 were Armstrong, Aldrin, and command module pilot Michael Collins. Their enthusiasm was evident from the beginning, as Armstrong exclaimed, “This Saturn gave us a magnificent ride.…It was beautiful!”
This Saturn gave us a magnificent ride.…It was beautiful!
The third stage of the Saturn then fired to start the crew on their 376,400-km (234,000-mile) journey to the Moon. The three astronauts conducted their transposition and docking maneuvers, first turning the command module, Columbia, and its attached service module around and then extracting the lunar module from its resting place above the Saturn’s third stage. On their arrival the astronauts slowed the spacecraft so that it would go into lunar orbit. Apollo 11 entered first an elliptical orbit 114 by 313 km (71 by 194 miles) and then a nearly circular orbit between 100 and 122 km (62 and 76 miles) above the surface of the Moon.
On the morning of July 20, Armstrong and Aldrin crawled from the command module through an interconnecting tunnel into the lunar module, Eagle. Toward the end of the 12th lunar orbit, the Apollo 11 spacecraft became two separate spacecraft: Columbia, piloted by Collins, and Eagle, occupied by Armstrong and Aldrin.
By firing Eagle’s propulsion system, the two astronauts changed from their nearly circular orbit to an elliptical course whose closest approach to the Moon was only 15,000 metres (50,000 feet). At this low point they again fired their engine, this time to undergo the powered descent initiation manoeuvre. Five times during the descent, the guidance computer triggered an alarm (called “1202” or “1201”) that its memory was full, but NASA simulations before the mission showed that a landing could still happen despite the alarm, and thus Mission Control told the astronauts to continue the descent. At about 150 metres (500 feet) above the surface, Armstrong began manoeuvring the craft manually (although the main engine continued under automatic control) to avoid landing in a rock-strewn crater.