The Apollo program was the culmination of arguably the largest and highest profile single technological endeavour the human race has ever embarked upon.
The United States, in the form of the National Aeronautics and Space Administration (NASA), won the race to the moon when the Apollo 11 mission touched down in the Sea of Tranquility on 20 July 1969, achieving and surpassing President John F Kennedy's 1961 goal of “landing a man on the moon” and bringing him safely back to Earth “by the end of this decade”.
On that momentous day, the 'Eagle' Lunar Excursion Module (LEM) delivered Neil Armstrong and Edwin Buzz Aldrin to the surface of the moon. “Houston. Tranquility base here. The Eagle has landed.” Six and a half hours later, Neil Armstrong descended the ladder of the LEM, and becoming the first human to stand on the surface of another world, uttered the words that have become engraved in not only space exploration history, but the history of the human race as a whole. “That's one small step for man, one giant leap for mankind.”
The Apollo program followed on from the Mercury and Gemini missions which put first one and then two astronauts into orbit around the Earth and paved the way for unmanned and then manned missions to the moon. The missions were launched from the Lyndon B Johnson Space Centre, and overseen by Flight Director Gene Kranz and a massive team of mission controllers.
The mighty Saturn I, Saturn IB, and ultimately the Saturn V rockets were used to lift the weight of the Command Module (CM), Service Module (SM) and the Lunar Module (LM, or Lunar Excursion Module (LEM)), into Earth orbit. The first missions, during the period February to August 1966, were designated Apollo-Saturn (AS), missions AS201, AS202 and AS203. These unmanned, suborbital missions tested and demonstrated, amongst many other things, the capability of the Saturn V rocket stages and the safety of the Command Module re-entry heat shield.
The AS204 mission, later officially named Apollo 1 in memory of its ill-fated crew, was due to be the first manned mission in February 1967. A multi Earth orbit mission, planned to further test the Command and Service Module (CSM), ended abruptly during a launch rehearsal on 27 January, when a still undetermined electrical fault caused a fatal fire in the pure oxygen atmosphere of the Command Module cabin, killing all three crew members, Virgil “Gus” Grissom, Edward 'Ed' White and Roger Chaffee. This terrible accident was a major setback for the Apollo program, and highlighted fundamental flaws in the safety design of the Command and Service Module.
Delayed by nine months following the Apollo 1 tragedy, November 1967 saw the launch of Apollo 4, which took it's designation of 4 following on from the original AS201, 202 and 203 missions, and was the first flight of the Saturn V rocket. An unmanned mission, and the first orbital flight for the Saturn V and the Command Service Module, it successfully demonstrated the third stage restart, and was the first test for the Command Module heat shield at lunar re-entry speed.
Apollo 5 (Saturn IB) and Apollo 6 (Saturn V) in January and April of 1968 respectively, were the first flights of the Lunar Module in Earth orbit, and successfully tested its descent and ascent engines and the landing or “fire in the hole” abort. Apollo 6 also successfully tested the trans-lunar injection program and the direct abort to high speed re-entry. Although severe vibrations during launch caused the Saturn V second stage engines to shut down prematurely and the third stage restart to fail, NASA declared the Saturn V as 'man-rated'.
Apollo 7 (Saturn V) was the first successful manned Apollo mission in October of 1968. The crew, Walter “Wally” Schirra, Donn Eisele and Walter Cunningham, completed the 11 day flight, including the first live television broadcast from a US space mission, and the Command Service Module completed its successful Earth orbital test.
Apollo 8 in December of 1968, crewed by Frank Borman, Jim Lovell and William A Anders, saw the Command Module successfully injected into lunar trajectory and they completed 10 orbits of the moon, becoming the first humans to see the far side, and to witness an Earth-rise with their own eyes. During this mission, the crew read from the Biblical book of Genesis on Christmas Eve. This is believed to have been the most widely watched television broadcast until that time. This flight took place, despite the Lunar Module not being ready for the first manned lunar orbital test.
Apollo 9, crewed by James McDivitt, David Scott and Russell 'Rusty' Schweickart in March of 1969, tested the Lunar Module propulsion and rendezvous/docking with CSM procedures. During 10 days in Earth orbit, and EVA (Extra-Vehicular Activity) outside the craft, the crew tested the lunar Portable Life Support System (PLSS), the space suits that Neil Armstrong and Buzz Aldrin would use during their lunar landing.
Apollo 10 in May 1969, was known as the 'dress rehearsal' for the lunar landing mission of Apollo 11. The crew, Thomas Stafford, John Young and Eugene Cernan successfully manned the Command Module in lunar orbit and took the Lunar Module to within 16.5 km (8.4 nautical miles) of the moons surface.
Apollo 11, July 1969, Neil Armstrong, Buzz Aldrin and Michael Collins. The first successful landing by Neil Armstrong and Buzz Aldrin on the moon, in the Sea of Tranquility. While Michael Collins remained in orbit in the Command Module, Neil Armstrong and Buzz Aldrin overcame navigation errors and computer alarms during the Lunar Module descent. The first men to set foot on the moon, watched by an estimated fifth of the population of the planet Earth at the time, they completed successful EVA, planting the flag of the USA at the landing site and collecting multiple samples of rocks and dust from the surface, before returning to a hero’s welcome.
Apollo 12 followed in November 1969 with Pete Conrad, Richard Gordon and Alan Bean. The first precision landing, in the Ocean of Storms near the Surveyor 3 probe landing site, saw parts of that probe being returned to Earth, an S-band antenna being deployed, their lunar camera accidentally being damaged by exposure to the sun, and scares during the first controlled lift off of the ascent stage after two lightning strikes briefly disabled the fuel cells and telemetry.
Apollo 13 in April of 1970 gripped the world as the landing mission was aborted following a Service Module oxygen tank explosion on the outward journey to the moon and the now famous rescue mission involving the crew, Jim Lovell, Jack Swigert and Fred Haise using the Lunar Module as a 'lifeboat' with incredible ingenuity and guidance from mission control staff to get them back to Earth safely after orbiting the moon.
Between January 1971 and December 1972, there followed four further successful manned Apollo missions to various locations on the moon's surface. Apollo 14 (Alan Shepard, Stuart Roosa, Edgar Mitchell). Apollo 15 (David Scott, Alfred Worden, James Irwin). Apollo 16 (John Young, Ken Mattingly, Charles Duke). Apollo 17 (Eugene Cernan, Ronald Evans, Harrison “Jack” Schmitt).
These missions included long stay (3 day) landings, with many lunar surface experiments and geological surveys and investigations, multiple EVAs including a deep space EVA, and notable and memorable events such as the use of the lunar rover, the first colour television pictures broadcast from the surface, and even Alan Shepard hitting the first golf ball on the moon. The missions also overcame multiple problems in ascent, docking and CSM yaw/gimbal equipment and instrumentation.
And so came to an end the Apollo lunar missions. Apollo 18, 19 and 20 were cancelled after shrinking NASA budgets and focus on the Space Shuttle program and Skylab made further missions to the moon a no go. Further production of Saturn V rockets was ceased, and the existing rockets and Apollo space craft were used in the Skylab programme, and despite years of planning and enormous cost in preparing for further trips to the moon, the US government has now also cancelled the Constellation program, intended to land man on the moon again by 2020.
The Apollo moon missions stimulated technological advance with the flight computer designs being the launch pad for early research into integrated circuits, and the development of advanced fuel cells, computer controlled machining and countless other areas of technological development.
The 24 astronauts that manned the Apollo missions are the only humans to ever have gone beyond low Earth orbit, and remain the 24 humans that have travelled farther from the planet Earth than any other.