Moon landing culmination of years of work

0
1127
On Jan. 9, 1969, NASA announced the prime crew of the Apollo 11 lunar landing mission. This portrait was taken on Jan. 10, the day after the announcement of the crew assignment. Later that year in July 1969, the crew launched to the Moon and into history. From left to right are lunar module pilot Buzz Aldrin; commander Neil Armstrong; and command module pilot Michael Collins. They were photographed in front of a lunar module mockup beside Building 1 at what is now Johnson Space Center, following a press conference at the Center to introduce the crew. (NASA photograph)

In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union. On Oct. 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. This precipitated the Sputnik crisis, and triggered the Space Race. 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. It was another body blow to American pride. In spite of that, the Apollo program faced the opposition of many Americans and was dubbed “Moondoggle.” 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.

Kennedy believed that it was in the national interest of the United States to be superior to other nations, and that the perception of American power was at least as important as the actuality. It was therefore intolerable that the Soviet Union was more advanced in the field of space exploration. He was determined that the United States should compete, and sought a challenge that maximized its chances of winning. Since the Soviet Union had better booster rockets, he required a challenge that was beyond the capacity of the existing generation of rocketry, one where the United States and the Soviet Union would be starting from a position of equality. Something spectacular, even if it could not be justified on military, economic or scientific grounds. After consulting with his experts and advisers, he chose such a project. On May 25, 1961, he addressed the United States Congress on “Urgent National Needs” and declared:

The Apollo 11 crew leaves Kennedy Space Center’s Manned Spacecraft Operations Building during the pre-launch countdown. Mission commander Neil Armstrong, command module pilot Michael Collins, and lunar module pilot Buzz Aldrin prepare to ride the special transport van to Launch Complex 39A where their spacecraft awaited them. (NASA photograph)

“I believe that this nation should commit itself to achieving the goal, before this decade 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.”

The effort to land a man on the Moon already had a name: Project Apollo. 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 and that the Apollo spacecraft would have three major 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. This design meant that the spacecraft could be launched by a single Saturn V rocket that was then under development.

Technologies and technics required for Apollo were developed by Project Gemini. Project Apollo was temporarily halted by the Apollo 1 fire on Jan. 27, 1967, in which astronauts Gus Grissom, Ed White, and Roger B. Chaffee died, and the subsequent investigation. In October 1968, Apollo 7 evaluated the command module in Earth orbit, 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, 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.

The Apollo 11 Command and Service Modules (CSM) are photographed from the Lunar Module (LM) in lunar orbit during the Apollo 11 lunar landing mission. The lunar surface below is in the north central Sea of Fertility. (NASA photograph)

The Soviet Union competed with the United States in the Space Race, but its early lead was lost through repeated failures in development of the N1 launcher, which was comparable to the Saturn V. The Soviets tried to beat the U.S. 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 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.

Personnel
The initial crew assignment of Commander Neil Armstrong, Command Module Pilot Jim Lovell, and Lunar Module Pilot Buzz Aldrin on the backup crew for Apollo 9 was officially announced on Nov. 20, 1967. Lovell and Aldrin had previously flown together as the crew of Gemini 12. Due to design and manufacturing delays in the LM, Apollo 8 and Apollo 9 swapped prime and backup crews, and Armstrong’s crew became the backup for Apollo 8. Based on the normal crew rotation scheme, Armstrong was then expected to command Apollo 11.

There would be one change. Michael Collins, the CMP on the Apollo 8 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 Apollo 8 crew, and when Collins recovered he joined Armstrong’s crew as CMP. In the meantime, Fred Haise filled in as backup LMP, and Aldrin as backup CMP for Apollo 8. Apollo 11 was the second American mission where all the crewmembers had prior spaceflight experience, the first being Apollo 10. The next was STS-26 in 1988.

Fifty years ago on July 20, 1969, humanity stepped foot on another celestial body and into history. (NASA photograph)

Deke Slayton, director of flight crew operations, 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 Apollo 13).

The Apollo 11 prime crew had none of the close cheerful camaraderie that characterized that of Apollo 12. 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.”

