Apollo program
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Reverted edits by [[Special:Contributions/Reconfirmer|Reconfirmer]] to last version by Pfainuk (using [[WP:HG|Huggle]])
[[Image:Apollo program insignia.png|200px|right|Apollo program insignia]]
The '''Apollo program''' was a [[human spaceflight]] program undertaken by [[NASA]] during the years 1961 – 1975 with the goal of conducting manned [[moon landing]] missions. President [[John F. Kennedy]] announced this goal in 1961, and it was accomplished on [[July 20]] [[1969]] by [[Neil Armstrong]] and [[Buzz Aldrin]] during the ''[[Apollo 11]]'' mission. Five other Apollo missions also landed [[astronaut]]s on the [[Moon]], the last one in 1972. These six Apollo spaceflights are the only times humans have landed on another [[celestial body]]. The Apollo program, specifically the [[lunar landing]]s, is often cited as the greatest achievement in human history.<ref>[http://history.nasa.gov/ap11ann/introduction.htm NASA: 30th Anniversary of Apollo 11]</ref><ref>[http://news.bbc.co.uk/1/hi/special_report/1999/07/99/the_moon_landing/396037.stm BBC: 30th Anniversary of Apollo 11]</ref>
Apollo was the third human spaceflight program undertaken by NASA, the [[space agency]] of the [[United States]]. It used [[Apollo spacecraft]] and [[Saturn (rocket family)|Saturn]] launch vehicles, which were later used for the [[Skylab|Skylab program]] and the joint American-Soviet [[Apollo-Soyuz Test Project]]. These later programs are thus often considered to be part of the overall Apollo program.
The goal of the program, as articulated by [[President of the United States|President]] Kennedy, was accomplished with only two major failures. The first failure resulted in the deaths of three astronauts, [[Gus Grissom]], [[Edward Higgins White|Ed White]] and [[Roger Chaffee]], in the [[Apollo 1]] launchpad fire. The second was an in-space explosion on [[Apollo 13]], which badly damaged the spacecraft on the moonward leg of its journey. 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 themselves.
The program set major milestones in the history of human spaceflight. This program remains alone in sending manned missions beyond [[low Earth orbit]]. [[Apollo 8]] was the first manned spacecraft to orbit another celestial body, while [[Apollo 17]] marks the time of the last moonwalk and also the last manned mission beyond [[low Earth orbit]].
The program spurred advances in many areas of technology peripheral to rocketry and manned spaceflight. These include major contributions in the fields of [[avionics]], [[telecommunications]], and [[computers]]. The program sparked interest in many fields of [[engineering]], including pioneering work using [[statistical]] methods to study the [[MTBF|reliability]] of complex systems made from component parts. The physical facilities and machines which were necessary components of the manned spaceflight program remain as landmarks of [[civil engineering|civil]], [[mechanical engineering|mechanical]], and [[electrical engineering]].
Many objects and artifacts from the program are on display at various locations throughout the world, notably at the [[National Air and Space Museum|Smithsonian's Air and Space Museums]].
