Apollo 11

Apollo 11 was the that first  humans on the. Commander and lunar module pilot  formed the American crew that landed the  Eagle on July 20, 1969, at 20:17. 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 they collected 47.5 lb of lunar material to bring back to. Command module pilot flew the  alone in  while they were on the Moon's surface. Armstrong and Aldrin spent 21 hours, 36 minutes on the lunar surface at a site they named before lifting off to rejoin Columbia in lunar orbit.

Apollo 11 was launched by a rocket from  on, on July 16 at 13:32 UTC, and it was the fifth crewed mission of 's. The Apollo had three parts: a  with a cabin for the three astronauts, the only part that returned to Earth; a, which supported the command module with propulsion, electrical power, oxygen, and water; and a  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 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 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. They returned to Earth and 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." Apollo 11 effectively ended the and fulfilled a national goal proposed in 1961 by  : "before this decade is out, of landing a man on the Moon and returning him safely to the Earth."

Background
In the late 1950s and early 1960s, the United States was engaged in the, a geopolitical rivalry with the. On October 4, 1957, the Soviet Union launched, the first. 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. This precipitated the, and triggered the. responded to the Sputnik challenge by creating the (NASA), and initiating, which aimed to launch a man into. But on April 12, 1961, Soviet  became the first person in space, and the first to orbit the Earth. Nearly a month later, on May 5, 1961, 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,.

Since the Soviet Union had higher lift capacity s, 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.

On May 25, 1961, Kennedy addressed the 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."

On September 12, 1962, Kennedy before a crowd of about 40,000 people in the  in,. A widely quoted refrain from the middle portion of the speech reads as follows:

"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, ? Why does ? 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."

In spite of that, the proposed program faced the opposition of many Americans and was dubbed a "" by, a mathematician at the. The effort to land a man on the Moon already had a name:. When Kennedy met with, the 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 on September 20, 1963. The idea of a joint Moon mission was abandoned after Kennedy's death.

An early and crucial decision was choosing over both  and. A is an  in which two spacecraft navigate through space and meet up. In July 1962 NASA head announced that lunar orbit rendezvous would be used and that the  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. This design meant the spacecraft could be launched by a single rocket that was then under development.

Technologies and techniques required for Apollo were developed by. The Apollo project was enabled by NASA's adoption of new advances in, including s (MOSFETs) in the  (IMP) and   (IC) chips in the  (AGC).

Project Apollo was abruptly halted by the fire on January 27, 1967, in which astronauts, , and  died, and the subsequent investigation. In October 1968, evaluated the command module in Earth orbit, and in December  tested it in lunar orbit. In March 1969, put the lunar module through its paces in Earth orbit, and in May  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.

The Soviet Union competed with the US in the Space Race, but its early lead was lost through repeated failures in development of the, which was comparable to the Saturn V. The Soviets tried to beat the US to return lunar material to the Earth by means of. On July 13, three days before Apollo 11's launch, the Soviet Union launched, which reached lunar orbit before Apollo 11. During descent, a malfunction caused Luna 15 to crash in about two hours before Armstrong and Aldrin took off from the Moon's surface to begin their voyage home. The 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.

Prime crew
The initial crew assignment of Commander, Command Module Pilot (CMP) , and Lunar Module Pilot (LMP) on the backup crew for Apollo9 was officially announced on November 20, 1967. Lovell and Aldrin had previously flown together as the crew of. Due to design and manufacturing delays in the LM, Apollo8 and Apollo9 swapped prime and backup crews, and Armstrong's crew became the backup for Apollo8. Based on the normal crew rotation scheme, Armstrong was then expected to command Apollo 11.

There would be one change. , the CMP on the Apollo8 crew, began experiencing trouble with his legs. Doctors diagnosed the problem as a bony growth between his fifth and sixth vertebrae, requiring surgery. Lovell took his place on the Apollo8 crew, and when Collins recovered he joined Armstrong's crew as CMP. In the meantime, filled in as backup LMP, and Aldrin as backup CMP for Apollo 8. Apollo 11 was the second American mission where all the crew members had prior spaceflight experience, the first being Apollo 10. The next was in 1988.

gave Armstrong the option to replace Aldrin with Lovell, since some thought Aldrin was difficult to work with. Armstrong had no issues working with Aldrin, but thought it over for a day before declining. He thought Lovell deserved to command his own mission (eventually ).

The Apollo 11 prime crew had none of the close cheerful camaraderie characterized by that of. Instead they forged an amiable working relationship. Armstrong in particular was notoriously aloof, but Collins, who considered himself a loner, confessed to rebuffing Aldrin's attempts to create a more personal relationship. Aldrin and Collins described the crew as "amiable strangers". Armstrong did not agree with the assessment, and said "... all the crews I was on worked very well together."

Backup crew
The backup crew consisted of Lovell as Commander, as CMP, and Haise as LMP. Anders had flown with Lovell on Apollo8. In early 1969, he accepted a job with the effective August 1969, and announced he would retire as an astronaut at that time. was moved from the support crew into parallel training with Anders as backup CMP in case Apollo 11 was delayed past its intended July launch date, at which point Anders would be unavailable. Lovell, Haise, and Mattingly were later assigned as the prime crew of.

Support crew
During Projects Mercury and Gemini, each mission had a prime and a backup crew. For Apollo, a third crew of astronauts was added, known as the support crew. The support crew maintained the flight plan, checklists and mission ground rules, and ensured the prime and backup crews were apprised of changes. They developed procedures, especially those for emergency situations, so these were ready for when the prime and backup crews came to train in the simulators, allowing them to concentrate on practicing and mastering them. For Apollo 11, the support crew consisted of Ken Mattingly, and.

Capsule communicators
The (CAPCOM) was an astronaut at the  in, who was the only person who communicated directly with the flight crew. For Apollo 11, the CAPCOMs were:, Ronald Evans, , James Lovell, William Anders, Ken Mattingly, Fred Haise, , and.

Flight directors
The for this mission were:

Other key personnel
Other key personnel who played important roles in the Apollo 11 mission include the following.

Insignia
The Apollo 11 was designed by Collins, who wanted a symbol for "peaceful lunar landing by the United States". At Lovell's suggestion, he chose the, the of the United States, as the symbol. Tom Wilson, a simulator instructor, suggested an in its beak to represent their peaceful mission. Collins added a lunar background with the Earth in the distance. The sunlight in the image was coming from the wrong direction; the shadow should have been in the lower part of the Earth instead of the left. Aldrin, Armstrong and Collins decided the Eagle and the Moon would be in their natural colors, and decided on a blue and gold border. Armstrong was concerned that "eleven" would not be understood by non-English speakers, so they went with "Apollo 11", and they decided not to put their names on the patch, so it would "be representative of everyone who had worked toward a lunar landing".

