Apollo program

Apollo program insignia

Apollo 17 astronaut Harrison Schmitt standing next to a boulder at Taurus-Littrow on the Moon in December 1972.

The Apollo program was an American spaceflight endeavor that landed the first humans on Earth's Moon. Conceived during the presidency of Dwight D. Eisenhower and conducted by NASA, Apollo began in earnest after President John F. Kennedy's May 25, 1961 special address to a joint session of Congress declaring a national goal of "landing a man on the Moon" by the end of the decade.

This goal was accomplished with the Apollo 11 mission on July 20, 1969 when astronauts Neil Armstrong and Buzz Aldrin landed on the Moon, while Michael Collins remained in lunar orbit. Five subsequent Apollo missions also landed astronauts on the Moon, the last in December 1972. In these six Apollo spaceflights, 12 men walked on the Moon. These are the only times humans have landed on another celestial body.

The Apollo program ran from 1961 until 1975, and was the US civilian space agency's third human spaceflight program (following Mercury and Gemini). Apollo used Apollo spacecraft and Saturn launch vehicles, which were later used for the Skylab program and the joint American-Soviet Apollo-Soyuz Test Project. These subsequent programs are thus often considered part of the Apollo program.

The program was accomplished with only two major setbacks: The first was the Apollo 1 launchpad fire that resulted in the deaths of astronauts Gus Grissom, Ed White and Roger Chaffee; the second was an oxygen tank rupture on Apollo 13 during the moonward phase of its journey, which disabled the command spacecraft. Using the lunar module as a "lifeboat", the three astronauts aboard narrowly escaped with their lives, thanks to the efforts of flight controllers, project engineers, backup crew members and the skills of the astronauts.

Apollo set major milestones in human spaceflight. It stands alone in sending manned missions beyond low Earth orbit; Apollo 8 was the first manned spacecraft to orbit another celestial body, while Apollo 17 marked the last moonwalk and the last manned mission beyond low Earth orbit. The program spurred advances in many areas of technology incidental to rocketry and manned spaceflight, including avionics, telecommunications, and computers. Apollo sparked interest in many fields of engineering and left many physical facilities and machines developed for the program as landmarks. Many objects and artifacts from the program are on display at locations throughout the world, notably in the Smithsonian's Air and Space Museums.

Background

Main article: Space Race

The Apollo program was conceived early in 1960, during the Eisenhower administration, as a follow-up to America's Mercury program. While the Mercury capsule could only support one astronaut on a limited earth orbital mission, the Apollo spacecraft was to be able to carry three astronauts on a circumlunar flight and perhaps even on a lunar landing. The program was named after the Greek god of light and music by NASA manager Abe Silverstein, who later said that "I was naming the spacecraft like I'd name my baby." While NASA went ahead with planning for Apollo, funding for the program was far from certain given Eisenhower's ambivalent attitude to manned spaceflight.

May 25, 1961: President John F. Kennedy addresses a Joint Session of Congress and lays out his plan to put a man on the moon and return him safely to Earth.

In November 1960, John F. Kennedy was elected President after a campaign that promised American superiority over the Soviet Union in the fields of space exploration and missile defense. Using space exploration as a symbol of national prestige, he warned of a "missile gap" between the two nations, pledging to make the U.S. not "first but, first and, first if, but first period." Despite Kennedy's rhetoric, he did not immediately come to a decision on the status of the Apollo program once he was elected President. He knew little about the technical details of the space program, and was put off by the massive financial commitment required by a manned moon landing. When NASA Administrator James Webb requested a 30 percent budget increase for his agency, Kennedy supported an acceleration of NASA's large booster program but deferred a decision on the broader issue.

President John F. Kennedy delivers a speech at Rice University on the subject of the American space program, September 12, 1962.

On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person to fly in space, reinforcing American fears about being left behind in a technological competition with the Soviet Union. At a meeting of the U.S. House Committee on Science and Astronautics held only one day after Gagarin's flight, many congressmen pledged their support for a crash program aimed at ensuring that America would catch up. Kennedy, however, was circumspect in his response to the news, refusing to make a commitment on America's response to the Soviets. On April 20 Kennedy sent a memo to Vice President Lyndon B. Johnson, asking Johnson to look into the status of America's space program, and into programs that could offer NASA the opportunity to catch up. Johnson responded approximately one week later, concluding that "we are neither making maximum effort nor achieving results necessary if this country is to reach a position of leadership." His memo concluded that a manned moon landing was far enough in the future that it was likely the United States would achieve it first.

On May 25, 1961, Kennedy announced his support for the Apollo program as part of a special address to a joint session of Congress:

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 in the long-range exploration of space; and none will be so difficult or expensive to accomplish.

— John F. Kennedy

At the time of Kennedy's speech, only one American had flown in space—less than a month earlier—and NASA had not yet sent a man into orbit. Even some NASA employees doubted whether Kennedy's ambitious goal could be met.

Answering President Kennedy's challenge and landing men on the moon by the end of 1969 required the most sudden burst of technological creativity, and the largest commitment of resources ($24 billion), ever made by any nation in peacetime. At its peak, the Apollo program employed 400,000 people and required the support of over 20,000 industrial firms and universities.

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 which we intend to win, and the others, too... Many years ago the great British explorer George Mallory, who was to die on Mount Everest, was asked why did he want to climb it. He said, "Because it is there." Well, space is there, and we're going to climb it, and the moon and the planets are there, and new hopes for knowledge and peace are there. And, therefore, as we set sail we ask God's blessing on the most hazardous and dangerous and greatest adventure on which man has ever embarked.

