Apollo program

Apollo program
Apollo program.svg
CountryUnited States
PurposeCrewed lunar landing
Program history
  • $25.4 billion (1973)[1]
  • $153 billion (2018)[2]
First flight
  • SA-1
  • October 27, 1961 (1961-10-27)
First crewed flight
  • Apollo 7
  • October 11, 1968 (1968-10-11)
Last flight
Failures2 (Apollo 1 and 13)
Partial failures1 (Apollo 6)
Launch site(s)
Vehicle information
Crew vehicle
Launch vehicle(s)

The Apollo program, also known as Project Apollo, was the third United States human spaceflight program carried out by the National Aeronautics and Space Administration (NASA), which succeeded in landing the first humans on the Moon from 1969 to 1972. First conceived during Dwight D. Eisenhower's administration as a three-person spacecraft to follow the one-person Project Mercury which put the first Americans in space, Apollo was later dedicated to the national goal set by President John F. Kennedy of "landing a man on the Moon by the end of this decade and returning him safely to the Earth" in an address to Congress on May 25, 1961. It was the third US human spaceflight program to fly, preceded by the two-person Project Gemini conceived in 1961 to extend spaceflight capability in support of Apollo.

Kennedy's goal was accomplished on the Apollo 11 mission when astronauts Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module (LM) on July 20, 1969, and walked on the lunar surface, while Michael Collins remained in lunar orbit in the command and service module (CSM), and all three landed safely on Earth on July 24. Five subsequent Apollo missions also landed astronauts on the Moon, the last in December 1972. In these six spaceflights, twelve men walked on the Moon.

Astronaut Buzz Aldrin stands on the Moon
Buzz Aldrin (pictured) walked on the Moon with Neil Armstrong, on Apollo 11, July 20–21, 1969
Earthrise, an iconic image from the 1968 Apollo 8 mission, taken by astronaut William Anders

Apollo ran from 1961 to 1972, with the first crewed flight in 1968. It achieved its goal of crewed lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a prelaunch test. After the first landing, sufficient flight hardware remained for nine follow-on landings with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but the Apollo 13 landing was prevented by an oxygen tank explosion in transit to the Moon, which destroyed the service module's capability to provide electrical power, crippling the CSM's propulsion and life support systems. The crew returned to Earth safely by using the lunar module as a "lifeboat" for these functions. Apollo used Saturn family rockets as launch vehicles, which were also used for an Apollo Applications Program, which consisted of Skylab, a space station that supported three crewed missions in 1973–74, and the Apollo–Soyuz Test Project, a joint US-Soviet Union Earth-orbit mission in 1975.

Apollo set several major human spaceflight milestones. It stands alone in sending crewed missions beyond low Earth orbit. Apollo 8 was the first crewed spacecraft to orbit another celestial body, while the final Apollo 17 mission marked the sixth Moon landing and the ninth crewed mission beyond low Earth orbit. The program returned 842 pounds (382 kg) of lunar rocks and soil to Earth, greatly contributing to the understanding of the Moon's composition and geological history. The program laid the foundation for NASA's subsequent human spaceflight capability and funded construction of its Johnson Space Center and Kennedy Space Center. Apollo also spurred advances in many areas of technology incidental to rocketry and human spaceflight, including avionics, telecommunications, and computers.


Origin and spacecraft feasibility studies

The Apollo program was conceived during the Eisenhower administration in early 1960, as a follow-up to Project Mercury. While the Mercury capsule could only support one astronaut on a limited Earth orbital mission, Apollo would carry three astronauts. Possible missions included ferrying crews to a space station, circumlunar flights, and eventual crewed lunar landings.