An illustrator at the MSC did the artwork, which was then sent off to NASA officials for approval. The design was rejected. , the director of the MSC felt the talons of the eagle looked "too warlike". After some discussion, the olive branch was moved to the talons. When the was released in 1971, the patch design provided the eagle for its reverse side. The design was also used for the smaller unveiled in 1979.

Call signs
After the crew of Apollo 10 named their spacecraft Charlie Brown and Snoopy, assistant manager for public affairs wrote to, the Manager of the Apollo Spacecraft Program Office at the  (MSC), to suggest the Apollo 11 crew be less flippant in naming their craft. The name Snowcone was used for the CM and Haystack was used for the LM in both internal and external communications during early mission planning.

The LM was named Eagle after the motif which was featured prominently on the mission insignia. At Scheer's suggestion, the CM was named ' after ', the giant cannon that launched a spacecraft (also from Florida) in 's 1865 novel . It also referenced, a historical name of the United States. In Collins' 1976 book, he said Columbia was in reference to.

Mementos
The astronauts had personal preference kits (PPKs), small bags containing personal items of significance they wanted to take with them on the mission. Five 0.5 lb PPKs were carried on Apollo 11: three (one for each astronaut) were stowed on Columbia before launch, and two on Eagle.

Neil Armstrong's LM PPK contained a piece of wood from the ' 1903 's left propeller and a piece of fabric from its wing, along with a diamond-studded originally given to Slayton by the widows of the Apollo1 crew. This pin had been intended to be flown on that mission and given to Slayton afterwards, but following the disastrous launch pad fire and subsequent funerals, the widows gave the pin to Slayton. Armstrong took it with him on Apollo 11.

Site selection
NASA's Apollo Site Selection Board announced five potential landing sites on February 8, 1968. These were the result of two years' worth of studies based on high-resolution photography of the lunar surface by the five uncrewed probes of the and information about surface conditions provided by the. The best Earth-bound telescopes could not resolve features with the resolution Project Apollo required. The landing site had to be close to the lunar equator to minimize the amount of propellant required, clear of obstacles to minimize maneuvering, and flat to simplify the task of the landing radar. Scientific value was not a consideration.

Areas that appeared promising on photographs taken on Earth were often found to be totally unacceptable. The original requirement that the site be free of craters had to be relaxed, as no such site was found. Five sites were considered: Sites1 and2 were in the Sea of Tranquility ('); Site3 was in the Central Bay ('); and Sites4 and5 were in the Ocean of Storms (). The final site selection was based on seven criteria:
 * The site needed to be smooth, with relatively few craters;
 * with approach paths free of large hills, tall cliffs or deep craters that might confuse the landing radar and cause it to issue incorrect readings;
 * reachable with a minimum amount of propellant;
 * allowing for delays in the launch countdown;
 * providing the Apollo spacecraft with a free-return trajectory, one that would allow it to coast around the Moon and safely return to Earth without requiring any engine firings should a problem arise on the way to the Moon;
 * with good visibility during the landing approach, meaning the Sun would be between 7and 20 degrees behind the LM; and
 * a general slope of less than two degrees in the landing area.

The requirement for the Sun angle was particularly restrictive, limiting the launch date to one day per month. A landing just after dawn was chosen to limit the temperature extremes the astronauts would experience. The Apollo Site Selection Board selected Site2, with Sites 3and5 as backups in the event of the launch being delayed. In May 1969, Apollo 10's lunar module flew to within 15 km of Site2, and reported it was acceptable.

First-step decision
During the first press conference after the Apollo 11 crew was announced, the first question was, "Which one of you gentlemen will be the first man to step onto the lunar surface?" Slayton told the reporter it had not been decided, and Armstrong added that it was "not based on individual desire".

One of the first versions of the egress checklist had the lunar module pilot exit the spacecraft before the commander, which matched what had been done on Gemini missions, where the commander had never performed the spacewalk. Reporters wrote in early 1969 that Aldrin would be the first man to walk on the Moon, and Associate Administrator told reporters he would be first as well. Aldrin heard that Armstrong would be the first because Armstrong was a civilian, which made Aldrin livid. Aldrin attempted to persuade other lunar module pilots he should be first, but they responded cynically about what they perceived as a lobbying campaign. Attempting to stem interdepartmental conflict, Slayton told Aldrin that Armstrong would be first since he was the commander. The decision was announced in a press conference on April 14, 1969.

For decades, Aldrin believed the final decision was largely driven by the lunar module's hatch location. Because the astronauts had their spacesuits on and the spacecraft was so small, maneuvering to exit the spacecraft was difficult. The crew tried a simulation in which Aldrin left the spacecraft first, but he damaged the simulator while attempting to egress. While this was enough for mission planners to make their decision, Aldrin and Armstrong were left in the dark on the decision until late spring. Slayton told Armstrong the plan was to have him leave the spacecraft first, if he agreed. Armstrong said, "Yes, that's the way to do it."

The media accused Armstrong of exercising his commander's prerogative to exit the spacecraft first. revealed in his 2001 autobiography that a meeting occurred between Gilruth, Slayton, Low, and himself to make sure Aldrin would not be the first to walk on the Moon. They argued that the first person to walk on the Moon should be like, a calm and quiet person. They made the decision to change the flight plan so the commander was the first to egress from the spacecraft.

Pre-launch
The ascent stage of lunar module LM-5 arrived at the on January 8, 1969, followed by the descent stage four days later, and Command and Service Module CM-107 on January 23. There were several differences between LM-5 and Apollo 10's LM-4; LM-5 had a VHF radio antenna to facilitate communication with the astronauts during their EVA on the lunar surface; a lighter ascent engine; more thermal protection on the landing gear; and a package of scientific experiments known as the (EASEP). The only change in the configuration of the command module was the removal of some insulation from the forward hatch. The command and service modules were mated on January 29, and moved from the to the  on April 14.

The third stage of Saturn V AS-506 had arrived on January 18, followed by the  second stage on February 6,  first stage on February 20, and the  on February 27. At 1230 on May 20, the 5443 t assembly departed the Vehicle Assembly Building atop the, bound for Launch Pad 39A, part of , while Apollo 10 was still on its way to the Moon. A countdown test commenced on June 26, and concluded on July 2. The launch complex was floodlit on the night of July 15, when the crawler-transporter carried the back to its parking area. In the early hours of the morning, the fuel tanks of the S-II and S-IVB stages were filled with. Fueling was completed by three hours before launch. Launch operations were partly automated, with 43 programs written in the.

