Apollo 11 (July 16–24, 1969) was the spaceflight that first landed humans on the Moon. Commander Neil Armstrong

and lunar module pilot Buzz Aldrin formed the American crew that landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC (14:17 CST). 

Armstrong became the first person to step onto the lunar surface six hours and 39 minutes later on July 21 at 02:56 UTC; Aldrin joined him 19 minutes later. 

They spent about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds (21.5 kg) of lunar material to bring back to Earth.

 Command module pilot Michael Collins flew the Command Module Columbia alone in lunar orbit while they were on the Moon's surface. 

Armstrong and Aldrin spent 21 hours, 36 minutes on the lunar surface, at a site they had named Tranquility Base upon landing, before lifting off to rejoin Columbia in lunar orbit.

Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center on Merritt Island, Florida, on July 16 at 13:32 UTC, and it was the fifth crewed mission of 

NASA's Apollo program. The Apollo spacecraft had three parts: a command module (CM) with a cabin for the three astronauts, the only 

part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, and water; 

and a lunar module (LM) 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 Tranquility on July 20. 

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 Columbia out of the last of its 30 lunar orbits onto a trajectory back to Earth.[6] They returned to Earth and 

splashed down in the Pacific Ocean on July 24 after more than eight days in space.

Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience. 

He described the event as "one small step for [a] man, one giant leap for mankind."[a][12] Apollo 11 effectively proved US victory in the Space Race 

to demonstrate spaceflight superiority, by fulfilling a national goal proposed in 1961 by President John F. Kennedy, "before this decade is out, of landing a man on the Moon 

and returning him safely to the Earth."[13]

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In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union.[14]

 On October 4, 1957, the Soviet Union launched Sputnik 1, the first artificial satellite. This surprise success fired fears and imaginations around the world. 

It demonstrated that the Soviet Union had the capability to deliver nuclear weapons over intercontinental distances, and challenged American claims of military, economic and

 technological superiority.[15] This precipitated the Sputnik crisis, and triggered the Space Race to prove which superpower would achieve superior spaceflight capability.[

 President Dwight D. Eisenhower responded to the Sputnik challenge by creating the National Aeronautics and Space Administration (NASA), and initiating Project Mercury, 

which aimed to launch a man into Earth orbit.

But on April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person in space, and the first to orbit the Earth.[19] Nearly a month later, on May 5, 1961, 

Alan Shepard became the first American in space, completing a 15-minute suborbital journey. After being recovered from the Atlantic Ocean, he received a congratulatory 

telephone call from Eisenhower's successor, John F. Kennedy.[20]

Since the Soviet Union had higher lift capacity launch vehicles, Kennedy chose, from among options presented by NASA, 

a challenge beyond the capacity of the existing generation of rocketry, so that the US and Soviet Union would be starting from a position of equality. A crewed mission to the Moon

 would serve this purpose.[21]

On May 25, 1961, Kennedy addressed the United States Congress on "Urgent National Needs" and declared:

I believe that this nation should commit itself to achieving the goal, before this decade [1960s] is out, of landing a man on the Moon and returning him safely to the Earth. 

No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive 

to accomplish. We propose to accelerate the development of the appropriate lunar space craft. We propose to develop alternate liquid and solid fuel boosters, 

much larger than any 

now being developed, until certain which is superior. We propose additional funds for other engine development and for unmanned explorations—explorations which are 

particularly important for one purpose which this nation will never overlook: the survival of the man who first makes this daring flight. But in a very real sense, it will not be 

one man going to the Moon—if we make this judgment affirmatively, it will be an entire nation. For all of us must work to put him there.

— Kennedy's speech to Congress[22]

On September 12, 1962, Kennedy delivered another speech before a crowd of about 40,000 people in the Rice University football stadium in Houston, Texas.

 A widely quoted refrain from the middle portion of the speech reads as follows:

Kennedy, in a blue suit and tie, speaks at a wooden podium bearing the seal of the President of the United States. Vice President Lyndon Johnson and other dignitaries 

stand behind him.

President John F. Kennedy speaking at Rice University on September 12, 1962

There is no strife, no prejudice, no national conflict in outer space as yet. Its hazards are hostile to us all. Its conquest deserves the best of all mankind, and its opportunity 

for peaceful cooperation may never come again. But why, some say, the Moon? Why choose this as our goal? And they may well ask, why climb the highest mountain? 

Why, 35 years ago, fly the Atlantic? Why does Rice play Texas? We choose to go to the Moon! We choose to go to the Moon ... We choose to go to the Moon in this decade 

and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, 

because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too.[25]

In spite of that, the proposed program faced the opposition of many Americans and was dubbed a "moondoggle" by Norbert Wiener, a mathematician at the 

Massachusetts Institute of Technology.[26][27] The effort to land a man on the Moon already had a name: Project Apollo.[28] When Kennedy met with

 Nikita Khrushchev, the Premier of the Soviet Union in June 1961, he proposed making the Moon landing a joint project, but Khrushchev did not take up the offer.[

Kennedy again proposed a joint expedition to the Moon in a speech to the United Nations General Assembly on September 20, 1963.[

 The idea of a joint Moon mission was abandoned after Kennedy's death.[31]

An early and crucial decision was choosing lunar orbit rendezvous over both direct ascent and Earth orbit rendezvous. 

A space rendezvous is an orbital maneuver in which two spacecraft navigate through space and meet up. In July 1962 NASA head James Webb

 announced that lunar orbit rendezvous would be used[32][33] and that the Apollo spacecraft would have three major parts: a command module (CM) with a cabin 

for the three astronauts, and the only part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, 

and water; and a lunar module (LM) that had two stages—a descent stage for landing on the Moon, and an ascent stage to place the astronauts back into lunar orbit.[34] 

This design meant the spacecraft could be launched by a single Saturn V rocket that was then under development.[35]

Technologies and techniques required for Apollo were developed by Project Gemini.[36] The Apollo project was enabled by NASA's adoption of new advances 

in semiconductor electronic technology, including metal-oxide-semiconductor field-effect transistors (MOSFETs) in the Interplanetary Monitoring Platform (IMP)

and silicon integrated circuit (IC) chips in the Apollo Guidance Computer (AGC).[39]

Project Apollo was abruptly halted by the Apollo 1 fire on January 27, 1967, in which astronauts Gus Grissom, Ed White, and Roger B. Chaffee died, 

and the subsequent investigation.[40] In October 1968, Apollo 7 evaluated the command module in Earth orbit,[41] and in December Apollo 8 tested it in lunar orbit. 

In March 1969, Apollo 9 put the lunar module through its paces in Earth orbit,[43] and in May Apollo 10 conducted a "dress rehearsal" in lunar orbit. By July 1969, 

all was in readiness for Apollo 11 to take the final step onto the Moon.[44]

The Soviet Union appeared to be winning the Space Race by beating the US to firsts, but its early lead was overtaken by the US Gemini program and 

Soviet failure to develop the N1 launcher, which would have been comparable to the Saturn V.[45] The Soviets tried to beat the US to return lunar material to the Earth by 

means of uncrewed probes. On July 13, three days before Apollo 11's launch, the Soviet Union launched Luna 15, which reached lunar orbit before Apollo 11. 

During descent, a malfunction caused Luna 15 to crash in Mare Crisium about two hours before Armstrong and Aldrin took off from the Moon's surface to begin their voyage home. 

The Nuffield Radio Astronomy Laboratories radio telescope in England recorded transmissions from Luna 15 during its descent, and these were released in

 July 2009 for the 40th anniversary of Apollo 11.