The program was named after Apollo, the Greek god of light, music, and the Sun, by NASA manager Abe Silverstein, who later said that "I was naming the spacecraft like I'd name my baby."[3] Silverstein chose the name at home one evening, early in 1960, because he felt "Apollo riding his chariot across the Sun was appropriate to the grand scale of the proposed program."[4]

In July 1960, NASA Deputy Administrator Hugh L. Dryden announced the Apollo program to industry representatives at a series of Space Task Group conferences. Preliminary specifications were laid out for a spacecraft with a mission module cabin separate from the command module (piloting and reentry cabin), and a propulsion and equipment module. On August 30, a feasibility study competition was announced, and on October 25, three study contracts were awarded to General Dynamics/Convair, General Electric, and the Glenn L. Martin Company. Meanwhile, NASA performed its own in-house spacecraft design studies led by Maxime Faget, to serve as a gauge to judge and monitor the three industry designs.[5]

Political pressure builds

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. Up to the election of 1960, Kennedy had been speaking out against the "missile gap" that he and many other senators felt had developed between the Soviet Union and United States due to the inaction of President Eisenhower.[6] Beyond military power, Kennedy used aerospace technology as a symbol of national prestige, pledging to make the US not "first but, first and, first if, but first period".[7] Despite Kennedy's rhetoric, he did not immediately come to a decision on the status of the Apollo program once he became president. He knew little about the technical details of the space program, and was put off by the massive financial commitment required by a crewed Moon landing.[8] When Kennedy's newly appointed NASA Administrator James E. 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.[9]

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 US House Committee on Science and Astronautics one day after Gagarin's flight, many congressmen pledged their support for a crash program aimed at ensuring that America would catch up.[10] Kennedy was circumspect in his response to the news, refusing to make a commitment on America's response to the Soviets.[11]

President John F. Kennedy addresses a joint session of Congress, with Vice President Lyndon B. Johnson and House Speaker Sam Rayburn seated behind him
President Kennedy delivers his proposal to put a man on the Moon before a joint session of Congress, May 25, 1961

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.[12][13] 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."[14][15] His memo concluded that a crewed Moon landing was far enough in the future that it was likely the United States would achieve it first.[14]

On May 25, 1961, twenty days after the first US crewed spaceflight Freedom 7, Kennedy proposed the crewed Moon landing in a Special Message to the Congress on Urgent National Needs:

Now it is time to take longer strides - time for a great new American enterprise - time for this nation to take a clearly leading role in space achievement, which in many ways may hold the key to our future on Earth.

...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.[16] Full text Wikisource has information on "Special Message to the Congress on Urgent National Needs"

Other Languages
Afrikaans: Apollo-program
العربية: برنامج أبولو
aragonés: Programa Apollo
asturianu: Programa Apollo
azərbaycanca: Apollon proqramı
Bân-lâm-gú: Apollo kè-ōe
беларуская (тарашкевіца)‎: Апалён (касьмічная праграма)
български: Аполо
brezhoneg: Programm Apollo
čeština: Program Apollo
español: Programa Apolo
Esperanto: Projekto Apollo
français: Programme Apollo
Gaeilge: Clár Apollo
한국어: 아폴로 계획
hrvatski: Program Apollo
Bahasa Indonesia: Program Apollo
Кыргызча: «Аполлон»
latviešu: Apollo programma
Lëtzebuergesch: Apollo-Programm
lietuvių: Apollo
Limburgs: Apollo-program
Bahasa Melayu: Program Apollo
Mirandés: Porjeto Apollo
မြန်မာဘာသာ: အပိုလိုစီမံကိန်း
Nederlands: Apolloprogramma
日本語: アポロ計画
norsk nynorsk: Apollo-programmet
oʻzbekcha/ўзбекча: Apollon (kosmik kema)
Piemontèis: Programa Apollo
Plattdüütsch: Apollo-Programm
português: Programa Apollo
Simple English: Apollo program
slovenčina: Program Apollo
slovenščina: Program Apollo
српски / srpski: Пројекат Аполо
srpskohrvatski / српскохрватски: Program Apollo
Türkçe: Apollo Projesi
Tiếng Việt: Chương trình Apollo