Slayton roused the crew shortly after 0400, and they showered, shaved, and had the traditional pre-flight breakfast of steak and eggs with Slayton and the backup crew. They then donned their space suits and began breathing pure oxygen. At 0630, they headed out to Launch Complex 39. Haise entered Columbia about three hours and ten minutes before launch time. Along with a technician, he helped Armstrong into the left hand couch at 06:54. Five minutes later, Collins joined him, taking up his position on the right hand couch. Finally, Aldrin entered, taking the center couch. Haise left around two hours and ten minutes before launch. The closeout crew sealed the hatch, and the cabin was purged and pressurized. The closeout crew then left the launch complex about an hour before launch time. The countdown became automated at three minutes and twenty seconds before launch time. Over 450 personnel were at the consoles in the.

Launch and flight to lunar orbit
An estimated one million spectators watched the launch of Apollo 11 from the highways and beaches in the vicinity of the launch site. Dignitaries included the, , four , 19 , 40 , 60 s and 200. viewed the launch with the former president, and his wife. Around 3,500 media representatives were present. About two-thirds were from the United States; the rest came from 55 other countries. The launch was televised live in 33 countries, with an estimated 25 million viewers in the United States alone. Millions more around the world listened to radio broadcasts. President viewed the launch from his office in the  with his NASA liaison officer, Apollo astronaut.

Saturn V AS-506 launched Apollo 11 on July 16, 1969, at 13:32:00 (9:32:00 ). At 13.2 seconds into the flight, the launch vehicle began to into its  of 72.058°. Full shutdown of the first-stage engines occurred about 2minutes and 42 seconds into the mission, followed by separation of the S-IC and ignition of the S-II engines. The second stage engines then cut off and separated at about 9minutes and 8seconds, allowing the first ignition of the S-IVB engine a few seconds later.

Apollo 11 entered Earth orbit at an altitude of 100.4 nmi by 98.9 nmi, twelve minutes into its flight. After one and a half orbits, a second ignition of the S-IVB engine pushed the spacecraft onto its trajectory toward the Moon with the (TLI) burn at 16:22:13 UTC. About 30 minutes later, with Collins in the left seat and at the controls, the maneuver was performed. This involved separating Columbia from the spent S-IVB stage, turning around, and docking with Eagle still attached to the stage. After the LM was extracted, the combined spacecraft headed for the Moon, while the rocket stage flew on a trajectory past the Moon. This was done to avoid the third stage colliding with the spacecraft, the Earth, or the Moon. A from passing around the Moon threw it into an.

On July 19 at 17:21:50 UTC, Apollo 11 passed behind the Moon and fired its service propulsion engine to enter. In the thirty orbits that followed, the crew saw passing views of their landing site in the southern Sea of Tranquility about 12 mi southwest of the crater. The site was selected in part because it had been characterized as relatively flat and smooth by the automated and  landers and the Lunar Orbiter mapping spacecraft and unlikely to present major landing or EVA challenges. It lay about 25 km southeast of the Surveyor5 landing site, and 68 km southwest of Ranger8's crash site.

Lunar descent
At 12:52:00 UTC on July 20, Aldrin and Armstrong entered Eagle, and began the final preparations for lunar descent. At 17:44:00 Eagle separated from Columbia. Collins, alone aboard Columbia, inspected Eagle as it pirouetted before him to ensure the craft was not damaged, and that the landing gear was correctly deployed. Armstrong exclaimed: "The Eagle has wings!"

As the descent began, Armstrong and Aldrin found themselves passing landmarks on the surface two or three seconds early, and reported that they were "long"; they would land miles west of their target point. Eagle was traveling too fast. The problem could have been —concentrations of high mass that could have altered the trajectory. Flight Director Gene Kranz speculated that it could have resulted from extra air pressure in the docking tunnel. Or it could have been the result of Eagle's pirouette maneuver.

Five minutes into the descent burn, and 6000 ft above the surface of the Moon, the (LGC) distracted the crew with the first of several unexpected 1201 and 1202 program alarms. Inside Mission Control Center, computer engineer told   it was safe to continue the descent, and this was relayed to the crew. The program alarms indicated "executive overflows", meaning the guidance computer could not complete all its tasks in real time and had to postpone some of them. , the Director of Apollo Flight Computer Programming at the  later recalled:

"To blame the computer for the Apollo 11 problems is like blaming the person who spots a fire and calls the fire department. Actually, the computer was programmed to do more than recognize error conditions. A complete set of recovery programs was incorporated into the software. The software's action, in this case, was to eliminate lower priority tasks and re-establish the more important ones. The computer, rather than almost forcing an abort, prevented an abort. If the computer hadn't recognized this problem and taken recovery action, I doubt if Apollo 11 would have been the successful Moon landing it was."

During the mission, the cause was diagnosed as the rendezvous radar switch being in the wrong position, causing the computer to process data from both the rendezvous and landing radars at the same time. Software engineer concluded in a 2005 Guidance and Control Conference paper that the problem was due to a hardware design bug previously seen during testing of the first uncrewed LM in. Having the rendezvous radar on (so it was warmed up in case of an emergency landing abort) should have been irrelevant to the computer, but an electrical phasing mismatch between two parts of the rendezvous radar system could cause the stationary antenna to appear to the computer as dithering back and forth between two positions, depending upon how the hardware randomly powered up. The extra spurious, as the rendezvous radar updated an involuntary counter, caused the computer alarms.

Landing
When Armstrong again looked outside, he saw that the computer's landing target was in a boulder-strewn area just north and east of a 300 ft crater (later determined to be ), so he took semi-automatic control. Armstrong considered landing short of the boulder field so they could collect geological samples from it, but could not since their horizontal velocity was too high. Throughout the descent, Aldrin called out navigation data to Armstrong, who was busy piloting Eagle. Now 107 ft above the surface, Armstrong knew their propellant supply was dwindling and was determined to land at the first possible landing site.

Armstrong found a clear patch of ground and maneuvered the spacecraft towards it. As he got closer, now 250 ft above the surface, he discovered his new landing site had a crater in it. He cleared the crater and found another patch of level ground. They were now 100 ft from the surface, with only 90 seconds of propellant remaining. Lunar dust kicked up by the LM's engine began to impair his ability to determine the spacecraft's motion. Some large rocks jutted out of the dust cloud, and Armstrong focused on them during his descent so he could determine the spacecraft's speed.

