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 the American spaceflight endeavor which 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.^[1][2]

This goal was accomplished during 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.^[3]

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

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."^[4] While NASA went ahead with planning for Apollo, funding for the program was far from certain given Eisenhower's ambivalent attitude to manned spaceflight.^[5]

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."^[6] 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.^[7] 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.^[8]

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.^[9] Kennedy, however, was circumspect in his response to the news, refusing to make a commitment on America's response to the Soviets.^[10] 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.^[11] 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."^[12] 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.^[12]

On May 25, 1961, Kennedy announced his support for the Apollo program as part of a special address to a joint session of Congress:^[1]

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.^[2]

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.^[13]

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^[14]

Choosing a mission mode

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)

• 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.^[15]

Seamans' establishment of the Golovin committee in July 1961 represented a turning point in NASA's mission mode decision.^[16] 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.^[16] 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^[17]

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

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

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 cylindrical 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.^[18] 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."^[19]

Lunar Module

Apollo LM on lunar surface

The Lunar Module (LM) (originally known as the Lunar Excursion Module, or LEM), was designed to fly between lunar orbit and the surface, landing two astronauts on the Moon and taking them back 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 through the Earth's atmosphere, or even stand up under Earth's gravity, which is six times stronger than the Moon's. It consisted of two stages, a descent and an ascent stage. The descent stage contained compartments which carried cargo such as the Apollo Lunar Surface Experiment Package and Lunar Rover.

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.^[20] 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 I, Saturn IB and Saturn V. While the Saturn V was less powerful than the Nova would have been, it was still much more powerful than any rocket developed before, or since. (The USSR N1 was approximately as powerful, but it was never successful.)

Saturn IB

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

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 (730,000 N) 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 (102,000 N) 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.^[21] It was used in five of the Apollo test missions including the first manned mission. It was also used in the manned missions for the Skylab program and the Apollo-Soyuz Test Project.

Saturn V

The Saturn V rocket launches Apollo 11 in 1969

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 (3,400,000 N) 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).^[22]
• 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).^[23]
• An S-IVB-500 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.^[24]
• An instrument unit with a guidance system similar to that used on the Saturn IB.

Three Saturn V vehicles launched on Earth orbital flights. Two of the three (Apollo 4 and 6) were unmanned tests of the command and service modules, and the third was a manned flight, Apollo 9, testing the lunar module. Nine Saturn Vs launched manned Apollo missions to the Moon, including Apollo 11. It was also used for the unmanned launch of Skylab.

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.

Capsule Communicator (CAPCOM)

Mission rules specified that, in most circumstances, only one person in the Mission Control Center would communicate directly with the in-flight crew, and that this was to be another astronaut, who would be best able to understand the situation in the spacecraft and communicate with the crew in the clearest way. These individuals were designated Capsule Communicators or CAPCOMs, a term carried over from the Mercury and Gemini programs. They were usually chosen from the backup and support crews, and worked in shifts during long missions.

The periodic beeps heard during communications with the astronauts are known as Quindar tones.

Missions

Mission types

see List of Apollo mission types

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.^[25] The simple numbering was started at "4" due to the previous three 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.^[26] 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

The manned missions always carried three astronauts, designated as Commander, Command Module Pilot (CMP), and Lunar Module Pilot (LMP). Besides exercising all crew command decisions, the Commander was the primary pilot of both spacecraft (when present) and was first to exit the LM on the surface of the Moon. The CMP functioned as navigator, usually performed the initial docking with the LM, and remained in the Command/Service Module when his companions flew the LM. The LMP functioned as engineering officer, monitoring the systems of both spacecraft. On a landing mission, he accompanied the Commander on the lunar surface. On the last flight, the LMP was a professional geologist, Dr. Harrison Schmitt.

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.

Between December 21, 1968 and May 18, 1969, NASA planned to launch three manned test / practice missions using the Saturn V launch vehicle and the complete spacecraft including the LM. But by the summer of 1968 it became clear to program managers that a fully functional LM would not be available for the Apollo 8 launch. Rather than waste the Saturn V on another simple Earth-orbiting mission, they chose to send the crew planned to make the second orbital LM test in Apollo 9, to orbit the Moon in the CSM on Apollo 8 during Christmas. The original idea for this switch was the brainchild of George Low, Manager of the Apollo Spacecraft Program Office. 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.

This was followed by the first orbital manned LM flight on Apollo 9 (with the original Apollo 8 crew), and the lunar "dress rehearsal" Apollo 10 which took the LM to within 50,000 feet (15 km) of the surface, but did not land.

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

—Neil Armstrong^[27]

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

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 30 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 re-entered the atmosphere 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

Samples returned

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.
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.^[29] 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.^[30]

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.^[31] 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.^[32]

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 procurement of 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 September 2004.^[31]

Canceled 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.^[33][34] 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.

Influence on future human space exploration

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

On January 14, 2004, President George W. Bush announced a new Vision for Space Exploration, which included plans for the Constellation program, which would return US astronauts to the Moon no later than 2020. This program was to use a new generation of manned spacecraft and launch vehicles, including: the Orion spacecraft, similar to Apollo's CSM with a larger crew; an Altair lunar lander; an Earth Departure Stage analogous to the S-IVB; and Ares 1 and Ares V launch vehicles.

However, in February 2010 President Barack Obama excluded Constellation from his administration's proposed 2011 United States federal budget, which as of May 2010 is still subject to congressional approval.^[35][36]

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 crew of Apollo 8, the first manned spacecraft to orbit the Moon, sent televised pictures of the Earth and the Moon back to Earth, and read from the creation story in the Biblical book of Genesis, on Christmas Eve, 1968, This was believed to be the most widely watched television broadcast up until that time. The mission and Christmas provided an inspiring end to 1968, which had been a bad year for the United States, marked by Vietnam War protests, race riots, and the assassinations of Martin Luther King and Senator Bobby Kennedy.

An estimated one-fifth of the population of the world watched the live transmission of the first Apollo Moonwalk.^[37]

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.^[38] 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.^[39]

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^[39]

The Moon landing data was recorded by a special Apollo TV camera which recorded in a format that was not 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.^[39]

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^[39]

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.^[40]

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^[39]

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.^[40]

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.^[41]

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^[42]

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.^[43]

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.^[44][45]

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^[42]

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.^[46]

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 TV camera
• List of artificial objects on the Moon
• Pad Abort Tests
• Soviet Moonshot

Notes

References

Further reading

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?
• Hidden Space Project Article about critics on Apollo 11.

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