The backup crew consisted of Jim Lovell as Commander, William Anders as CMP, and Fred Haise as LMP. Anders had flown with Lovell on Apollo 8. In early 1969, he accepted a job with the National Aeronautics and Space Council effective August 1969, and announced that he would retire as an astronaut at that time. Ken Mattingly 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 Apollo 13.

A close-up view of astronaut Buzz Aldrin’s bootprint in the lunar soil, photographed with the 70mm lunar surface camera during Apollo 11’s sojourn on the moon. (NASA photograph)

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 that 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, Ronald Evans and Bill Pogue.

Capsule communicators
The capsule communicator (CAPCOM) was an astronaut at the Mission Control Center in Houston, Texas, who was the only person who communicated directly with the flight crew. For Apollo 11, the CAPCOMs were: Charles Duke, Ronald Evans, Bruce McCandless II, James Lovell, William Anders, Ken Mattingly, Fred Haise, Don L. Lind, Owen K. Garriott and Harrison Schmitt.

Landing site selection
NASA’s Apollo Site Selection Board announced five potential landing sites on Feb. 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 Lunar Orbiter program and information about surface conditions provided by the Surveyor program.

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.

This July 20, 1969 photograph of the interior view of the Apollo 11 Lunar Module shows astronaut Edwin E. “Buzz” Aldrin during the lunar landing mission. (NASA photograph)

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: Sites 1 and 2 were in the Sea of Tranquility (Mare Tranquilitatis); Site 3 was in the Central Bay (Sinus Medii); and Sites 4 and 5 were in the Ocean of Storms (Oceanus Procellarum). The final site selection was based on seven criteria:

• The site needed to be smooth, with relatively few craters;
• 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;
• Provide 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;
• Good visibility during the landing approach, meaning that the Sun would be between 7 and 20 degrees behind the LM; and
• A general slope of less than 2 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 Site 2, with Sites 3 and 5 as backups in the event of the launch being delayed. In May 1969, Apollo 10’s lunar module flew to within 9.3 miles of Site 2, and reported that it was acceptable.

The Apollo 11 Lunar Module Eagle, in a landing configuration was photographed in lunar orbit from the Command and Service Module Columbia. Inside the module were Commander Neil A. Armstrong and Lunar Module Pilot Buzz Aldrin. The long rod-like protrusions under the landing pods are lunar surface sensing probes. Upon contact with the lunar surface, the probes sent a signal to the crew to shut down the descent engine. (NASA photograph)

First-step decision
During the first press conference after the Apollo 11 crew was announced, the first question a reporter asked was, “Which one of you gentlemen will be the first man to step onto the lunar surface?” Slayton told the reporter that 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 command module pilot, which matched what had been done in previous missions. The commander had never performed the spacewalk. Reporters wrote in early 1969 that Aldrin would be the first to walk on the Moon, and Associate Administrator George Mueller told reporters he would be the first as well. Aldrin heard that Armstrong would be the first to step on the Moon 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.”

Astronaut Edwin E. Aldrin Jr., lunar module pilot, egresses the Lunar Module “Eagle” and begins to descend the steps of the LM ladder as he prepares to walk on the moon. (NASA photograph)

The media accused Armstrong of exercising his commander’s prerogative to exit the spacecraft first. Chris Kraft revealed in his 2001 autobiography that a meeting occurred between Slayton, George Low, spacecraft program manager, Dr. Robert Gilruth, Marshall Space Center director, 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 Charles Lindbergh, 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 Kennedy Space Center on Jan. 8, 1969, followed by the descent stage four days later, and Command and Service Module CM-107 on Jan. 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 Early Apollo Scientific Experiments Package (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 Jan. 29, and moved from the Operations and Checkout Building to the Vehicle Assembly Building on April 14.