==Background==
{{main|Space race}}
The Apollo program was originally conceived early in 1960, during the [[Dwight D. Eisenhower|Eisenhower]] administration, as a follow-up to America's [[Project Mercury|Mercury program]]. While the Mercury capsule could only support one astronaut on a limited earth orbital mission, the Apollo spacecraft was intended to be able to carry three astronauts on a circumlunar flight and perhaps even on a lunar landing. The program was named after the [[Apollo|Greek god of light and archery]] by NASA manager [[Abe Silverstein]], who later said that "I was naming the spacecraft like I'd name my baby."<ref>Murray and Cox, ''Apollo'', p. 55.</ref> While NASA went ahead with planning for Apollo, funding for the program was far from certain, particularly given Eisenhower's equivocal attitude to manned spaceflight.<ref>Murray and Cox, ''Apollo'', p. 60.</ref>
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."<ref>Beschloss, 'Kennedy and the Decision to Go to the Moon,' in Launius and McCurdy, eds., ''Spaceflight and the Myth of Presidential Leadership''.</ref> 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.<ref>Sidey, ''John F. Kennedy'', pp. 117-118.</ref> When NASA Administrator [[James Edwin Webb|James Webb]] requested a thirty percent budget increase for his agency, Kennedy supported an acceleration of NASA's large booster program but deferred a decision on the broader issue.<ref>Beschloss, 'Kennedy and the Decision to Go to the Moon,' p. 55.</ref>
On [[April 12]], [[1961]], Soviet cosmonaut [[Yuri Gagarin]] became the first man 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.<ref>"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]].</ref> Kennedy, however, was circumspect in his response to the news, refusing to make a commitment on America's response to the Soviets.<ref>Sidey, ''John F. Kennedy'', p. 114</ref> 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.<ref>Kennedy to Johnson, [http://www.hq.nasa.gov/office/pao/History/Apollomon/apollo1.pdf| "Memorandum for Vice President,"] [[April 20]], [[1961]].</ref> Johnson responded on the following day, concluding that "we are neither making maximum effort nor achieving results necessary if this country is to reach a position of leadership."<ref name="lbjmemo">Johnson to Kennedy, [http://www.hq.nasa.gov/office/pao/History/Apollomon/apollo2.pdf| "Evaluation of Space Program,"] [[April 21]], [[1961]].</ref> His memo concluded that a manned moon landing was far enough in the future to make it possible that the United States could achieve it first.<ref name="lbjmemo"/>
[[Image:Kennedy Moon speech 25 May 1961.jpg|thumb|left|The Decision to Go to the Moon: President John F. Kennedy's May 25, 1961 speech before a Joint Session of Congress]]
On [[May 25]], [[1961]], Kennedy announced his support for the Apollo program as part of a special address to a joint session of Congress:
{{cquote|First, 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]]<ref name="Special Message">[[John F. Kennedy]], [http://www.jfklibrary.org/Historical+Resources/Archives/Reference+Desk/Speeches/JFK/Urgent+National+Needs+Page+4.htm "Special Message to the Congress on Urgent National Needs"], [[May 25]] [[1961]]</ref>
}}
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. Some NASA employees doubted whether Kennedy's ambitious goal could be met.<ref>Murray and Cox, ''Apollo'', pp. 16-17.</ref>
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 ($25 billion), ever made by any nation in peacetime. At its peak, the Apollo program employed 400,000 Americans and required the support of over 20,000 industrial firms and universities.<ref>[http://www.nasa.gov/centers/langley/news/factsheets/Apollo.html|NASA Langley Research Center's Contributions to the Apollo Program]</ref>
[[Image:John F. Kennedy speaks at Rice University.jpg|thumbnail|right|President [[John F. Kennedy]] delivers a speech at [[Rice University]] on the subject of the American space program, [[September 12]], [[1962]].]]
{{Cquote|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.
[[John F. Kennedy]]<ref name="Rice Speech">[[John F. Kennedy]],[http://www.jfklibrary.org/Historical+Resources/Archives/Reference+Desk/Speeches/JFK/003POF03SpaceEffort09121962.htm "Address at Rice University on the Nation's Space Effort"]</ref>}}
==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:
[[Image:Apollo Direct Ascent.png|thumb|left|Early Apollo configuration for <br />Direct Ascent and<br /> 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 very powerful booster, the planned [[Nova rocket]].
* '''[[Earth Orbit Rendezvous]] (EOR):''' Two [[Saturn V]] rockets would be launched, one carrying the spacecraft and one carrying a propulsion unit 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 module would remain in orbit around the moon, while a [[lunar module]] would descend to the moon and then return to dock with the command module 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, which had never been attempted in space, would be impossible 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 valid 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.<ref>Brooks, Grimwood and Swenson, ''Chariots for Apollo'', p. 71.</ref>
Seamans' establishment of the Golovin committee in July 1961 represented a turning point in NASA's mission mode decision.<ref name="hansen21"> Hansen, ''Enchanted Rendezvous'', p 21</ref> 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.<ref name="hansen21"/> 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:
{{Cquote|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.<ref>Hansen, ''Enchanted Rendezvous'', p. 27.</ref>}}
==Spacecraft==
{{main|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 [[Apollo Command/Service Module|Command/Service Module]] (CSM), in which the crew would spend most of the mission, and the [[Apollo Lunar Module|Lunar Module]] (LM), which would descend to and return from the lunar surface.