A light informed Aldrin that at least one of the 67 in probes hanging from Eagle footpads had touched the surface a few moments before the landing and he said: "Contact light!" Armstrong was supposed to immediately shut the engine down, as the engineers suspected the pressure caused by the engine's own exhaust reflecting off the lunar surface could make it explode, but he forgot. Three seconds later, Eagle landed and Armstrong shut the engine down. Aldrin immediately said "Okay, engine stop. ACA—out of ." Armstrong acknowledged: "Out of detent. Auto." Aldrin continued: "Mode control—both auto. Descent engine command override off. Engine arm—off. 413 is in."

ACA was the —the LM's control stick. Output went to the LGC to command the (RCS) jets to fire. "Out of Detent" meant the stick had moved away from its centered position; it was spring-centered like the turn indicator in a car. LGC address 413 contained the variable that indicated the LM had landed.

Eagle landed at 20:17:40 UTC on Sunday July 20 with 216 lb of usable fuel remaining. Information available to the crew and mission controllers during the landing showed the LM had enough fuel for another 25 seconds of powered flight before an abort without touchdown would have become unsafe, but post-mission analysis showed that the real figure was probably closer to 50 seconds. Apollo 11 landed with less fuel than most subsequent missions, and the astronauts encountered a premature low fuel warning. This was later found to be the result of greater propellant 'slosh' than expected, uncovering a fuel sensor. On subsequent missions, extra anti-slosh baffles were added to the tanks to prevent this.

Armstrong acknowledged Aldrin's completion of the post landing checklist with "Engine arm is off", before responding to the CAPCOM, Charles Duke, with the words, "Houston, here. The Eagle has landed." Armstrong's unrehearsed change of call sign from "Eagle" to "Tranquility Base" emphasized to listeners that landing was complete and successful. Duke mispronounced his reply as he expressed the relief at Mission Control: "Roger, Twan—Tranquility, we copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again. Thanks a lot."

Two and a half hours after landing, before preparations began for the EVA, Aldrin radioed to Earth: "This is the LM pilot. I'd like to take this opportunity to ask every person listening in, whoever and wherever they may be, to pause for a moment and contemplate the events of the past few hours and to give thanks in his or her own way."

He then took privately. At this time NASA was still fighting a lawsuit brought by atheist (who had objected to the ) demanding that their astronauts refrain from broadcasting religious activities while in space. As such, Aldrin chose to refrain from directly mentioning taking communion on the Moon. Aldrin was an elder at the, and his communion kit was prepared by the pastor of the church, Dean Woodruff. Webster Presbyterian possesses the chalice used on the Moon and commemorates the event each year on the Sunday closest to July 20. The schedule for the mission called for the astronauts to follow the landing with a five-hour sleep period, but they chose to begin preparations for the EVA early, thinking they would be unable to sleep.

Lunar surface operations
Preparations for and  to walk on the Moon began at 23:43. These took longer than expected; three and a half hours instead of two. During training on Earth, everything required had been neatly laid out in advance, but on the Moon the cabin contained a large number of other items as well, such as checklists, food packets, and tools. Six hours and thirty-nine minutes after landing Armstrong and Aldrin were ready to go outside, and Eagle was depressurized.

Eagle's hatch was opened at 02:39:33. Armstrong initially had some difficulties squeezing through the hatch with his (PLSS). Some of the highest heart rates recorded from Apollo astronauts occurred during LM egress and ingress. At 02:51 Armstrong began his descent to the lunar surface. The remote control unit on his chest kept him from seeing his feet. Climbing down the nine-rung ladder, Armstrong pulled a D-ring to deploy the modular equipment stowage assembly (MESA) folded against Eagle side and activate the TV camera.

Apollo 11 used (TV) incompatible with broadcast TV, so it was displayed on a special monitor, and a conventional TV camera viewed this monitor, significantly reducing the quality of the picture. The signal was received at in the United States, but with better fidelity by  near  in Australia. Minutes later the feed was switched to the more sensitive in Australia. Despite some technical and weather difficulties, ghostly black and white images of the first lunar EVA were received and broadcast to at least 600 million people on Earth. Copies of this video in broadcast format were saved and are widely available, but were likely destroyed during routine magnetic tape re-use at NASA.

While still on the ladder, Armstrong uncovered a mounted on the LM descent stage bearing two drawings of Earth (of the Western and Eastern Hemispheres), an inscription, and signatures of the astronauts and President Nixon. The inscription read: "Here men from the planet Earth first set foot upon the Moon July 1969, A.D. We came in peace for all mankind."

At the behest of the to add a reference to God, NASA included the vague date as a reason to include A.D., which stands for, "in the year of our Lord" (although it should have been placed before the year, not after).

After describing the surface dust as "very fine-grained" and "almost like a powder", at 02:56:15, six and a half hours after landing, Armstrong stepped off Eagle footpad and declared: "That's one small step for [a] man, one giant leap for mankind."

Armstrong intended to say "That's one small step for a man", but the word "a" is not audible in the transmission, and thus was not initially reported by most observers of the live broadcast. When later asked about his quote, Armstrong said he believed he said "for a man", and subsequent printed versions of the quote included the "a" in square brackets. One explanation for the absence may be that his accent caused him to slur the words "for a" together; another is the intermittent nature of the audio and video links to Earth, partly because of storms near Parkes Observatory. More recent digital analysis of the tape claims to reveal the "a" may have been spoken but obscured by static.

About seven minutes after stepping onto the Moon's surface, Armstrong collected a contingency soil sample using a sample bag on a stick. He then folded the bag and tucked it into a pocket on his right thigh. This was to guarantee there would be some lunar soil brought back in case an emergency required the astronauts to abandon the EVA and return to the LM. Twelve minutes after the sample was collected, he removed the TV camera from the MESA and made a panoramic sweep, then mounted it on a tripod. The TV camera cable remained partly coiled and presented a tripping hazard throughout the EVA. Still photography was accomplished with a camera which could be operated hand held or mounted on Armstrong's. Aldrin joined Armstrong on the surface. He described the view with the simple phrase: "Magnificent desolation."

Armstrong said moving in the, one-sixth of Earth's, was "even perhaps easier than the simulations ... It's absolutely no trouble to walk around." Aldrin joined him on the surface and tested methods for moving around, including two-footed kangaroo hops. The PLSS backpack created a tendency to tip backward, but neither astronaut had serious problems maintaining balance. Loping became the preferred method of movement. The astronauts reported that they needed to plan their movements six or seven steps ahead. The fine soil was quite slippery. Aldrin remarked that moving from sunlight into Eagle shadow produced no temperature change inside the suit, but the helmet was warmer in sunlight, so he felt cooler in shadow. The MESA failed to provide a stable work platform and was in shadow, slowing work somewhat. As they worked, the moonwalkers kicked up gray dust which soiled the outer part of their suits.