— John F. Kennedy

Choosing a mission mode

See also: Moon landing

Once Kennedy had defined a goal, the Apollo mission planners were faced with the challenge of designing a set of flights that could meet this stated goal while minimizing risk to human life, cost, and demands on technology and astronaut skill. Four possible mission modes were considered:

Early Apollo configuration for
Direct Ascent and
Earth Orbit Rendezvous - 1961 (NASA)

• Direct Ascent: A spacecraft would travel directly to the Moon, landing and returning as a unit. This plan would have required a more powerful booster, the planned Nova rocket.
• Earth Orbit Rendezvous (EOR): Multiple rockets (up to fifteen in some claims) would be launched, each carrying various parts of a Direct Ascent spacecraft and propulsion units that would have enabled the spacecraft to escape earth orbit. After a docking in earth orbit, the spacecraft would have landed on the Moon as a unit.
• Lunar Surface Rendezvous: Two spacecraft would be launched in succession. The first, an automated vehicle carrying propellants, would land on the Moon and would be followed some time later by the manned vehicle. Propellant would be transferred from the automated vehicle to the manned vehicle before the manned vehicle could return to Earth.
• Lunar Orbit Rendezvous (LOR): One Saturn V would launch a spacecraft that was composed of modular parts. A command ship would remain in orbit around the moon, while a Lunar Excursion Module would descend to the moon and then return to dock with the command ship while still in lunar orbit. In contrast with the other plans, LOR required only a small part of the spacecraft to land on the Moon, thereby minimizing the mass to be launched from the Moon's surface for the return trip.

In early 1961, direct ascent was generally the mission mode in favor at NASA. Many engineers feared that a rendezvous —let alone a docking— neither of which had been attempted even in Earth orbit, would be extremely difficult in lunar orbit. However, dissenters including John Houbolt at Langley Research Center emphasized the important weight reductions that were offered by the LOR approach. Throughout 1960 and 1961, Houbolt campaigned for the recognition of LOR as a viable and practical option. Bypassing the NASA hierarchy, he sent a series of memos and reports on the issue to Associate Administrator Robert Seamans; while acknowledging that he spoke "somewhat as a voice in the wilderness," Houbolt pleaded that LOR should not be discounted in studies of the question.

Seamans' establishment of the Golovin committee in July 1961 represented a turning point in NASA's mission mode decision. While the ad-hoc committee was intended to provide a recommendation on the boosters to be used in the Apollo program, it recognized that the mode decision was an important part of this question. The committee recommended in favor of a hybrid EOR-LOR mode, but its consideration of LOR —as well as Houbolt's ceaseless work— played an important role in publicizing the workability of the approach. In late 1961 and early 1962, members of NASA's Space Task Group at the Manned Spacecraft Center in Houston began to come around to support for LOR. The engineers at Marshall Space Flight Center took longer to become convinced of its merits, but their conversion was announced by Wernher von Braun at a briefing in June 1962. NASA's formal decision in favor of LOR was announced on July 11, 1962. Space historian James Hansen concludes that:

Without NASA's adoption of this stubbornly held minority opinion in 1962, the United States may still have reached the Moon, but almost certainly it would not have been accomplished by the end of the 1960s, President Kennedy's target date.

— James Hansen

The LOR method had the advantage of allowing the lander spacecraft to be used as a "life boat" in the event of a failure of the command ship. This happened on Apollo 13 when an oxygen tank failure left the command ship without electrical power. The Lunar Module provided propulsion, electrical power and life support to get the crew home safely.

Spacecraft

Main article: Apollo spacecraft

The decision in favor of lunar orbit rendezvous dictated the basic design of the Apollo spacecraft. It would consist of two main sections: the Command/Service Module (CSM), in which the crew would spend most of the mission, and the Lunar Module (LM), which would descend to and return from the lunar surface.

Command/Service Module

Main article: Apollo Command/Service Module

Apollo CSM in lunar orbit

The Command Module (CM) was the crew cabin, surrounded by a conical re-entry heat shield, designed to carry three astronauts from launch to lunar orbit and back to an Earth ocean splashdown. As such, it was the only component of the Apollo spacecraft to survive without major configuration changes as the program evolved from the early Apollo study designs. Equipment carried by the Command Module included reaction control engines, a docking tunnel, guidance and navigation systems and the Apollo Guidance Computer.

Attached to the Command Module was the cyllindrical Service Module (SM), which housed the service propulsion system and its propellants, the fuel cell power system, four maneuvering thruster quads, a high-gain S-band antenna for communications between the Moon and Earth, and storage tanks for water and oxygen. On the last three lunar missions, it also carried a scientific instrument package.

As the program concept evolved, use of the term "module" changed from its true meaning of an interchangeable component of systems with multiple variants, to simply a component of the complete lunar landing system. The original pre-1961 studies contemplated a single Command Module with different sized Service Modules for various missions such as an earth-orbit shuttle to a space station, a ferry to lunar orbit, or return to Earth from a lunar landing (which would require an even larger descent stage attached to the SM.)

As used in the actual lunar program, the two modules remained attached throughout most of the flight to make a single ferry craft, somewhat awkwardly known as the Command/Service Module (CSM) which carried a separate lunar lander (only half as heavy as the CSM) to the Moon, and the astronauts home to Earth. Just before re-entry, the Service Module was discarded and only the Command Module re-entered the atmosphere, using its heat shield to survive the intense heat caused by air friction. After re-entry it deployed parachutes that slowed its descent, allowing a smooth splashdown in the ocean.

Under the leadership of Harrison Storms, North American Aviation won the contract to build the CSM, and also the second stage of the Saturn V launch vehicle for NASA. Relations between North American and NASA were strained during the winter of 1965-66 by delivery delays, quality shortfalls, and cost overruns in both components. They were strained even more a year later when a cabin fire killed the crew of Apollo 1 during a ground test. The cause was determined to be an electrical short in the wiring of the Command Module; while the determination of responsibility for the accident was complex, the review board concluded that "deficiencies existed in Command Module design, workmanship and quality control."

Lunar Module

Main article: Apollo Lunar Module

Apollo LM on lunar surface

The Lunar Module (LM) (originally known as the Lunar Excursion Module, LEM), was designed solely to land two astronauts on the Moon, and to take them back from the lunar surface to the Command Module. It had no aerodynamic heat shield and was of a construction so lightweight that it would not have been able to fly in Earth gravity. It consisted of two stages, a descent and an ascent stage. The descent stage incorporated compartments in which cargo such as the Apollo Lunar Surface Experiment Package and Lunar Rover could be carried.