===Command/service module===
[[Image:Apollo CSM lunar orbit.jpg|thumb|right|Apollo CSM in lunar orbit.]]
The [[Apollo Command/Service Module#Command Module (CM)|command module]] (CM) was conical in shape, and was designed to carry three astronauts from launch into lunar orbit and back from the moon to splashdown. Equipment carried by the command module included [[Thruster|reaction control engines]], a docking tunnel, guidance and navigation systems and the [[Apollo Guidance Computer]]. Attached to the command module was the [[Apollo Command/Service Module#Service Module (SM)|service module]] (SM), which housed the service propulsion system and its propellants, the fuel cell power system, four maneuvering thruster quads, the S-band antenna for communication with Mission Control, and storage tanks for water and air. On Apollo 15, 16 and 17 it also carried a scientific instrument package. The two sections of the spacecraft would remain attached until just prior to re-entry, at which point the service module would be discarded. Only the command module was provided with a heat shield that would allow it and its passengers to survive the intense heat of re-entry. After re-entry it would deploy parachutes that would slow its descent through the atmosphere, allowing a smooth splashdown in the ocean.
Under the leadership of [[Harrison Storms]], [[North American Aviation]] won the contract to build the CSM for NASA. Relations between North American and NASA were strained during the Apollo program, particularly after the [[Apollo 1]] fire during which three astronauts died. The cause of the accident was determined to be an electrical short in the wiring of the command module; while determination of responsibility for the accident was complex, the review board concluded that "deficiencies existed in Command Module design, workmanship and quality control."<ref>[http://www.hq.nasa.gov/office/pao/History/Apollo204/find.html| Report of the Apollo 204 Review Board, Findings and Recommendations]</ref>
===Lunar module===
[[Image:Apollo 16 LM.jpg|thumb|left|Apollo LM on lunar surface.]]
The [[Apollo Lunar Module|Lunar Module (LM)]] (also known as Lunar Excursion Module, or LEM), was designed solely in order to [[landing|land]] on the moon, and to ascend from the lunar surface to the command module. It had a limited heat shield and was of a construction so lightweight that it would not have been able to fly in Earth gravity. It carried two crewmembers and 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]], and the project was overseen by [[Tom Kelly (engineer)|Tom Kelly]]. There were also problems with the lunar module; due to delays in the test program, the LM became what was known as a "pacing item," meaning that it was in danger of delaying the schedule of the whole Apollo program.<ref>[http://www.hq.nasa.gov/office/pao/History/SP-4205/ch7-4.html| Chariots for Apollo, Ch 7-4]</ref> Due to 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.
<br clear=all/>
==Boosters==
When the team of engineers led by [[Wernher von Braun]] began planning for the Apollo program, it was not yet clear what sort of mission their rocket boosters would have to support. Direct ascent would require a booster, the planned [[Nova rocket]], which could lift a very large payload. NASA's decision in favor of lunar orbit rendezvous re-oriented the work of [[Marshall Spaceflight Center]] towards the development of the [[Saturn 1B]] and [[Saturn V]]. While these were less powerful than the Nova would have been, the Saturn V was still much more powerful than any booster developed before—or since.