The S-IVB third stage of Saturn V AS-506 had arrived on Jan. 18, followed by the S-II second stage on Feb. 6, S-IC first stage on Feb. 20, and the Saturn V Instrument Unit on Feb. 27. At 12:30 on May 20, the 6,000-ton assembly departed the Vehicle Assembly Building atop the crawler-transporter, bound for Launch Pad 39A, part of Launch Complex 39, 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 mobile service structure 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 liquid hydrogen. Fueling was completed by three hours before launch. Launch operations were partly automated, with 43 programs written in the ATOLL programming language.

This view from the Apollo 11 spacecraft shows the Earth rising above the moon’s horizon. (NASA photograph)

Slayton roused the crew shortly after 4 a.m., 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 6:30 a.m., they headed out to Launch Complex 39. Backup crew member Fred Haise entered Columbia about three hours and 10 minutes before launch time. Along with a technician, he helped Armstrong into the left hand couch at 6:54 a.m. 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 10 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 20 seconds before launch time. More than 450 personnel were at the consoles in the firing room.

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 Chief of Staff of the United States Army, Gen. William Westmoreland, four cabinet members, 19 state governors, 40 mayors, 60 ambassadors and 200 congressmen. Vice President Spiro Agnew viewed the launch with former president, Lyndon B. Johnson and his wife Lady Bird Johnson. 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 Richard Nixon viewed the launch from his office in the White House with his NASA liaison officer, Apollo astronaut Frank Borman.

The historical plaque on the Apollo 11 lunar module Eagle with the inscription: “HERE MEN FROM THE PLANET EARTH FIRST SET FOOT UPON THE MOON JULY 1969, A. D. WE CAME IN PEACE FOR ALL MANKIND” The plaque is signed by the three crew members of Apollo 11 (Neil Armstrong, Michael Collins and Edwin E. Aldrin, Jr) and U.S. President Richard Nixon. (NASA photograph)

Saturn V AS-506 launched Apollo 11 on July 16, 1969, 9:32 a.m., EDT. At 13.2 seconds into the flight, the launch vehicle began to roll into its flight azimuth of 72.058 degrees. Full shutdown of the first-stage engines occurred at about 2 minutes 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 9 minutes and 8 seconds, allowing the first ignition of the S-IVB engine a few seconds later.

Apollo 11 entered Earth orbit at an altitude of 100.4 nautical miles by 98.9 nautical miles, 12 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 trans-lunar injection burn at 11:22 a.m. About 30 minutes later, with Collins in the left seat and at the controls, the transposition, docking, and extraction 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 slingshot effect from passing around the Moon threw it into an orbit around the Sun.

On July 19 at 12:21:50 p.m., Apollo 11 passed behind the Moon and fired its service propulsion engine to enter lunar orbit. In the 30 orbits that followed, the crew saw passing views of their landing site in the southern Sea of Tranquillity about 12 miles southwest of the crater Sabine D. The site was selected in part because it had been characterized as relatively flat and smooth by the automated Ranger 8 and Surveyor 5 landers and the Lunar Orbiter mapping spacecraft and unlikely to present major landing or EVA challenges. It lay about 16 miles southeast of the Surveyor 5 landing site, and 42 miles southwest of Ranger 8’s crash site.

Astronaut and Lunar Module pilot Buzz Aldrin is pictured during the Apollo 11 extravehicular activity on the moon. He had just deployed the Early Apollo Scientific Experiments Package. In the foreground is the Passive Seismic Experiment Package; beyond it is the Laser Ranging Retro-Reflector. (NASA photograph)

Lunar descent
At 7:52 a.m., on July 20, Aldrin and Armstrong entered Eagle, and began the final preparations for lunar descent. At 12:44 p.m., 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 that they were 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 mascons — 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 6,000 feet above the surface of the Moon, the LM guidance computer distracted the crew with the first of several unexpected 1201 and 1202 program alarms. Inside Mission Control Center, computer engineer Jack Garman told Guidance Officer Steve Bales 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 of its tasks in real time and had to postpone some of them. Margaret Hamilton, the Director of Apollo Flight Computer Programming at the MIT Charles Stark Draper Laboratory later recalled:

A photograph of Neil Armstrong taken by Buzz Aldrin. This is one of the few photographs of Armstrong on the lunar surface; most of the time he had the camera. (NASA photograph)

“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 Don Eyles 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 Apollo 5. Having the rendezvous radar on (so that 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 cycle stealing, 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-foot diameter crater (later determined to be West crater), 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 fast. Throughout the descent, Aldrin called out navigation data to Armstrong, who was busy piloting Eagle. Now 107 feet above the surface, Armstrong knew their propellant supply was dwindling and was determined to land at the first possible landing site.