The contract for design and construction of the Lunar Module was awarded to Grumman Aircraft Engineering Corporation, and the project was overseen by Tom Kelly. There were also problems with the Lunar Module; due to delays in the test program, the LM became a "pacing item," meaning that it was in danger of delaying the schedule of the whole Apollo program. Because of these issues, the Apollo missions were rescheduled so that the first manned mission with the Lunar Module would be Apollo 9, rather than Apollo 8 as was originally planned.

Launch vehicles

When the team of engineers led by Wernher von Braun began planning for the Apollo program, it was not yet clear what mission their rockets would have to support. Direct ascent would require a more powerful launch vehicle, the planned Nova, which could carry a very large payload to the Moon. NASA's decision in favor of Lunar Orbit Rendezvous re-oriented the work of the Marshall Space Flight Center towards the development of the Saturn 1B and Saturn V. While the Saturn V was not as powerful than the Nova would have been, it was still much more powerful than any rocket developed before, or since.

The Saturn IB rocket launched Apollo 7 and her crew into Earth orbit, October 11, 1968.

Saturn IB

Main article: Saturn IB

The Saturn IB was an upgraded version of the earlier Saturn I rocket, which was used in early Apollo boilerplate launches. It consisted of:

• An S-IB first stage powered by eight H-1 engines burning RP-1 with LOX oxidizer, to produce 1,600,000 pounds () of thrust;
• An S-IVB-200 second stage, powered by one J-2 engine burning liquid hydrogen with LOX oxidizer, to produce 225,000 pounds () of thrust; and
• An Instrument Unit which contained the rocket's guidance system.

The Saturn IB was capable of putting a partially-fueled Command/Service Module, or a Lunar Module, into earth orbit. It was used in five of the Apollo test missions including the first manned mission, and in the manned missions for the Skylab program and the Apollo-Soyuz Test Project.

Saturn V

Main article: Saturn V

The Saturn V was a three-stage rocket consisting of:

• An S-IC first stage, powered by five F-1 engines arranged in a cross pattern, burning RP-1 with LOX oxidizer to produce 7,500,000 pounds () of thrust. They burned for 2.5 minutes, accelerating the spacecraft to a speed of approximately 6,000 miles per hour (2.68 km/s).

The Saturn V rocket launched Apollo 11 and her crew on its journey to the Moon, July 16, 1969.

• An S-II second stage, powered by five of the J-2 engines used in the S-IVB. They burned for approximately six minutes, taking the spacecraft to a speed of 15,300 miles per hour (6.84 km/s) and an altitude of about 115 miles (185 km).
• An S-IVB-5200 third stage similar to the Saturn IB's second stage, with capability to restart the J-2 engine. The engine would burn for approximately two and a half minutes and shut down when a low-Earth parking orbit was achieved. After approximately two orbits to confirm the spacecraft was ready to commit to the lunar trip, the engine was restarted to make the translunar injection maneuver taking the spacecraft into an extremely high orbit where it would be captured by the Moon's gravity.
• An Instrument Unit with a guidance system similar to that used on the S-IB.

The first three Saturn V's did not fly to the moon, but were used for low-Earth orbit tests of the Apollo spacecraft. In 1973, a refitted S-IVB-500 stage, launched unmanned by the first two stages of the last Saturn V to fly, became the Skylab space station.

Astronauts

The following astronauts flew on the 11 manned Apollo missions, plus the Apollo 1 crew who were killed in a ground test one month before they were to have flown the first manned mission. Not included are the astronauts who subsequently flew on the Skylab (Apollo Applications Program) or Apollo-Soyuz Test Project missions which used the Apollo CSM.

From Astronaut Group 1
Astronaut	Service	Mission	Mercury/Gemini Flights
Virgil "Gus" Grissom	USAF	Apollo 1 Command Pilot	Mercury-Redstone 4, Gemini 3
Walter M. Schirra	USN	Apollo 7 CDR	Mercury-Atlas 8, Gemini 6A
Alan Shepard	USAF	Apollo 14 CDR	Mercury-Redstone 3
From Astronaut Group 2
Astronaut	Service	Mission	Mercury/Gemini Flights
Neil A. Armstrong	Civilian	Apollo 11 CDR	Gemini 8
Frank Borman	USAF	Apollo 8 CDR	Gemini 7
Charles "Pete" Conrad	USN	Apollo 12 CDR	Gemini 11
James A. Lovell	USN	Apollo 8 CMP, Apollo 13 CDR	Gemini 7, Gemini 12
James A. McDivitt	USAF	Apollo 9 CDR	Gemini 4
Thomas P. Stafford	USAF	Apollo 10 CDR	Gemini 6A, Gemini 9A
Edward H. White II	USAF	Apollo 1 Senior Pilot	Gemini 4
John W. Young	USN	Apollo 10 CMP, Apollo 16 CDR	Gemini 3, Gemini 10
From Astronaut Group 3
Astronaut	Service	Mission	Mercury/Gemini Flights
Edwin "Buzz" Aldrin	USAF	Apollo 11 LMP	Gemini 12
William A. Anders	USAF	Apollo 8 LMP
Alan L. Bean	USN	Apollo 12 LMP
Eugene A. Cernan	USN	Apollo 10 LMP, Apollo 17 CDR	Gemini 9A
Roger B. Chaffee	USN	Apollo 1 Pilot
Michael Collins	USAF	Apollo 11 CMP	Gemini 10
R. Walter Cunningham	ex-USMC	Apollo 7 LMP
Donn F. Eisele	USAF	Apollo 7 CMP
Richard F. Gordon, Jr.	USN	Apollo 12 CMP	Gemini 11
Russell L. "Rusty" Schweickart	ex-USAF	Apollo 9 LMP
David R. Scott	USAF	Apollo 9 CMP, Apollo 15 CDR	Gemini 8
From Astronaut Group 4
Astronaut	Service	Mission
Harrison H. Schmitt	Geologist	Apollo 17 LMP
From Astronaut Group 5
Astronaut	Service	Mission
Charles M. Duke	USAF	Apollo 16 LMP
Ronald E. Evans	USAF	Apollo 17 CMP
Fred W. Haise	ex-USMC	Apollo 13 LMP
James B. Irwin	USAF	Apollo 15 LMP
T. Kenneth Mattingly	USN	Apollo 16 CMP
Edgar D. Mitchell	USN	Apollo 14 LMP
Stuart A. Roosa	USAF	Apollo 14 CMP
John L. Swigert	ex-USAF	Apollo 13 CMP
Alfred M. Worden	USAF	Apollo 15 CMP