===Saturn V===
{{main|Saturn V}}
[[Image:Ksc-69pc-442.jpg|thumb|right|The [[Saturn V]] [[Saturn (rocket family)|rocket]] launched ''[[Apollo 11]]'' and her crew on its journey to the [[Moon]], [[16 July]] [[1969]].]][[Image:Saturn V diagram from Apollo 6 Press Kit.jpg|thumb|left|Saturn V diagram from the Apollo 6 press kit]]The Saturn V consisted of three stages and an [[Saturn V Instrument Unit|Instrument Unit]] which contained the booster's guidance system. The first stage, the [[S-IC]], consisted of five F-1 engines arranged in a cross pattern, which produced a total of 7.5 million pounds of thrust. They burned for only 2.5 minutes, accelerating the spacecraft to a speed of approximately 6000 miles per hour (2.68 km/sec).<ref> Saturn V News Reference: First Stage Fact Sheet</ref> During development, the F-1 engines were plagued by combustion instability—if the combustion of propellants was not uniform across the flame front of an engine, pressure waves could build which would cause the engine to destroy itself. The problem was solved in the end through trial and error, fine-tuning the engines through numerous tests so that even small charges set off inside the engine would not induce instability.<ref>Murray and Cox, ''Apollo'', pp. 145-51, 179-81.</ref>
The second stage, the [[S-II]], used five [[J-2 (rocket engine)|J-2]] engines. They burned for approximately six minutes, taking the spacecraft to a speed of 15,300 miles per hour (6.84 km/sec) and an altitude of about <span style="white-space:nowrap">115 miles (185 km)</span>.<ref> Saturn V News Reference: Second Stage Fact Sheet</ref> At this point the [[S-IVB]] third stage took over, putting the spacecraft into orbit. Its one J-2 engine was designed to be restarted in order to make the [[Trans lunar injection|translunar injection]] burn.<ref>Saturn V News Reference: Third Stage Fact Sheet</ref>
===Saturn IB===
{{main|Saturn IB}}
The [[Saturn IB]] was an upgraded version of the earlier [[Saturn I]]. It consisted of a first stage made up of eight [[H-1 (rocket engine)|H-1]] engines and a second S-IVB stage which was identical to the Saturn V's third stage. The Saturn IB had only 1.6 million pounds of thrust in its first stage—compared to 7.5 million pounds for the Saturn V—but was capable of putting a command and lunar module into earth orbit.<ref> Saturn IB News Reference: Saturn IB Design Features</ref> It was used in Apollo test missions and in both the Skylab program and the Apollo-Soyuz Test Program. In 1973 a refitted S-IVB stage, launched by a Saturn V, became the [[Skylab]] space station.
==Missions==
{{seealso|List of Apollo missions}}
===Mission types===
In September 1967, the [[Lyndon B. Johnson Space Center|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 specific 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 [[Apollo Command/Service Module|Command/Service Module]] (CSM) test
* '''B''' - Unmanned [[Apollo Lunar Module|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 [[ellipse|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 [[Extra-vehicular activity|LEVAs]] ("moonwalks"). These were followed by the J missions, which were longer three day stays, with three LEVAs and the use of the [[lunar rover]]. ''Apollo 18'' to ''20'' would have been J missions. In addition, a further group of flights — the I missions — were planned, which would have been long duration orbital missions using a Service Module bay loaded with scientific equipment. When it became obvious that later flights were being cancelled, such mission plans were brought into the J missions that were actually flown.
===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 (rocketry)|boilerplate]] models of the Apollo command/service module. Two [[pad abort test]]s of the [[launch escape system]] took place in 1963 and 1965 at the [[White Sands Missile Range]].
The only unmanned missions to officially include Apollo as part of their name rather than serial number were [[Apollo 4]], [[Apollo 5]] and [[Apollo 6]].<ref>Murray and Cox, ''Apollo'', p. 238.</ref> 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 vibrations in the booth's plate glass window to prevent it from shattering.<ref>Murray and Cox, ''Apollo'', p. 248.</ref> This launch showed that additional protective measures against the [[shock wave]] were necessary to protect structures in the immediate vicinity. Future launches used a damping mechanism directly at the launchpad which proved effective in confining the main effects of the shock wave to the blast area.<ref>[[Apollo_4#Flight]]</ref>.
Apollo 6 was the last in the series of unmanned Apollo missions. It launched on [[April 4]], [[1968]], and landed back on Earth almost ten hours later at 21:57:21 [[Coordinated Universal Time|UTC]].
===Manned missions===
<!-- Deleted image removed: [[Image:Hurriyet21July1969.jpg|thumb|A Turkish newspaper [[Hürriyet]], [[July 21]] [[1969]]]] -->
[[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.
By the summer of 1968 it became clear to program managers that a fully functional [[Apollo Lunar Module|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 program|Zond]] spacecraft around the moon, there is no evidence that this was actually 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. It is relatively certain that the Apollo 8 decision was primarily based upon the LM schedule, rather than 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.