Astronaut Edwin E. Aldrin Jr.,Lunar Module LM pilot, walks near the module as a picture is taken of him. Discoloration is visible on his boots and suit from the lunar soil adhering to them. Reflection of the LM and Astronaut Niel A. Armstrong is visible in Aldrin’s helmet visor. Image taken at Tranquility Base during the Apollo 11 Mission. (NASA photograph)

Armstrong found a clear patch of ground and maneuvered the spacecraft towards it. As he got closer, now 250 feet 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 feet from the surface, with only 90 seconds of propellant remaining. Lunar dust kicked up by the LM’s engine began to obfuscate 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 few moments before the landing, a light informed Aldrin that at least one of the 67-inch probes hanging from Eagle’s footpads had touched the surface, and he said: “Contact light!” Armstrong was supposed to immediately shutdown the engine, 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 shutdown the engine. Aldrin immediately said “Okay, engine stop. ACA — out of detent.” 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 attitude control assembly, the LM’s control stick. Output went to the LGC to command the reaction control system jets to fire. “Out of Detent” meant that 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 that the LM had landed.

Neil Armstrong works at the Lunar Module in the only photo taken of him on the moon from the surface. (NASA photograph)

Eagle landed at 3:17 p.m., on July 20 with 216 pounds of usable fuel remaining. Information available to the crew and mission controllers during the landing showed that 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, Tranquility Base 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 communion privately. At this time NASA was still fighting a lawsuit brought by atheist Madalyn Murray O’Hair (who had objected to the Apollo 8 crew reading from the Book of Genesis) 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 Webster Presbyterian Church, 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.

This photograph of the Lunar Module at Tranquility Base was taken by Neil Armstrong during the Apollo 11 mission, from the rim of Little West Crater on the lunar surface. Armstrong’s shadow and the shadow of the camera are visible in the foreground. This is the furthest distance from the lunar module traveled by either astronaut while on the moon. (NASA photograph)

The schedule for the mission called for the astronauts to follow the landing with a five-hour sleep period, but they chose to begin the preparations for the EVA early, thinking that they would be unable to sleep.

Lunar surface operations
Preparations for the EVA began at 6:43 p.m. 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. Once Armstrong and Aldrin were ready to go outside, Eagle was depressurized. The hatch was opened at 9:39 p.m. Armstrong initially had some difficulties squeezing through the hatch with his portable life support system. Some of the highest heart rates recorded from Apollo astronauts occurred during LM egress and ingress. At 9:51 p.m., Armstrong began his descent to the lunar surface. The remote control unit controls 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 folded against Eagle’s side and activate the TV camera.

Apollo 11 used slow-scan television 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 Goldstone Communications Complex in the United States, but with better fidelity by Honeysuckle Creek Tracking Station near Canberra in Australia. Minutes later, the feed was switched to the more sensitive Parkes radio telescope 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 recordings of the original slow scan source transmission from the lunar surface were likely destroyed during routine magnetic tape re-use at NASA.

Buzz Aldrin moves toward a position to deploy two components of the Early Apollo Scientific Experiments Package on the surface of the moon during the Apollo 11 mission. (NASA photograph)

While still on the ladder, Armstrong uncovered a plaque 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 Nixon administration to add a reference to God, NASA “shrewdly” included the vague date as a reason to include A.D., which stands for “in the year of our Lord”.

After describing the surface dust as “very fine-grained” and “almost like a powder,” at 9:56 p.m., six and a half hours after landing, Armstrong stepped off Eagle’s 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.