Missions

See also: List of Apollo missions

Mission types

In September 1967, the Manned Spacecraft Center in Houston, Texas, proposed a series of missions that would lead up to a manned lunar landing. Seven mission types were outlined, each testing a set of components and tasks; each previous step needed to be completed successfully before the next mission type could be undertaken. These were:

• A - Unmanned Command/Service Module (CSM) test
• B - Unmanned Lunar Module (LM) test
• C - Manned CSM in low Earth orbit
• D - Manned CSM and LM in low Earth orbit
• E - Manned CSM and LM in an elliptical Earth orbit with an apogee of 4600 mi (7400 km)
• F - Manned CSM and LM in lunar orbit
• G - Manned lunar landing

Later added to this were H missions, which were short duration stays on the Moon with two lunar EVAs ("moonwalks"). These were followed by the J missions, which were longer three day stays, with three LEVAs, using the lunar rover. Apollo 18 to 20 would have been J missions, as Apollo 15 to 17 were.

Another group of flights — the I missions — were planned, which would have been long duration orbital missions using a Scientific Instrument Module (SIM) which included a panoramic camera, gamma ray spectrometer, mapping camera, laser altimeter, mass spectrometer, and lunar sub-satellite. When it became obvious that later flights were being cancelled, this was incorporated into the J missions and operated by the Command Module Pilot during the lunar surface operations. After trans-earth injection, the CMP had to perform an EVA to retrieve the film.

Unmanned missions

Preparations for the Apollo program began long before the manned Apollo missions were flown. Test flights of the Saturn I booster began in October 1961 and lasted until September 1964. Three further Saturn I launches carried boilerplate models of the Apollo command/service module. Two pad abort tests of the launch escape system took place in 1963 and 1965 at the White Sands Missile Range. Three unmanned tests of Apollo components with the Saturn IB (Apollo-Saturn, or AS) were officially designated AS-201, AS-202, and AS-203.

The only unmanned missions to include "Apollo", rather than their serial number, as part of their name were Apollo 4, Apollo 5 and Apollo 6. The simple numbering was started at "4" due to the previous 3 Apollo-Saturn flights using the Saturn IB. Apollo 4 was the first test flight of the Saturn V booster. Launched on November 9, 1967, Apollo 4 exemplified George Mueller's strategy of "all up" testing. Rather than being tested stage by stage, as most rockets were, the Saturn V would be flown for the first time as one unit. The mission was a highly successful one. Walter Cronkite covered the launch from a broadcast booth about 4 miles (6 km) from the launch site. The extreme noise and vibrations from the launch nearly shook the broadcast booth apart- ceiling tiles fell and windows shook. At one point, Cronkite was forced to dampen the booth's plate glass window to prevent it from shattering. This launch showed that additional protective measures were necessary to protect structures in the immediate vicinity. Future launches used a damping mechanism directly at the launchpad which proved effective in limiting the generated noise.

Apollo 5 was a Saturn IB flight which tested a legless, windowless version of the lunar module (LM) in Earth orbit (no Command and Service Module (CSM) was included). Apollo 6, a second Saturn V launch with a CSM but no LM, was the last in the series of unmanned Apollo missions. It was launched on April 4, 1968, and landed back on Earth almost ten hours later at 21:57:21 UTC.

Manned missions

Apollo 11 astronaut Buzz Aldrin with the U.S. flag

On each manned mission there were three astronauts: a commander, a command module pilot (CMP), and a lunar module pilot (LMP). During a moon landing, the commander and the LMP descended to the Moon, while the CMP remained in lunar orbit.

Apollo 7, launched on October 11, 1968, was the first manned mission in the Apollo program. It was an eleven-day Earth-orbital mission intended to test the redesigned command module. It was the first manned launch of the Saturn IB launch vehicle, and the first three-man American space mission.

A mounted camera captures Neil Armstrong as he becomes the first human to step on the moon.

By the summer of 1968 it became clear to program managers that a fully functional LM would not be available for the Apollo 8 mission. Rather than perform a simple earth orbiting mission, they chose to send Apollo 8 around the moon during Christmas. The original idea for this switch was the brainchild of George Low. Although it has often been claimed that this change was made as a direct response to Soviet attempts to fly a piloted Zond spacecraft around the moon, there is no evidence that this was the case. NASA officials were aware of the Soviet Zond flights, but the timing of the Zond missions does not correspond well with the extensive written record from NASA about the Apollo 8 decision. The Apollo 8 decision was primarily based upon the LM schedule, not fear of the Soviets beating the Americans to the moon.

Between December 21, 1968 and May 18, 1969, NASA launched three Apollo missions (8, 9, and 10) using the Saturn V launch vehicle. Each mission had a crew of three astronauts, and the last two included Lunar Modules, but none of these were intended as Moon landing missions.

That's one small step for [a] man, one giant leap for mankind.

— Neil Armstrong

Astronaut Harrison H. Schmitt on December 13, 1972, during the Apollo 17 mission, the last human lunar landing to date.

The next two flights (11 and 12) included successful Moon landings. The Apollo 13 mission was aborted before the landing attempt, but the crew returned safely to Earth. The four subsequent Apollo missions (14 through 17) included successful Moon landings. The last three of these were J-class missions that included the use of Lunar Rovers.