[[Image:Apollo 11 first step.jpg|thumb|left|A [[Apollo TV camera|mounted camera]] captures [[Neil Armstrong]] as he becomes the first human to step on the moon.]][[Image:Buzz salutes the U.S. Flag.jpg|thumb|right|This image shows Apollo 11 astronaut Buzz Aldrin with the [[Flag of the United States|U.S. flag]]. The illusion of a breeze was caused by the horizontal rod intended to hold the flag flat failing to telescope out completely, thus leaving ripples in the fabric like those seen in a flag in the wind.]]
{{Cquote|That's one small step for [a] man, one giant leap for mankind.
[[Neil Armstrong]]<ref>[[Neil Armstrong#First_Moon_walk]]</ref>}}
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. It appears that much of the original film and telemetry data for the [[Apollo 11]] mission is missing. For more information see [[Apollo program missing tapes]].
[[Image:Apollo17 plaque.jpg|thumb|left|On the last of the [[List of Apollo missions|Apollo missions]], the crew of [[Apollo 17]] left this plaque as was done on all the previous landings.]] [[Apollo 17]] launched [[December 7]], [[1972]] and 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|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 IB]]s, 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]], whilst 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]].
==Samples returned==
{{main|Moon rock}}
{| border="1" cellspacing="0" cellpadding="4" align="right" class="wikitable"
!Lunar<br />Mission
!Sample<br />Returned
!Representative<br />Sample
|-
|[[Apollo 11]]
|align="right"|22 kg
|-
|[[Apollo 12]]
|align="right"|34 kg
|-
|[[Apollo 14]]
|align="right"|43 kg
|-
|[[Apollo 15]]
|align="right"|77 kg
|[[Image:Apollo 15 Genesis Rock.jpg|thumb|center|The most famous of the Moon rocks recovered, the ''[[Genesis Rock]]'', was discovered and returned from the ''[[Apollo 15]]'' mission.]]
|-
|[[Apollo 16]]
|align="right"|95 kg
|[[Image:Lunar Ferroan Anorthosite 60025.jpg|thumb|150px|center|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 programme|Luna missions]], and lunar meteorites. Future missions manned or unmanned would provide the opportunity to collect more.]]
|-
|[[Apollo 17]]
|align="right"|111 kg
|-
|}
The Apollo program returned 381.7 kg (841.5 lb) of [[Moon rocks|rocks and other material from the Moon]], much of which is stored at the [[Lunar Receiving Laboratory]] in Houston.
In general 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 [[basalt]]ic samples derived from the [[lunar mare]], to about 4.6 billion years for samples derived from the [[Lunar highlands|highlands]] crust.<ref>{{cite journal | last = James Papike, Grahm Ryder, and Charles Shearer | title = Lunar Samples | journal = Reviews in Mineralogy and Geochemistry | volume = 36 | pages = 5.1–5.234 | date = 1998 }}</ref> 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 of 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 in the vicinity of an impact crater. Finally, all samples returned from the Moon are highly [[breccia]]ted as a result of being subjected to multiple impact events.
Analysis of composition of the lunar samples led to the conclusion, reached in 1984, that the Moon was created through a "giant impact" of a large astronomical body with the Earth.<ref>
{{cite book |last=Burrows |first=William E. |title=This New Ocean: The Story of the First Space Age |year=1999 |publisher=Modern Library | pages=p. 431 |isbn=0375754857}}</ref>
==Program costs and cancellation==
In March 1966, NASA told Congress the "run-out cost" of the Apollo program to put men on the moon would be an estimated $22.718 Billion for the 13-year program which eventually accomplished six successful missions between July 1969 and December 1972.
According to Steve Garber, the NASA History website curator, the final cost of project Apollo was between $20 and $25.4 Billion in 1969 Dollars (or approximately $135 Billion in 2005 Dollars).
The costs associated with the [[Apollo spacecraft]] and Saturn rockets amounted to about $83 Billion [Apollo spacecraft: $28 Billion ([[Command/Service Module]]: $17 Billion; [[Lunar Module]]: $11-billion), [[Saturn I]], [[Saturn IB]], [[Saturn V]] launch vehicles: about $46 Billion] in 2005 dollars.