The astronauts planted the containing a  on the lunar surface, in clear view of the TV camera. Aldrin remembered, "Of all the jobs I had to do on the Moon the one I wanted to go the smoothest was the flag raising." But the astronauts struggled with the telescoping rod and could only jam the pole a couple of inches (5 cm) into the hard lunar surface. Aldrin was afraid it might topple in front of TV viewers. But he gave "a crisp West Point salute". Before Aldrin could take a photo of Armstrong with the flag, President Richard Nixon spoke to them through a telephone-radio transmission which Nixon called "the most historic phone call ever made from the White House." Nixon originally had a long speech prepared to read during the phone call, but Frank Borman, who was at the White House as a NASA liaison during Apollo 11, convinced Nixon to keep his words brief. "Nixon: Hello, Neil and Buzz. I'm talking to you by telephone from the Oval Room at the White House. And this certainly has to be the most historic telephone call ever made. I just can't tell you how proud we all are of what you've done. For every American, this has to be the proudest day of our lives. And for people all over the world, I am sure they too join with Americans in recognizing what an immense feat this is. Because of what you have done, the heavens have become a part of man's world. And as you talk to us from the Sea of Tranquility, it inspires us to redouble our efforts to bring peace and tranquility to Earth. For one priceless moment in the whole history of man, all the people on this Earth are truly one: one in their pride in what you have done, and one in our prayers that you will return safely to Earth. Armstrong: Thank you, Mr. President. It's a great honor and privilege for us to be here, representing not only the United States, but men of peace of all nations, and with interest and curiosity, and men with a vision for the future. It's an honor for us to be able to participate here today."

They deployed the, which included a passive seismic experiment package used to measure s and a array used for the. Then Armstrong walked 196 ft from the LM to snap photos at the rim of while Aldrin collected two s. He used the  to pound in the tubes—the only time the hammer was used on Apollo 11—but was unable to penetrate more than 6 in deep. The astronauts then collected rock samples using scoops and tongs on extension handles. Many of the surface activities took longer than expected, so they had to stop documenting sample collection halfway through the allotted 34 minutes. Aldrin shoveled 6 kg of soil into the box of rocks in order to pack them in tightly. Two types of rocks were found in the geological samples: and. Three new minerals were discovered in the rock samples collected by the astronauts:, , and. Armalcolite was named after Armstrong, Aldrin, and Collins. All have subsequently been found on Earth.

Mission Control used a coded phrase to warn Armstrong his metabolic rates were high, and that he should slow down. He was moving rapidly from task to task as time ran out. As metabolic rates remained generally lower than expected for both astronauts throughout the walk, Mission Control granted the astronauts a 15-minute extension. In a 2010 interview, Armstrong explained that NASA limited the first moonwalk's time and distance because there was no empirical proof of how much cooling water the astronauts' PLSS backpacks would consume to handle their body heat generation while working on the Moon.

Lunar ascent
Aldrin entered Eagle first. With some difficulty the astronauts lifted film and two sample boxes containing 21.55 kg of lunar surface material to the LM hatch using a flat cable pulley device called the Lunar Equipment Conveyor (LEC). This proved to be an inefficient tool, and later missions preferred to carry equipment and samples up to the LM by hand. Armstrong reminded Aldrin of a bag of memorial items in his sleeve pocket, and Aldrin tossed the bag down. Armstrong then jumped onto the ladder's third rung, and climbed into the LM. After transferring to LM, the explorers lightened the ascent stage for the return to lunar orbit by tossing out their PLSS backpacks, lunar overshoes, an empty Hasselblad camera, and other equipment. The hatch was closed again at 05:11:13. They then pressurized the LM and settled down to sleep.

Presidential speech writer had prepared an In Event of Moon Disaster announcement for Nixon to read in the event the Apollo 11 astronauts were stranded on the Moon. The remarks were in a memo from Safire to Nixon's, in which Safire suggested a protocol the administration might follow in reaction to such a disaster. According to the plan, Mission Control would "close down communications" with the LM, and a clergyman would "commend their souls to the deepest of the deep" in a public ritual likened to. The last line of the prepared text contained an allusion to 's First World War poem, "".

While moving inside the cabin, Aldrin accidentally damaged the that would arm the main engine for lift off from the Moon. There was a concern this would prevent firing the engine, stranding them on the Moon. A felt-tip pen was sufficient to activate the switch; had this not worked, the LM circuitry could have been reconfigured to allow firing the ascent engine.

After more than $21 1/2$ hours on the lunar surface, in addition to the scientific instruments, the astronauts left behind: an mission patch in memory of astronauts, , and , who died when their command module caught fire during a test in January 1967; two memorial medals of Soviet cosmonauts  and , who died in 1967 and 1968 respectively; a memorial bag containing a gold replica of an olive branch as a traditional symbol of peace; and a silicon message disk carrying the  by Presidents Eisenhower, Kennedy, Johnson, and Nixon along with messages from leaders of 73 countries around the world. The disk also carries a listing of the leadership of the US Congress, a listing of members of the four committees of the House and Senate responsible for the NASA legislation, and the names of NASA's past and present top management.

After about seven hours of rest, the crew was awakened by Houston to prepare for the return flight. Two and a half hours later, at 17:54:00 UTC, they lifted off in Eagle ascent stage to rejoin Collins aboard Columbia in lunar orbit. Film taken from the LM ascent stage upon liftoff from the Moon reveals the American flag, planted some 25 ft from the descent stage, whipping violently in the exhaust of the ascent stage engine. Aldrin looked up in time to witness the flag topple: "The ascent stage of the LM separated ... I was concentrating on the computers, and Neil was studying the, but I looked up long enough to see the flag fall over." Subsequent Apollo missions planted their flags farther from the LM.

Columbia in lunar orbit
During his day flying solo around the Moon, Collins never felt lonely. Although it has been said "not since has any human known such solitude", Collins felt very much a part of the mission. In his autobiography he wrote: "this venture has been structured for three men, and I consider my third to be as necessary as either of the other two". In the 48 minutes of each orbit when he was out of radio contact with the Earth while Columbia passed round the far side of the Moon, the feeling he reported was not fear or loneliness, but rather "awareness, anticipation, satisfaction, confidence, almost exultation".