Apollo 17, launched December 7, 1972, was the last Apollo mission to the moon. Mission commander Eugene Cernan was the last person to leave the Moon's surface. The crew returned safely to Earth on December 19, 1972.

Apollo applications program

Main article: Apollo Applications Program

Following the success of the Apollo program, both NASA and its major contractors investigated several post-lunar applications for the Apollo hardware. The "Apollo Extension Series", later called the "Apollo Applications Program", proposed up to thirty flights to earth orbit. Many of these would use the space that the lunar module took up in the Saturn rocket to carry scientific equipment.

Of all the plans, only two were implemented: the Skylab space station (May 1973 – February 1974), and the Apollo-Soyuz Test Project (July 1975). Skylab's fuselage was constructed from the second stage of a Saturn IB, and the station was equipped with the Apollo Telescope Mount, itself based on a lunar module. The station's three crews were ferried into orbit atop Saturn IBs, riding in CSMs; the station itself had been launched with a modified Saturn V. Skylab's last crew departed the station on February 8, 1974, while the station itself returned prematurely to Earth in 1979, by which time it had become the oldest operational Apollo component.

The Apollo-Soyuz Test Project involved a docking in Earth orbit between a CSM and a Soviet Soyuz spacecraft. The mission lasted from July 15 to July 24, 1975. Although the Soviet Union continued to operate the Soyuz and Salyut space vehicles, NASA's next manned mission would not be until STS-1 on April 12, 1981.

Summary of missions

U.S. Mission	Booster	Crew	Launched	Mission Goal	Mission Result
AS-201	Saturn 1B	Unmanned	February 26, 1966	Suborbital	Partial Success - Unmanned suborbital flight was the first test flight of Saturn 1B and of the Apollo Command and Service Modules; problems included a fault in the electrical power system and a 30 percent decrease in pressure to the service module engine 80 seconds after firing.
AS-203	Saturn 1B	Unmanned	July 5, 1966	Earth orbit	Success - fuel tank behavior test and booster certification - informally proposed later as Apollo 2, this name was never approved.
AS-202	Saturn 1B	Unmanned	August 25, 1966	Suborbital	Success - command module reentry test successful, even though reentry was very uncontrolled. Informally proposed as Apollo 3, this name was never approved.
AS-204 (Apollo 1)	Saturn 1B	Virgil I. "Gus" Grissom, Edward White, Roger B. Chaffee	(Launch cancelled)	Earth orbit	Failure - never launched: command module destroyed and three astronauts killed on 27 January 1967 by fire in the module during a test exercise - Retroactively, the mission's name was officially changed to "Apollo 1" after the fire. Although it was scheduled to be the fourth Apollo mission (and despite the fact that NASA planned to call the mission AS-204), the flight patch worn by the three astronauts, which was approved by NASA in June 1966, already referred to the mission as "Apollo 1"
Apollo 4	Saturn V	Unmanned	November 9, 1967	Earth orbit	Success - first test of new booster and all elements together (except lunar module), successful reentry of command module
Apollo 5	Saturn 1B	Unmanned	January 22, 1968	Earth orbit	Success - first flight of lunar module (LM); multiple space tests of LM, no command or service module flown; no controlled reentry. Used the Saturn 1B originally slated for the cancelled manned AS-204 ("Apollo 1") mission
Apollo 6	Saturn V	Unmanned	April 4, 1968	Earth orbit	Partial success - severe oscillations during orbital insertion, several engines failing during flight, successful reentry of command module (though mission parameters for a 'worst case' reentry scenario could not be achieved)
Apollo 7	Saturn 1B	Walter M. "Wally" Schirra, Donn Eisele, Walter Cunningham	October 11, 1968	Earth orbit	Success - first manned Apollo mission; 11 days in Earth orbit; flight test of CSM (no LM); crew suffered from head colds
Apollo 8	Saturn V	Frank Borman, Jim Lovell, William A. Anders	December 21, 1968	Lunar orbit	Success - first manned lunar flight; CSM only (no LM); first humans to see lunar far side and earthrise with own eyes; problems with sleep deprivation and space sickness; mission profile selected relatively late to beat possible similar Russian attempt
Apollo 9	Saturn V	James McDivitt, David Scott, Russell L. "Rusty" Schweickart	March 3, 1969	Earth orbit	Success - first manned LM flight; 10 days in Earth orbit on engineering shakedowns of CSM and LM; EVA tested lunar portable life support system (PLSS)
Apollo 10	Saturn V	Thomas P. Stafford, John W. Young, Eugene Cernan	May 18, 1969	Lunar orbit	Success - first test of LM in lunar orbit; "dress rehearsal" of first landing; LM entered descent orbit with 8.4 nautical miles (15.6 km) pericynthion
Apollo 11	Saturn V	Neil Armstrong, Michael Collins, Edwin E. "Buzz" Aldrin	July 16, 1969	Lunar landing	Success - first manned landing on the Moon; one EVA in direct vicinity of landing site; navigation errors and computer alarms overcome
Apollo 12	Saturn V	Charles "Pete" Conrad, Richard Gordon, Alan Bean	November 14, 1969	Lunar landing	Success - successful precision landing near Surveyor 3 probe; two EVAs, returned Surveyor parts to earth; first controlled LM ascent stage impact after jettison; first use of deployable S-band antenna; two lightning strikes after liftoff with brief loss of fuel cells and telemetry; lunar TV camera damaged by accidental exposure to sun
Apollo 13	Saturn V	Jim Lovell, Jack Swigert, Fred Haise	April 11, 1970	Lunar landing	Partial Failure - aborted during trans-lunar cruise by SM oxygen tank explosion; used LM as crew "lifeboat" for return trip via lunar farside; early shutdown of inboard S-II engine did not affect mission; first S-IVB lunar impact
Apollo 14	Saturn V	Alan B. Shepard, Stuart Roosa, Edgar Mitchell	January 31, 1971	Lunar landing	Success - landed at Fra Mauro site intended for Apollo 13; mission overcame docking problems, faulty LM abort switch and delayed landing radar acquisition; first color video images from the Moon; first materials science experiments in space; two EVAs
Apollo 15	Saturn V	David Scott, Alfred Worden, James Irwin	July 26, 1971	Lunar landing	Success - first "J series" mission with 3 day lunar stay and extensive geology investigations; first use of lunar rover (17.25 miles (27.76 km) driven); 1 lunar "standup" EVA, 3 lunar surface EVAs plus deep space EVA
Apollo 16	Saturn V	John W. Young, Ken Mattingly, Charles Duke	April 16, 1972	Lunar landing	Success - only landing in lunar highlands; malfunction in a backup CSM yaw gimbal servo loop delayed landing and reduced stay in lunar orbit; no ascent stage deorbit due to malfunction; 3 lunar EVAs plus deep space EVA
Apollo 17	Saturn V	Eugene Cernan, Ronald Evans, Harrison H. "Jack" Schmitt	December 7, 1972	Lunar landing	Success - last Apollo lunar landing; last (to date) human flight beyond low earth orbit; only lunar mission with a scientist (geologist); 3 lunar EVAs plus deep space EVA
Planned Apollo 18, 19, and 20	Saturn V	Missions cancelled	Never launched	Lunar landings	Cancelled - Three more moon landings were planned, but cancelled to cut costs