===Canceled missions===
{{main|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]] in [[Cape Canaveral]], [[Florida]], [[Marshall Space Flight Center|George C. Marshall Space Center]] in [[Huntsville]], [[Alabama]] and [[Lyndon B. Johnson Space Center]] in [[Houston]], [[Texas]].
==Scientific and engineering legacy==
[[Image:ApolloCmd.JPG|thumbnail|left|Unflown command module CM-007 at the [[Museum of Flight]] in [[Seattle]]]]
The Apollo program stimulated many areas of technology. The [[Apollo Guidance Computer|flight computer]] design used in both the lunar and command modules was, along with the [[LGM-30 Minuteman|Minuteman Missile System]], the driving force behind early research into [[integrated circuit]]s. 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|[[NASA Spinoff|NASA Spinoff Technologies]]}} and [http://www.sti.nasa.gov/tto/apollo.htm How Apollo Has Influenced Society]
===Influence on future human space exploration===
{{further|[[List of future lunar missions]]}}
Several nations have planned [[List of future lunar missions#Human|future human lunar missions]], and several space agencies also intend to build [[Lunar outpost|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 spaceflight|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."
<br clear=all/>
====Constellation program====
{{main|Project Constellation}}
In a speech on [[January 14]], [[2004]], [[President of the United States|President]] [[George W. Bush|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 -- [[Orion 17]] -- currently planned for 2019). This mission would be a part of [[Project Constellation]], NASA's program to create a new generation of [[spacecraft]] for [[human spaceflight]].
Replacing the [[Space Shuttle]] following its retirement in 2010 will be the [[Orion (spacecraft)|Orion]] crew capsule, which closely resembles the Apollo command module in its aerodynamic shape. NASA administrator [[Michael Griffin]] has described the capsule as "Apollo on steroids," and the ''New Scientist'' magazine reports that "some critics... say the whole Orion program is little more than a throwback to Apollo-era technology."<ref>[http://space.newscientist.com/article/dn9895-nasa-to-boldly-go-with-lockheed-martin.html NASA to boldly go... with Lockheed Martin - space - 01 September 2006 - New Scientist Space<!-- Bot generated title -->]</ref> In other respects, however—including its cockpit displays and its heatshield—Orion will be employing new technology.<ref>[http://www.technologyreview.com/printer_friendly_article.aspx?id=17482 Technology Review: Part Apollo, Part Boeing 787<!-- Bot generated title -->]</ref> More closely based on Apollo designs is the upper stage of the [[Ares I]], the launch vehicle designed to take Orion into orbit. It will be based on a [[J-2 (rocket engine)#J-2X|J-2X]] engine, a redesigned version of the J-2 engine used in the Saturn family of boosters. In working on the J-2X, NASA engineers have visited museums, searched for Apollo-era documentation and consulted with engineers who worked on the Apollo program. "The mechanics of landing on the moon and getting off the moon to a large extent have been solved," said Constellation program manager Jeff Hanley. "That is the legacy that Apollo gave us."<ref>[http://www.usatoday.com/tech/science/space/2006-08-14-nasa-apollo_x.htm?csp=34 NASA is borrowing ideas from the Apollo - USATODAY.com<!-- Bot generated title -->]</ref>
Like Apollo, Orion will fly a [[lunar orbit rendezvous]] mission profile, but unlike Apollo, the lander, known as [[Altair (spacecraft)|Altair]], will be launched separately on the [[Ares V]] rocket, a rocket based on both Space Shuttle and Apollo technologies. Orion will be launched separately and will link up with Altair in low earth orbit like that of the Skylab program. Also, Orion, unlike Apollo, will remain unmanned in lunar orbit while the entire crew lands on the lunar surface, with the lunar polar regions in mind instead of the equatorial regions explored by Apollo.
==Cultural legacy==
===A world wide audience===
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 [[Apollo_8#Historical_importance|here]].