One of Collins' first tasks was to identify the lunar module on the ground. To give Collins an idea where to look, Mission Control radioed that they believed the lunar module landed about four miles off target. Each time he passed over the suspected lunar landing site, he tried in vain to find the module. On his first orbits on the back side of the Moon, Collins performed maintenance activities such as dumping excess water produced by the s and preparing the cabin for Armstrong and Aldrin to return.

Just before he reached the dark side on the third orbit, Mission Control informed Collins there was a problem with the temperature of the coolant. If it became too cold, parts of Columbia might freeze. Mission Control advised him to assume manual control and implement Environmental Control System Malfunction Procedure 17. Instead, Collins flicked the switch on the system from automatic to manual and back to automatic again, and carried on with normal housekeeping chores, while keeping an eye on the temperature. When Columbia came back around to the near side of the Moon again, he was able to report that the problem had been resolved. For the next couple of orbits, he described his time on the back side of the Moon as "relaxing". After Aldrin and Armstrong completed their EVA, Collins slept so he could be rested for the rendezvous. While the flight plan called for Eagle to meet up with Columbia, Collins was prepared for a contingency in which he would fly Columbia down to meet Eagle.

Return
Eagle rendezvoused with Columbia at 21:24 UTC on July 21, and the two docked at 21:35. Eagle's ascent stage was jettisoned into lunar orbit at 23:41. Just before the flight, it was noted that Eagle was still likely to be orbiting the Moon. Later NASA reports mentioned that Eagle orbit had decayed, resulting in it impacting in an "uncertain location" on the lunar surface.

On July 23, the last night before splashdown, the three astronauts made a television broadcast in which Collins commented: "... The Saturn V rocket which put us in orbit is an incredibly complicated piece of machinery, every piece of which worked flawlessly ... We have always had confidence that this equipment will work properly. All this is possible only through the blood, sweat, and tears of a number of people ... All you see is the three of us, but beneath the surface are thousands and thousands of others, and to all of those, I would like to say, "Thank you very much.""

Aldrin added: "This has been far more than three men on a mission to the Moon; more, still, than the efforts of a government and industry team; more, even, than the efforts of one nation. We feel that this stands as a symbol of the insatiable curiosity of all mankind to explore the unknown ... Personally, in reflecting on the events of the past several days, a verse from Psalms comes to mind. "When I consider the heavens, the work of Thy fingers, the Moon and the stars, which Thou hast ordained; What is man that Thou art mindful of him?""

Armstrong concluded: "The responsibility for this flight lies first with history and with the giants of science who have preceded this effort; next with the American people, who have, through their will, indicated their desire; next with four administrations and their Congresses, for implementing that will; and then, with the agency and industry teams that built our spacecraft, the Saturn, the Columbia, the Eagle, and the little, the spacesuit and backpack that was our small spacecraft out on the lunar surface. We would like to give special thanks to all those Americans who built the spacecraft; who did the construction, design, the tests, and put their hearts and all their abilities into those craft. To those people tonight, we give a special thank you, and to all the other people that are listening and watching tonight, God bless you. Good night from Apollo 11.""

On the return to Earth, a bearing at the Guam tracking station failed, potentially preventing communication on the last segment of the Earth return. A regular repair was not possible in the available time but the station director, Charles Force, had his ten-year-old son Greg use his small hands to reach into the housing and pack it with grease. Greg was later thanked by Armstrong.

Splashdown and quarantine
The USS Hornet (CV-12), under the command of , was selected as the primary recovery ship (PRS) for Apollo 11 on June 5, replacing its sister ship, the  USS Princeton (LPH-5), which had recovered Apollo 10 on May 26. Hornet was then at her home port of. On reaching on July 5, Hornet  the  helicopters of, a unit which specialized in recovery of Apollo spacecraft, specialized divers of  Detachment Apollo, a 35-man NASA recovery team, and about 120 media representatives. To make room, most of Hornet's air wing was left behind in Long Beach. Special recovery equipment was also loaded, including a command module used for training.

On July 12, with Apollo 11 still on the launch pad, Hornet departed Pearl Harbor for the recovery area in the central Pacific, in the vicinity of 10.6°N, 172.4°W. A presidential party consisting of Nixon, Borman,  and   flew to  on, then to the  USS Arlington (AGMR-2) in. After a night on board, they would fly to Hornet in Marine One for a few hours of ceremonies. On arrival aboard Hornet, the party was greeted by the, , and  , who flew to Hornet from  in one of Hornet's  aircraft.

Weather satellites were not yet common, but US Air Force Hank Brandli had access to top secret spy satellite images. He realized that a storm front was headed for the Apollo recovery area. Poor visibility which could make locating the capsule difficult, and strong upper level winds which "would have ripped their parachutes to shreds" according to Brandli; posed a serious threat to the safety of the mission. Brandli alerted Navy Captain Willard S. Houston Jr., the commander of the at Pearl Harbor, who had the required security clearance. On their recommendation,, commander of Manned Spaceflight Recovery Forces, Pacific, advised NASA to change the recovery area, each man risking their careers. A new location was selected 215 nmi northeast.

This altered the flight plan. A different sequence of computer programs was used, one never before attempted. In a conventional entry, P64 was followed by P67. For a skip-out re-entry, P65 and P66 were employed to handle the exit and entry parts of the skip. In this case, because they were extending the re-entry but not actually skipping out, P66 was not invoked and instead P65 led directly to P67. The crew were also warned they would not be in a full-lift (heads-down) attitude when they entered P67. The first program's acceleration subjected the astronauts to 6.5 g0; the second, to 6.0 g0.

Before dawn on July 24, Hornet launched four Sea King helicopters and three s. Two of the E-1s were designated as "air boss" while the third acted as a communications relay aircraft. Two of the Sea Kings carried divers and recovery equipment. The third carried photographic equipment, and the fourth carried the decontamination swimmer and the flight surgeon. At 16:44 UTC (05:44 local time) Columbia's s were deployed. This was observed by the helicopters. Seven minutes later Columbia struck the water forcefully 2660 km east of, 380 km south of Johnston Atoll, and 24 km from Hornet, at 13.31667°N, -169.15°W. 72 F with 6 ft seas and winds at 17 knot from the east were reported under broken clouds at 1500 ft with visibility of 10 NM at the recovery site. Reconnaissance aircraft flying to the original splashdown location reported the conditions Brandli and Houston had predicted.

During, Columbia landed upside down but was righted within ten minutes by flotation bags activated by the astronauts. A diver from the Navy helicopter hovering above attached a to prevent it from drifting. More divers attached flotation collars to stabilize the module and positioned rafts for astronaut extraction.