Samples returned

Main article: Moon rock

Lunar Mission	Sample Returned	Representative Sample
Apollo 11	22 kg
Apollo 12	34 kg
Apollo 14	43 kg
Apollo 15	77 kg	The most famous of the Moon rocks recovered, the Genesis Rock, was discovered and returned from the Apollo 15 mission.
Apollo 16	95 kg	Ferroan Anorthosite moon rock, collected by Apollo 16. The only sources of moon rocks on Earth are those collected from the Apollo program, the former Soviet Union's Luna missions, and lunar meteorites. Future missions manned or unmanned would provide the opportunity to collect more.
Apollo 17	111 kg

The Apollo program returned 381.7 kg (841.5 lb) of rocks and other material from the Moon, much of which is stored at the Lunar Receiving Laboratory in Houston.

The rocks collected from the Moon are extremely old compared to rocks found on Earth, as measured by radiometric dating techniques. They range in age from about 3.2 billion years old for the basaltic samples derived from the lunar mare, to about 4.6 billion years for samples derived from the highlands crust. As such, they represent samples from a very early period in the development of the Solar System that is largely missing from Earth. One important rock found during the Apollo Program was the Genesis Rock, retrieved by astronauts James Irwin and David Scott during the Apollo 15 mission. This rock, called anorthosite, is composed almost exclusively of the calcium-rich feldspar mineral anorthite, and is believed to be representative of the highland crust. A geochemical component called KREEP was discovered that has no known terrestrial counterpart. Together, KREEP and the anorthositic samples have been used to infer that the outer portion of the Moon was once completely molten (see lunar magma ocean).

Almost all the rocks show evidence for having been affected by impact processes. For instance, many samples appear to be pitted with micrometeoroid impact craters, something which is never seen on earth due to its thick atmosphere. Additionally, many show signs of being subjected to high pressure shock waves that are generated during impact events. Some of the returned samples are of impact melt, referring to materials that are melted near an impact crater. Finally, all samples returned from the Moon are highly brecciated as a result of being subjected to multiple impact events.

Analysis of composition of the lunar samples support the giant impact hypothesis, that the Moon was created through a "giant impact" of a large astronomical body with the Earth.

Program costs and cancellation

When President Kennedy first chartered the moon landing program, a preliminary cost estimate of $7 billion dollars was generated, but this proved an extremely unrealistic guess of what could not possibly be determined precisely, and James Webb used his administrator's judgement to change the estimate to $20 billion before giving it to Vice President Johnson. Webb's estimate shocked everyone at the time, but ultimately proved to be reasonably accurate. The final cost of project Apollo was reported to Congress as $25.4 billion in 1973.

In 2009, NASA held a symposium on project costs which presented an estimate of the Apollo program costs in 2005 dollars as roughly $170 billion. This included all Research and development (R&D) costs; the procurment 15 Saturn V rockets, 16 Command/Service Modules, 12 Lunar Modules, plus program support and management costs; construction expenses for facilities and their upgrading, and costs for flight operations. This was based on a Congressional Budget Office report, A Budgetary Analysis of NASA’s New Vision for Space, dated Sept 2004.

Canceled missions

Main article: Canceled Apollo missions

Originally three additional lunar landing missions had been planned, as Apollo 18 through Apollo 20. In light of the drastically shrinking NASA budget and the decision not to produce a second batch of Saturn Vs, these missions were canceled to make funds available for the development of the Space Shuttle, and to make their Apollo spacecraft and Saturn V launch vehicles available to the Skylab program. Only one of the remaining Saturn Vs was actually used to launch the Skylab orbital laboratory in 1973; the others became museum exhibits at the John F. Kennedy Space Center on Merritt Island, Florida, George C. Marshall Space Center in Huntsville, Alabama, Michoud Assembly Facility in New Orleans, Louisiana, and Lyndon B. Johnson Space Center in Houston, Texas.

Scientific and engineering legacy

Unflown command module CM-007 at the Museum of Flight in Seattle

The Apollo program, specifically the lunar landings, has been called the greatest technological achievement in human history. The program stimulated many areas of technology. The flight computer design used in both the lunar and command modules was, along with the Minuteman Missile System, the driving force behind early research into integrated circuits. The fuel cell developed for this program was the first practical fuel cell. Computer-controlled machining (CNC) was pioneered in fabricating Apollo structural components.

Further information: [[:NASA Spinoff Technologies]]

Influence on future human space exploration

Further information: [[:List of current and future lunar missions]]

Several nations have planned future human lunar missions, and several space agencies also intend to build lunar bases.