Approximately one fifth of the population of the world watched the live transmission of the first [[Apollo 11|Apollo]] moonwalk.<ref>
{{cite book |last=Burrows |first=William E. |title=This New Ocean: The Story of the First Space Age |year=1999 |publisher=Modern Library | pages=p. 429 |isbn=0375754857}}</ref>
===Psychological impact on the astronauts===
[[Image:The Earth seen from Apollo 17.jpg|thumb|"We went to explore the Moon, and in fact discovered the Earth." -[[Eugene Cernan]]]]
[[Image:NASA-Apollo8-Dec24-Earthrise.jpg|thumb|left|"Everything that I ever knew - my life, my loved ones, the Navy - everything, the whole world was behind my thumb." -[[Jim Lovell|James Lovell]]]]
Many [[astronaut]]s and [[astronaut|cosmonauts]] have commented on the profound effects that seeing Earth from space has had on them. One of the most important legacies of the Apollo program was the now-common, but not universal, 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]]<ref>{{cite web|author=[[Al Gore]]|url=http://forumpolitics.com/blogs/2007/03/17/an-inconvient-truth-transcript/|title=An Inconvenient Truth Transcript|date=[[2007-03-17]]|accessdate=2007-07-29|publisher=''Politics Blog'' -- a reproduction of the film's transcript}}</ref> .
===Documentaries===
There have been numerous documentary films covering the Apollo project and the space race.
* [[From the Earth to the Moon (miniseries)]], 1998
* [[For All Mankind]], 1989
* [[In the Shadow of the Moon]], 2007
* [[When We Left Earth]], 2008
==See also==
{{portal|Spaceflight|RocketSunIcon.svg}}
{{Commonscat}}
* [[Apollo Moon Landing hoax conspiracy theories]]
* [[Apollo TV camera]]
* [[Extra-vehicular activity]]
* [[List of artificial objects on the Moon]]
* [[Pad Abort Test-1 (Apollo)|Pad Abort Tests]]
* [[Soviet Moonshot]]
==Notes==
{{reflist|3}}
==References==
{{refbegin}}
* "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.
* {{cite book
| last =Hansen
| first =James R.
| title =Enchanted Rendezvous: John C. Houbolt and the Genesis of the Lunar-Orbit Rendezvous Concept
| publisher =NASA
| date =1995
| url =http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960014824_1996007704.pdf }}
*{{cite book
| last =Launius
| first =Roger
| authorlink =
| coauthors =Howard McCurdy
| title =Spaceflight and the Myth of Presidential Leadership
| publisher =University of Illinois Press
| date =1997
| location =Urbana }}
* {{cite book| first = Charles | last = Murray | coauthors =Catherine Bly Cox | title = Apollo: The Race to the Moon | location = New York | publisher = Simon and Schuster | year = 1989 | id = ISBN 0-671-61101-1}}
* {{cite journal | last =Papike| first= James|coauthors= Graham Ryder and Charles Shearer | title = Lunar Samples | journal = Reviews in Mineralogy and Geochemistry | volume = 36 | pages = 5.1–5.234 | date = 1998 }}
*{{cite book
| last =Sidey
| first =Hugh
| title =John F. Kennedy, President
| publisher =Atheneum
| date =1963
| location = New York }}
* {{cite book
| last = Swenson, Jr.
| first = Loyd S.
| coauthors = Courtney G Brooks and James M. Grimwood
| title = Chariots for Apollo: A History of Manned Lunar Spacecraft
| publisher = NASA
| date = 1979
| url = http://www.hq.nasa.gov/office/pao/History/SP-4205/contents.html}}
{{refend}}
==Further reading==
{{refbegin}}
* [[Gene Kranz|Kranz, Gene]], ''Failure is Not an Option''. Factual, from the standpoint of a chief flight controller during the [[Project Mercury|Mercury]], [[Project Gemini|Gemini]], and Apollo space programs. ISBN 0-7432-0079-9
* Chaikin, Andrew. ''A Man on the Moon''. ISBN 0-14-027201-1. Chaikin has interviewed all the surviving [[astronaut]]s, plus many others who worked with the program.
* 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.
* 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.
* Pellegrino, Charles R.; Stoff, Joshua. ''Chariots for Apollo: The Untold Story Behind the Race to the Moon''. ISBN 0-380-80261-9. Tells [[Grumman Aerospace Corporation|Grumman's]] story of building the Lunar Modules.