The divers then passed biological isolation garments (BIGs) to the astronauts, and assisted them into the life raft. The possibility of bringing back s from the lunar surface was considered remote, but NASA took precautions at the recovery site. The astronauts were rubbed down with a solution and Columbia wiped with  to remove any lunar dust that might be present. The astronauts were winched on board the recovery helicopter. BIGs were worn until they reached isolation facilities on board Hornet. The raft containing decontamination materials was intentionally sunk.

After touchdown on Hornet at 17:53 UTC, the helicopter was lowered by the elevator into the hangar bay, where the astronauts walked the 30 ft to the (MQF), where they would begin the Earth-based portion of their 21 days of quarantine. This practice would continue for two more Apollo missions, Apollo 12 and, before the Moon was proven to be barren of life, and the quarantine process dropped. Nixon welcomed the astronauts back to Earth. He told them: "As a result of what you've done, the world has never been closer together before."

After Nixon departed, Hornet was brought alongside the 5 ST Columbia, which was lifted aboard by the ship's crane, placed on a and moved next to the MQF. It was then attached to the MQF with a flexible tunnel, allowing the lunar samples, film, data tapes and other items to be removed. Hornet returned to Pearl Harbor, where the MQF was loaded onto a and airlifted to the Manned Spacecraft Center. The astronauts arrived at the at 10:00 UTC on July 28. Columbia was taken to for deactivation, and its pyrotechnics made safe. It was then taken to, from whence it was flown to Houston in a , reaching the Lunar Receiving Laboratory on July 30.

In accordance with the, a set of regulations promulgated by NASA on July 16 to codify its quarantine protocol, the astronauts continued in quarantine. After three weeks in confinement (first in the Apollo spacecraft, then in their trailer on Hornet, and finally in the Lunar Receiving Laboratory), the astronauts were given a clean bill of health. On August 10, 1969, the Interagency Committee on Back Contamination met in Atlanta and lifted the quarantine on the astronauts, on those who had joined them in quarantine (NASA physician and MQF project engineer ), and on Columbia itself. Loose equipment from the spacecraft remained in isolation until the lunar samples were released for study.

Celebrations
On August 13, the three astronauts rode in s in their honor in New York and Chicago, with an estimated six million attendees. On the same evening in Los Angeles there was an official to celebrate the flight, attended by members of Congress, 44 governors, the, and ambassadors from 83 nations at the. Nixon and Agnew honored each astronaut with a presentation of the.

The three astronauts spoke before a on September 16, 1969. They presented two US flags, one to the and the other to the, that they had carried with them to the surface of the Moon. The on Apollo 11 is on display at the  in Pago Pago, the capital of American Samoa.

This celebration began a 38-day world tour that brought the astronauts to 22 foreign countries and included visits with the leaders of many countries. The crew toured from September 29 to November 5. Many nations honored the first human with special features in magazines or by issuing Apollo 11 commemorative postage stamps or coins.

Cultural significance
Humans walking on the Moon and returning safely to Earth accomplished Kennedy's goal set eight years earlier. In Mission Control during the Apollo 11 landing, Kennedy's speech flashed on the screen, followed by the words "TASK ACCOMPLISHED, July 1969". The success of Apollo 11 demonstrated the United States' technological superiority; and with the success of Apollo 11, America had won the Space Race.

New phrases permeated into the English language. "If they can send a man to the Moon, why can't they ...?" became a common saying following Apollo 11. Armstrong's words on the lunar surface also spun off various parodies.

While most people celebrated the accomplishment, disenfranchised Americans saw it as a symbol of the divide in America, evidenced by protesters outside of Kennedy Space Center the day before Apollo 11 launched. This is not to say they were not awed by it. , leading a protest march, was so captivated by the spectacle of the Apollo 11 launch that he forgot what he was going to say. Racial and financial inequalities frustrated citizens who wondered why money spent on the Apollo program was not spent taking care of humans on Earth. A poem by called "Whitey on the Moon" illustrated the  that was highlighted by the Space Race. The poem starts with:

Twenty percent of the world's population watched humans walk on the Moon for the first time. While Apollo 11 sparked the interest of the world, the follow-on Apollo missions did not hold the interest of the nation. One possible explanation was the shift in complexity. Landing someone on the Moon was an easy goal to understand; lunar geology was too abstract for the average person. Another is that Kennedy's goal of landing humans on the Moon had already been accomplished. A well-defined objective helped Project Apollo accomplish its goal, but after it was completed it was hard to justify continuing the lunar missions.

While most Americans were proud of their nation's achievements in space exploration, only once during the late 1960s did the indicate that a majority of Americans favored "doing more" in space as opposed to "doing less". By 1973, 59 percent of those polled favored cutting spending on space exploration. The Space Race had ended, and Cold War tensions were easing as the US and Soviet Union entered the era of. This was also a time when was rising, which put pressure on the government to reduce spending. What saved the space program was that it was one of the few government programs that had achieved something great. Drastic cuts, warned, the deputy director of the , might send a signal that "our best years are behind us".

After the Apollo 11 mission, officials from the Soviet Union said landing humans on the Moon was dangerous and unnecessary. At the time the Soviet Union was attempting to retrieve lunar samples robotically. The Soviets publicly denied there was a race to the Moon, and indicated they were not making an attempt. said in July 1969, "We are concentrating wholly on the creation of large satellite systems." It was revealed in 1989 that the Soviets had tried to send people to the Moon, but were unable due to technological difficulties. The public's reaction in the Soviet Union was mixed. The Soviet government limited the release of information about the lunar landing, which affected the reaction. A portion of the populace did not give it any attention, and another portion was angered by it.

The Apollo 11 landing is referenced in the songs "Armstrong, Aldrin and Collins" by on the 1969 album  and "Coon on the Moon" by  on the 1973 album The Back Door Wolf.

Spacecraft
The Command Module Columbia went on a tour of the United States, visiting 49 state capitals, the, and. In 1971, it was transferred to the, and was displayed at the (NASM) in Washington, DC. It was in the central Milestones of Flight exhibition hall in front of the Jefferson Drive entrance, sharing the main hall with other pioneering flight vehicles such as the ', ',, and .

Columbia was moved in 2017 to the NASM Mary Baker Engen Restoration Hangar at the in Chantilly, Virginia, to be readied for a four-city tour titled Destination Moon: The Apollo 11 Mission. This included from October 14, 2017 to March 18, 2018, the  from April 14 to September 3, 2018, the Senator John  in  from September 29, 2018 to February 18, 2019, and its last location at 's  from March 16 to September 2, 2019. Continued renovations at the Smithsonian allowed time for an additional stop for the capsule, and it was moved to the. The ribbon cutting ceremony was on September 29, 2019.