Neil Armstrong, the commander of the first successful landing Apollo 11, is often asked by the press for his views on the future of spaceflight. In 2005, he said that a human voyage to Mars will be easier than the lunar challenge of the 1960s: "I suspect that even though the various questions are difficult and many, they are not as difficult and many as those we faced when we started the Apollo (space program) in 1961."

Constellation program

In a speech on January 14, 2004, President George W. Bush announced a new Vision for Space Exploration, which included plans for the United States to return astronauts to the Moon no later than 2020 (with the first human landing currently targeted for 2019). This mission would be a part of the Constellation program, a proposal to create a new generation of manned spacecraft. This would include the Orion spacecraft, similar to Apollo's CSM but holding a larger crew, which would also replace the Space Shuttle as an earth orbit crew vehicle.

NASA proceeded with plans to start developing the Orion spacecraft and its Ares I low Earth orbit launch vehicle (analagous to the Saturn IB). The Ares I development philosophy returned to that of the original Saturn I, test-launching one stage at a time, which George Mueller abandoned in favor of "all-up" testing for the Saturn V. The program has gotten as far as launching the first Ares I-X first-stage flight on October 28, 2009.

However, the Obama administration decided to exclude Constellation from the 2011 United States federal budget. On February 1, 2010, the President's proposed budget was released, which included no funding for the project.

Cultural legacy

A world wide audience

"Everything that I ever knew - my life, my loved ones, the Navy - everything, the whole world was behind my thumb." –James Lovell

The Apollo 8 crew's 1968 Christmas Eve broadcast was the most widely watched television broadcast up until that time. The broadcast's historic significance and worldwide impact is discussed here.

Approximately one fifth of the population of the world watched the live transmission of the first Apollo moonwalk.

Apollo 11 broadcast data restoration project

As part of its 40th anniversary celebrating the Apollo program, NASA has promoted the restoration of data recorded during the televised Apollo 11 moon landing. After a 3 year exhaustive search for missing tapes that contained the original footage of the Apollo 11 moonwalk, NASA concluded the missing data tapes were more than likely destroyed during a period when they were erasing old magnetic tapes and reusing them to record satellite data.

We're all saddened that they're not there. We all wish we had 20-20 hindsight. I don't think anyone in the NASA organization did anything wrong, I think it slipped through the cracks, and nobody's happy about it.

— Dick Nafzger, TV Specialist, NASA Goddard Space Flight Center

The moon landing data was recorded by a special lunar camera which recorded in a format that wasn't compatible with the format used for broadcast TV. This resulted in lunar footage that had to be converted for the live television broadcast and stored on magnetic telemetry tapes. During the years that followed the Apollo program, a magnetic tape shortage prompted NASA to remove massive numbers of magnetic tapes from the National Archives and Records Administration to be recorded over with newer satellite data. Stan Lebar, who designed and built the lunar camera at Westinghouse Electric Corporation, also worked with Nafzger to locate the missing tapes. The search concluded that the missing original data lunar tapes were lost.

So I don't believe that the tapes exist today at all. It was a hard thing to accept. But there was just an overwhelming amount of evidence that led us to believe that they just don't exist anymore. And you have to accept reality.

— Stan Lebar, Lunar Camera Designer, Westinghouse Electric Corporation

With a budget of $230,000, the surviving original lunar broadcast data from Apollo 11 was compiled by Nafzger and assigned to Lowry Digital for restoration. Due to be complete in September 2009, the video will be processed to remove random noise and camera shake without destroying historical legitimacy.

We've got to be very, very mindful of history. If you want to go to the extreme, you could take these images and completely re-create them. You could create a three-dimensional model of the lunar lander, and you could make it look beautiful. But I don't think that's the point. I think the point is that Apollo 11 was a very, very special historical event.

— John Lowry, Founder, Lowry Digital

The images that Lowry Digital is working with have been taken from tapes in Australia, the CBS News archive, and kinescope recordings made at Johnson Space Center. The restored Apollo landing video will remain in black and white, contain conservative digital enhancements and will not include sound quality improvements.

Psychological impact on the astronauts

"We went to explore the Moon, and in fact discovered the Earth." –Eugene Cernan

Many astronauts and cosmonauts have commented on the profound effects that seeing Earth from space has had on them; the twenty-four astronauts who traveled to the Moon are the only humans to have observed Earth from beyond low Earth orbit, and have traveled further from Earth than anyone else to date.

One of the most important legacies of the Apollo program is the now-common view of Earth as a fragile, small planet, captured in the photographs taken by the astronauts during the lunar missions. The most famous of these photographs, taken by the Apollo 17 astronauts, is "The Blue Marble" (see image at right). These photographs have also motivated many people toward environmentalism.

Historical observation

"There the lunar module sits, parked just where it landed 40 years ago, as if it still really were 40 years ago and all the time since merely imaginary." –The New York Times

In 2008, JAXA's SELENE probe observed evidence of the halo surrounding the Apollo 15 lunar module blast crater while orbiting above the lunar surface.

In 2009, NASA's robotic Lunar Reconnaissance Orbiter, while orbiting 50 kilometres (31 mi) above the Moon, photographed the remnants of the Apollo program left on the lunar surface, and photographed each site where manned Apollo flights landed.

In a November 16, 2009 editorial, The New York Times opined that:

[T]here’s something terribly wistful about these photographs of the Apollo landing sites. The detail is such that if Neil Armstrong were walking there now, we could make him out, make out his footsteps even, like the astronaut footpath clearly visible in the photos of the Apollo 14 site.

Perhaps the wistfulness is caused by the sense of simple grandeur in those Apollo missions. Perhaps, too, it’s a reminder of the risk we all felt after the Eagle had landed — the possibility that it might be unable to lift off again and the astronauts would be stranded on the Moon. But it may also be that a photograph like this one is as close as we’re able to come to looking directly back into the human past.