* [[Jim Lovell|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.
* [[Michael Collins (astronaut)|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
* [[Richard W. Orloff|Orloff, Richard W.]] [http://history.nasa.gov/SP-4029/SP-4029.htm SP-4029 ''Apollo by the Numbers: A Statistical Reference'']
* [[Deke Slayton|Slayton, Donald K.]]; Cassutt, Michael. ''Deke! An Autobiograpy''. 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.
* {{PDFlink|[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690022643_1969022643.pdf The Apollo spacecraft. Volume 1 - A chronology:]|13.2 [[Mebibyte|MiB]]<!-- application/pdf, 13893188 bytes -->}} From origin to [[7 November]], [[1962]]
* {{PDFlink|[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740004394_1974004394.pdf The Apollo spacecraft: Volume 2 - A chronology:]|13.4 [[Mebibyte|MiB]]<!-- application/pdf, 14117461 bytes -->}} [[8 November]] [[1962]] - [[30 September]] [[1964]]
* {{PDFlink|[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760014180_1976014180.pdf The Apollo spacecraft: Volume 3 - A chronology:]|57.7 [[Mebibyte|MiB]]<!-- application/pdf, 60504733 bytes -->}} [[1 October]] [[1964]] - [[20 January]] [[1966]]
* {{PDFlink|[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19800011953_1980011953.pdf The Apollo spacecraft: Volume 4 - A chronology:]|24.2 [[Mebibyte|MiB]]<!-- application/pdf, 25389552 bytes -->}} [[21 January]] [[1966]] - [[13 July]] [[1974]]
* {{PDFlink|[http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750013242_1975013242.pdf Apollo program summary report: Synopsis of the Apollo program - NASA report]|26.5 [[Mebibyte|MiB]]<!-- application/pdf, 27842805 bytes -->}}
{{refend}}
==External links==
* [http://spaceflight.nasa.gov/history/apollo/index.html Official Apollo program website]
* [http://spaceflight.nasa.gov/gallery/images/apollo/index.html Apollo photo gallery at NASA Human Spaceflight website] (includes videos/animations)
* [http://tapes.millercenter.virginia.edu/clips/1962_1121_apollo/ 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)
* [http://www.spaceflighthistory.com/apolloprogram.htm U.S. Spaceflight History- Apollo Program]
* [http://www.lpi.usra.edu/resources/apollo/ Apollo Image Atlas] almost 25,000 lunar images, Lunar and Planetary Institute
* [http://history.nasa.gov/apollo.html Project Apollo at NASA History Division]
* [http://www.hq.nasa.gov/alsj/frame.html The Apollo Lunar Surface Journal]
* [http://history.nasa.gov/afj/ The Apollo Flight Journal]
* [http://history.nasa.gov/diagrams/apollo.html Project Apollo Drawings and Technical Diagrams]
* [http://history.nasa.gov/apsr/apsr.htm Apollo Program Summary Report (Technical)]
* [http://www.nasm.si.edu/collections/imagery/Apollo/Apollo.htm The Apollo Program (National Air and Space Museum)]
* [http://www.nasa.gov/externalflash/apollo11/index1.html Apollo 35th Anniversary Interactive Feature] (in [[Adobe Flash|Flash]])
* [http://www.lpi.usra.edu/expmoon/apollo_landings.html Exploring the Moon: Apollo Missions]
* [http://www.apolloarchive.com/ Apollo Archive] - large repository of information about the Apollo program.
* [http://apollo.sese.asu.edu/ Apollo Flight Film Archive] - repository of scanned Apollo flight film (in high resolution).
* [http://history.nasa.gov/series95.html NASA History Series Publications] (many of which are on-line)
* [http://www.sti.nasa.gov/tto/apollo.htm Apollo's Contributions to Society]
==Related content==
{{Apollo program}}
{{US manned space programs | before=[[Project Gemini|Gemini]] | after=[[Skylab]]}}
{{NASA planetary exploration programs}}
{{NASA Spinoff}}
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[[Category:Apollo program| ]]
[[Category:Exploration of the Moon]]
[[Category:Engineering projects|Apollo]]
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