For 40 years Armstrong's and Aldrin's space suits were displayed in the museum's Apollo to the Moon exhibit, until it permanently closed on December 3, 2018, to be replaced by a new gallery which was scheduled to open in 2022. A special display of Armstrong's suit was unveiled for the 50th anniversary of Apollo 11 in July 2019. The quarantine trailer, the flotation collar and the flotation bags are in the Smithsonian's annex near  in Chantilly, Virginia, where they are on display along with a test lunar module.

The descent stage of the LM Eagle remains on the Moon. In 2009, the (LRO) imaged the various Apollo landing sites on the surface of the Moon, for the first time with sufficient resolution to see the descent stages of the lunar modules, scientific instruments, and foot trails made by the astronauts. The remains of the ascent stage lie at an unknown location on the lunar surface, after being abandoned and impacting the Moon. The location is uncertain because Eagle ascent stage was not tracked after it was jettisoned, and the lunar gravity field is sufficiently non-uniform to make the orbit of the spacecraft unpredictable after a short time.

In March 2012 a team of specialists financed by founder  located the  from the S-IC stage that launched Apollo 11 into space. They were found on the Atlantic seabed using advanced sonar scanning. His team brought parts of two of the five engines to the surface. In July 2013, a conservator discovered a serial number under the rust on one of the engines raised from the Atlantic, which NASA confirmed was from Apollo 11. The S-IVB third stage which performed Apollo 11's trans-lunar injection remains in a solar orbit near to that of Earth.

Moon rocks
The main repository for the Apollo Moon rocks is the at the Lyndon B. Johnson Space Center in. For safekeeping, there is also a smaller collection stored at near. Most of the rocks are stored in nitrogen to keep them free of moisture. They are handled only indirectly, using special tools. Over 100 research laboratories around the world conduct studies of the samples, and approximately 500 samples are prepared and sent to investigators every year.

In November 1969, Nixon asked NASA to make up about 250 presentation s for 135 nations, the fifty states of the United States and its possessions, and the United Nations. Each display included Moon dust from Apollo 11. The rice-sized particles were four small pieces of Moon soil weighing about 50 mg and were enveloped in a clear acrylic button about as big as a. This acrylic button magnified the grains of lunar dust. The Apollo 11 lunar sample displays were given out as goodwill gifts by Nixon in 1970.

Experiment results
The Passive Seismic Experiment ran until the command uplink failed on August 25, 1969. The downlink failed on December 14, 1969. , the remains operational.

Armstrong's camera
Armstrong's Hasselblad camera was thought to be lost or left on the Moon surface. In 2015, after Armstrong died in 2012, his widow contacted the to inform them she had found a white cloth bag in one of Armstrong's closets. The bag contained a forgotten camera that had been used to capture images of the first Moon landing. The camera is currently on display at the National Air and Space Museum.

40th anniversary events
On July 15, 2009, released a photo gallery of previously unpublished photos of the astronauts taken by Life photographer  prior to the Apollo 11 launch. From July 16 to 24, 2009, NASA streamed the original mission audio on its website in real time 40 years to the minute after the events occurred. It is in the process of restoring the video footage and has released a preview of key moments. In July 2010, air-to-ground voice recordings and film footage shot in Mission Control during the Apollo 11 powered descent and landing was re-synchronized and released for the first time. The set up an  website that rebroadcasts the transmissions of Apollo 11 from launch to landing on the Moon.

On July 20, 2009, Armstrong, Aldrin, and Collins met with U.S. President at the White House. "We expect that there is, as we speak, another generation of kids out there who are looking up at the sky and are going to be the next Armstrong, Collins, and Aldrin", Obama said. "We want to make sure that NASA is going to be there for them when they want to take their journey." On August 7, 2009, an act of Congress awarded the three astronauts a, the highest civilian award in the United States. The bill was sponsored by Florida Senator and Florida Representative.

A group of British scientists interviewed as part of the anniversary events reflected on the significance of the Moon landing: "It was carried out in a technically brilliant way with risks taken ... that would be inconceivable in the risk-averse world of today ... The Apollo programme is arguably the greatest technical achievement of mankind to date ... nothing since Apollo has come close [to] the excitement that was generated by those astronauts—Armstrong, Aldrin and the 10 others who followed them."

50th anniversary
On June 10, 2015, Congressman introduced resolution H.R. 2726 to the 114th session of the  directing the  to design and sell commemorative coins in gold, silver and clad for the 50th anniversary of the Apollo 11 mission. On January 24, 2019, the Mint released the to the public on its website.

A documentary film, , with restored footage of the 1969 event, premiered in on March 1, 2019, and broadly in theaters on March 8.

The Smithsonian Institute's and  sponsored the "Apollo 50 Festival" on the  in Washington DC. The three day (July 18 to 20, 2019) outdoor festival featured hands-on exhibits and activities, live performances, and speakers such as and NASA scientists.

As part of the festival, a projection of the 363 ft tall rocket was displayed on the east face of the 555 ft tall  from July 16 through the 20th from 9:30pm until 11:30pm (EDT). The program also included a 17-minute show that combined full-motion video projected on the Washington Monument to recreate the assembly and launch of the rocket. The projection was joined by a 40 ft wide recreation of the countdown clock and two large video screens showing archival footage to recreate the time leading up to the moon landing. There were three shows per night on July 19–20, with the last show on Saturday delayed slightly so the portion where Armstrong first set foot on the Moon would happen exactly 50 years to the second after the actual event.

On July 19, 2019, the paid tribute to the Apollo 11 Moon Landing, complete with a link to an animated  video with voiceover by astronaut.

Aldrin, Collins, and Armstrong's sons were hosted by President in the Oval Office.

Films and documentaries

 * , a 1969 documentary film by Bill Gibson and Barry Coe, about the Apollo 11 mission
 * , a 1971 documentary film by
 * Apollo 11: As it Happened, a 1994 six-hour documentary on ABC News' coverage of the event
 * , a 2019 documentary film by Todd Douglas Miller with restored footage of the 1969 event
 * , a July 2019 three-night six-hour documentary, directed by, examined the events leading up to the Apollo 11 mission. An accompanying book of the same name was also released.
 * 8 Days: To the Moon and Back, a and  2019 documentary film by Anthony Philipson re-enacting major portions of the Apollo 11 mission using mission audio recordings, new studio footage, NASA and news archives, and computer-generated imagery.