— New York Times

Proposed future lunar missions, such as the Google Lunar X Prize, intend to land robotic spacecraft on the lunar surface and record close-up videos and photographs of the Apollo Lunar Modules and other artificial objects on the surface.

Documentaries

Numerous documentary films cover the Apollo project and the space race, including:

• Moonwalk One (1970)
• For All Mankind (1989)
• Moon Shot (documentary commemorating 25 years since the landings) (1994)
• From the Earth to the Moon (TV miniseries) (1998)
• "Moon" from the BBC miniseries The Planets (1999)
• Magnificent Desolation: Walking on the Moon 3D (2005)
• In the Shadow of the Moon (2007)
• When We Left Earth: The NASA Missions (miniseries) (2008)
• James May on the Moon (documentary commemorating 40 years since the landings) (2009)
• NASA's Story

Robbins Medallion flown on Apollo 14

See also

• Apollo 1 - unflown mission
• Apollo 2, Apollo 3, Apollo 4, Apollo 5, Apollo 6 - unmanned missions
• Apollo 18, Apollo 19, Apollo 20 - canceled missions
• Project Mercury
• Project Gemini
• Apollo Moon Landing hoax conspiracy theories
• Apollo TV camera
• List of artificial objects on the Moon
• Pad Abort Tests
• Soviet Moonshot

References

• "Discussion of Soviet Man-in-Space Shot," Hearing before the Committee on Science and Astronautics, U.S. House of Representatives, 87th Congress, First Session, April 13, 1961.
• Hansen, James R. (1995). Enchanted Rendezvous: John C. Houbolt and the Genesis of the Lunar-Orbit Rendezvous Concept (PDF). NASA. Retrieved 2008-12-28.
• Launius, Roger (1997). Spaceflight and the Myth of Presidential Leadership. Urbana: University of Illinois Press. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Murray, Charles (1989). Apollo: The Race to the Moon. New York: Simon and Schuster. ISBN 0-671-61101-1. OCLC 19589707. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Papike, James (1998). "Lunar Samples". Reviews in Mineralogy and Geochemistry. 36: 5.1–5.234. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Sidey, Hugh (1963). John F. Kennedy, President. New York: Atheneum.
• Swenson, Jr., Loyd S. (1979). Chariots for Apollo: A History of Manned Lunar Spacecraft. NASA. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

Further reading

• Chaikin, Andrew. A Man on the Moon. ISBN 0-14-027201-1. Chaikin has interviewed all the surviving astronauts, plus many others who worked with the program.
• Collins, Michael. Carrying the Fire; an Astronaut's journeys. Astronaut Mike Collins autobiography of his experiences as an astronaut, including his flight aboard Apollo 11, the first landing on the Moon
• Cooper, Henry S. F. Jr. Thirteen: The Flight That Failed. ISBN 0-8018-5097-5. Although this book focuses on Apollo 13, it is extremely well-researched and provides a wealth of background information on Apollo technology and procedures.
• French, Francis and Burgess, Colin, In the Shadow of the Moon: A Challenging Journey to Tranquility, 1965-1969. ISBN 978-0-8032-1128-5. History of the Apollo program from Apollo 1-11, including many interviews with the Apollo astronauts.
• Kranz, Gene, Failure is Not an Option. Factual, from the standpoint of a chief flight controller during the Mercury, Gemini, and Apollo space programs. ISBN 0-7432-0079-9.
• Lovell, Jim; Kluger, Jeffrey. Lost Moon: The perilous voyage of Apollo 13 aka Apollo 13: Lost Moon. ISBN 0-618-05665-3. Details the flight of Apollo 13.
• Orloff, Richard W. SP-4029 Apollo by the Numbers: A Statistical Reference
• Pellegrino, Charles R.; Stoff, Joshua. Chariots for Apollo: The Untold Story Behind the Race to the Moon. ISBN 0-380-80261-9. Tells Grumman's story of building the Lunar Modules.
• Robert C. Seamans, Jr. Project Apollo: The Tough Decisions. ISBN 0-1607-4954-9. Presents the history of the manned space program from September 1, 1960 to January 5, 1968.
• Slayton, Donald K.; Cassutt, Michael. Deke! An Autobiography. ISBN 0-312-85918-X. This is an excellent account of Deke Slayton's life as an astronaut and of his work as chief of the astronaut office, including selection of the crews which flew Apollo to the Moon.
• Template:PDFlink From origin to November 7, 1962
• Template:PDFlink November 8, 1962 - September 30, 1964
• Template:PDFlink October 1, 1964 - January 20, 1966
• Template:PDFlink January 21, 1966 - July 13, 1974
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• Wilhelms, Don E. To a Rocky Moon. ISBN 0-8165-1065-2. Tells the history of Lunar exploration from a geologist's point of view.
• The long Way to the Moon - and back, 2009, AtheneMedia Publishing ISBN 978-3-86992-012-2,

External links

• Official Apollo program website
• Apollo photo gallery at NASA Human Spaceflight website (includes videos/animations)
• Audio recording and transcript of President John F. Kennedy, NASA administrator James Webb et al. discussing the Apollo agenda (White House Cabinet Room, November 21, 1962)
• U.S. Spaceflight History- Apollo Program
• Apollo Image Atlas almost 25,000 lunar images, Lunar and Planetary Institute
• Project Apollo at NASA History Division
• The Apollo Lunar Surface Journal
• How Apollo Has Influenced Society
• The Apollo Flight Journal
• Project Apollo Drawings and Technical Diagrams
• Apollo Program Summary Report (Technical)
• The Apollo Program (National Air and Space Museum)
• Apollo 35th Anniversary Interactive Feature (in Flash)
• Exploring the Moon: Apollo Missions
• Apollo Archive - large repository of information about the Apollo program.
• Apollo Flight Film Archive - repository of scanned Apollo flight film (in high resolution).
• NASA History Series Publications (many of which are on-line)
• Apollo's Contributions to Society
• Was The Apollo Program a Prudent Investment Worth Retrying?