Buzz Aldrin moves toward a position to deploy two components of the Early Apollo Scientific Experiments Package on the surface of the moon during the Apollo 11 mission. (NASA photograph)

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 Hasselblad camera which could be operated hand held or mounted on Armstrong’s Apollo/Skylab A7L space suit. Aldrin joined Armstrong on the surface. He described the view with the simple phrase: “Magnificent desolation.”

Armstrong said that moving in the lunar gravity, 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’s 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.

Buzz Aldrin salutes the U.S flag on the Moon. His fingertips are visible on the far side of his faceplate. (NASA photograph)

The astronauts planted the Lunar Flag Assembly containing a flag of the United States 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 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.

“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 Tranquillity, it inspires us to redouble our efforts to bring peace and tranquillity 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,” said Nixon.

Armstrong replied, “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.”

On July 24, 1969, the Apollo 11 crew splashed down in the Pacific Ocean. The crew is awaiting pickup by a helicopter from the USS Hornet, prime recovery ship for the historic lunar landing mission. The fourth man in the life raft is a United States Navy underwater demolition team swimmer. All four men are wearing biological isolation garments. (NASA photograph)

They deployed the EASEP, which included a passive seismic experiment package used to measure moonquakes and a retroreflector array used for the lunar laser ranging experiment. Then Armstrong walked 196 feet from the LM to snap photos at the rim of Little West Crater while Aldrin collected two core samples. He used the geologist’s hammer to pound in the tubes — the only time the hammer was used on Apollo 11 ­— but was unable to penetrate more than 6 inches 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 13 pounds of soil into the box of rocks in order to pack them in tightly. Two types of rocks were found in the geological samples: basalt and breccia. Three new minerals were discovered in the rock samples collected by the astronauts: armalcolite, tranquillityite and pyroxferroite. Armalcolite was named after Armstrong, Aldrin, and Collins. All have subsequently been found on Earth.

Mission Control used a coded phrase to warn Armstrong that 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 47.5 pounds of lunar surface material to the LM hatch using a flat cable pulley device called the Lunar Equipment Conveyor. 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 life support, 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 5:11:13. They then pressurized the LM and settled down to sleep.

On July 24, 1969, the Apollo 11 crew splashed down in the Pacific Ocean. The three were quarantined after their return to earth. (NASA photograph)

Nixon’s speech writer William Safire had prepared “In Event of Moon Disaster” for the president to read on television in the event the Apollo 11 astronauts were stranded on the Moon.

The contingency plan originated in a memo from Safire to Nixon’s White House Chief of Staff H. R. Haldeman, 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 burial at sea. The last line of the prepared text contained an allusion to Rupert Brooke’s First World War poem, “The Soldier.”

While moving inside the cabin, Aldrin accidentally damaged the circuit breaker 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. However, 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 21.5 hours on the lunar surface, in addition to the scientific instruments, the astronauts left behind: an Apollo 1 mission patch in memory of astronauts Roger Chaffee, Gus Grissom and Edward White, who died when their command module caught fire during a test in January 1967; a memorial bag containing a gold replica of an olive branch as a traditional symbol of peace; and a silicon message disk carrying the goodwill statements 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 U.S. 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 12:54 p.m., they lifted off in Eagle’s 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 feet 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 attitude indicator, but I looked up long enough to see the flag fall over.” Subsequent Apollo missions usually planted the American flags further from the LM to prevent them being blown over by the ascent engine exhaust.

President Richard M. Nixon was in the central Pacific recovery area to welcome the Apollo 11 astronauts aboard the USS Hornet, prime recovery ship for the historic Apollo 11 lunar landing mission. Already confined to the Mobile Quarantine Facility (MQF) are (left to right) Neil A. Armstrong, commander; Michael Collins, command module pilot; and Edwin E. Aldrin Jr., lunar module pilot. (NASA photograph)

Columbia in lunar orbit
During his day flying solo around the Moon, Collins never felt lonely. Although it has been said “not since Adam 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 fuel cells 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 that 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 offending 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 certain contingencies in which he would fly Columbia down to meet Eagle.

Return
Eagle rendezvoused with Columbia at 4:24 p.m., CDT, on July 21, and the two docked at 4:35 p.m. Eagle’s ascent stage was jettisoned into lunar orbit at 4:41 p.m. Just before the Apollo 12 flight, it was noted that Eagle was still likely to be orbiting the Moon. Later NASA reports mentioned that Eagle’s 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 EMU, 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 aircraft carrier USS Hornet, under the command of Capt. Carl J. Seiberlich, was selected as the primary recovery ship for Apollo 11 on June 5, replacing its sister ship, the LPH USS Princeton, which had recovered Apollo 10 on May 26. Hornet was then at her home port of Long Beach, Calif. On reaching Pearl Harbor on July 5, Hornet embarked the Sikorsky SH-3 Sea King helicopters of HS-4, a unit which specialized in recovery of Apollo spacecraft, specialized divers of UDT 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 boilerplate 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.

A presidential party consisting of Nixon, Borman, Secretary of State William P. Rogers and National Security Adviser Henry Kissinger flew to Johnston Atoll on Air Force One, then to the command ship USS Arlington in Marine One. 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 Commander-in-Chief, Pacific Command, Adm. John S. McCain Jr., and NASA Administrator Thomas O. Paine, who flew to Hornet from Pago Pago in one of Hornet’s carrier onboard delivery aircraft.

Weather satellites were not yet common, but U.S. Air Force Capt. 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 was a serious threat to the mission; if the helicopters could not locate Columbia, the spacecraft, its crew, and its priceless cargo of Moon rocks might be lost. Brandli alerted Navy Capt. Willard S. Houston Jr., the commander of the Fleet Weather Center at Pearl Harbor, who had the required security clearance. On their recommendation, Rear Adm. Donald C. Davis, the commander of Manned Spaceflight Recovery Forces, Pacific, advised NASA to change the recovery area. This was done; a new one was designated, 215 nautical miles northeast of the original.

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 that 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 standard gravities; the second, to 6.0 standard gravities.

Before dawn on July 24, Hornet launched four Sea King helicopters and three Grumman E-1 Tracers. 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 11:44 a.m., CDT, Columbia’s drogue parachutes were deployed. This was observed by the helicopters. Seven minutes later Columbia struck the water forcefully 1,440 nautical miles east of Wake Island, 210 nautical miles south of Johnston Atoll, and 13 nautical miles from Hornet.

During splashdown, Columbia landed upside down but was righted within 10 minutes by flotation bags activated by the astronauts. A diver from the Navy helicopter hovering above attached a sea anchor 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 to the astronauts, and assisted them into the life raft. The possibility of bringing back pathogens from the lunar surface was considered remote, but NASA took precautions at the recovery site. The astronauts were rubbed down with a sodium hypochlorite solution and Columbia wiped with Betadine 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 12:53 p.m., CDT, the helicopter was lowered by the elevator into the hangar bay, where the astronauts walked the 30 feet to the Mobile Quarantine Facility, 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 Apollo 14, 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 4.5-ton Columbia, which was lifted aboard by the ship’s crane, placed on a dolly 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 Lockheed C-141 Starlifter and airlifted to the Manned Spacecraft Center. The astronauts arrived at the Lunar Receiving Laboratory on July 28. Columbia was taken to Ford Island for deactivation, and its pyrotechnics made safe. It was then taken to Hickham Air Force Base, Hawaii, from whence it was flown to Houston in a Douglas C-133 Cargomaster, reaching the Lunar Receiving Laboratory on July 30.

In accordance with the Extra-Terrestrial Exposure Law, 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 Aug. 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 William Carpentier and MQF project engineer John Hirasaki), and on Columbia itself. Loose equipment from the spacecraft remained in isolation until the lunar samples were released for study.

Celebrations
On Aug. 13, the three astronauts rode in ticker-tape parades 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 state dinner to celebrate the flight, attended by members of Congress, 44 governors, the Chief Justice of the United States, and ambassadors from 83 nations at the Century Plaza Hotel. Nixon and Agnew honored each astronaut with a presentation of the Presidential Medal of Freedom.

The three astronauts spoke before a joint session of Congress on Sept. 16, 1969. They presented two U.S. flags, one to the House of Representatives and the other to the Senate, that had been carried to the surface of the Moon with them. The flag of American Samoa on Apollo 11 is on display at the Jean P. Haydon Museum in Pago Pago, the capital of American Samoa.

This celebration was the beginning of 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 Sept. 29 to Nov. 5. Many nations honored the first human Moon landing with special features in magazines or by issuing Apollo 11 commemorative postage stamps or coins.

Legacy
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 over other nations. 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 famous words on the lunar surface also spun off countless parodies.

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 Gallup Poll 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 U.S. and Soviet Union entered the era of détente. This was also a time when inflation 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 Caspar Weinberger, the deputy director of the Office of Management and Budget, might send a signal that “our best years are behind us.”

After the Apollo 11 mission, officials from the Soviet Union said that 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 that they were not making an attempt. Mstislav Keldysh said in July 1969 that, “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 to 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.

Spacecraft
The Command Module Columbia went on a tour of the United States, visiting 49 state capitals, the District of Columbia, and Anchorage Alaska. In 1971, it was transferred to the Smithsonian Institution, and was displayed at the National Air and Space Museum in Washington, D.C. 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 Wright Flyer, Spirit of St. Louis, Bell X-1, North American X-15 and Friendship 7.

Columbia was moved in 2017 to the NASM Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center in Chantilly, Va., to be readied for a four-city tour titled Destination Moon: The Apollo 11 Mission. This included Space Center Houston from Oct. 14, 2017 to March 18, 2018, the Saint Louis Science Center from April 14 to Sept. 3, 2018, the Senator John Heinz History Center in Pittsburgh from Sept. 29, 2018, to Feb. 18, 2019, and its current location at the Seattle Museum of Flight from March 16 to Sept. 2, 2019.

For 40 years Armstrong’s and Aldrin’s space suits were displayed in the museum’s Apollo to the Moon exhibit, until it closed for good on Dec. 3, 2018, to be replaced by a new gallery which was scheduled to open in 2022. A special display of Armstrong’s suit is planned 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 Steven F. Udvar-Hazy Center annex near Washington Dulles International Airport in Chantilly, Va., 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 Lunar Reconnaissance Orbiter 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 Amazon founder Jeff Bezos located the F-1 engines 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 Lunar Sample Laboratory Facility at the Lyndon B. Johnson Space Center in Houston, Texas.

For safekeeping, there is also a smaller collection stored at White Sands Test Facility near Las Cruces, N.M. Most of the rocks are stored in nitrogen to keep them free of moisture. They are handled only indirectly, using special tools. More than 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 Apollo 11 lunar sample displays for 135 nations, the 50 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 United States half dollar coin. 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.

The Passive Seismic Experiment ran until the command uplink failed on Aug. 25, 1969. The downlink failed on Dec. 14, 1969. As of 2018, the Lunar Laser Ranging experiment remains operational.

On Aug. 7, 2009, as part of the 40th anniversary celebration, an act of Congress awarded the three astronauts a Congressional Gold Medal, the highest civilian award in the United States. The bill was sponsored by Florida Senator Bill Nelson and Florida Representative Alan Grayson.

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 program 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 events
On June 10, 2015, Congressman Bill Posey introduced resolution H.R. 2726 to the 114th session of the United States House of Representatives directing the United States Mint to design and sell commemorative coins in gold, silver and clad for the 50th anniversary of the Apollo 11 mission. On Jan. 24, 2019, the Mint released the Apollo 11 50th Anniversary commemorative coins to the public on its website.

A documentary film, “Apollo 11,” with restored footage of the 1969 event, premiered in IMAX on March 1, 2019, and broadly in theaters on March 8.

Beginning on July 9, 2019, PBS aired a three-night, six-hour documentary, called “Chasing the Moon,” which examined the events leading up to Apollo 11. An accompanying book of the same name was also released.

Additionally, there are numerous events and television specials around the country.