Project Apollo

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For other meanings, see Apollo (disambiguation).
North American Apollo CSM
Apollo CSM in lunar orbit.
Apollo CSM in lunar orbit.
Role: Earth and lunar orbit
Crew: 3; CDR, CM pilot, LM pilot
Height: 36.2 ft 11.03 m
Diameter: 12.8 ft 3.9 m
Volume: 218 ft3 6.17 m3
Command module: 12,807 lb 5,809 kg
Service module: 54,064 lb 24,523 kg
Total: 66,871 lb 30,332 kg
Rocket engines
CM RCS (N2O4/UDMH) x 12: 92 lbf ea 412 N
SM RCS (N2O4/UDMH) x 16: 100 lbf ea 441 N
Service Propulsion System
(N2O4/UDMH) x 1:
22,000 lbf ea 97.86 kN
Endurance: 14 days 200 orbits
Apogee: 240,000 miles 386,242 km
Perigee: 100 miles 160 km
Spacecraft delta v: 9,200 ft/s
(6,272 mi/hr)
2,804 m/s
(10,094 km/h)
Apollo CSM diagram
Apollo CSM diagram (NASA)
Apollo CSM diagram (NASA)
North American Apollo CSM
File:Apollo program insignia.jpg
Apollo Program insignia

Project Apollo was a series of human spaceflight missions undertaken by the United States of America using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961–1972. It was devoted to the goal of landing a man on the Moon and returning him safely to Earth within the decade of the 1960s. This goal was achieved with the Apollo 11 mission in July 1969. The program continued into the early 1970s to carry out the initial hands-on scientific exploration of the Moon, with a total of six successful landings. As of 2005, there has not been any further human spaceflight beyond low earth orbit. The later Skylab program and the joint American-Soviet Apollo-Soyuz Test Project used equipment originally produced for Apollo, and are often considered to be part of the overall program. The name Apollo, like earlier manned space-flight programs, was named after a god from classical civilizations, and comes from one of the Greek gods.


The Apollo Program was originally conceived late in the Eisenhower administration as a follow-on to the Mercury program, doing advanced manned earth-orbital missions. In fact, it became the third program, following Gemini. The Apollo Program was dramatically reoriented to an aggressive lunar landing goal by President Kennedy with his announcement at a special joint session of Congress on May 25, 1961:

"...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..." (Excerpt from "Special Message to the Congress on Urgent National Needs" [1])

Choosing a mission mode

Having settled upon the Moon as a target, the Apollo mission planners were faced with the challenge of designing a set of flights that would meet Kennedy's stated goal while minimizing risk to human life, cost and demands on technology and astronaut skill.

Three possible plans were considered.

File:Apollo Direct Ascent.png
Apollo configuration for
Direct Ascent and
Earth Orbit Rendezvous - 1961 (NASA)
  • Direct ascent: This plan was to boost a spaceship directly to the moon. The entire spacecraft would land on and return from the moon. This would have required a Nova rocket far more powerful than any in existence at the time.
  • Earth orbit rendezvous: This plan, known as Earth orbit rendezvous (EOR), would have required the launch of two Saturn V rockets, one containing the space ship and one containing fuel. The spaceship would have docked in earth orbit and be fueled with enough fuel to make it to the moon and back. Again, the entire spacecraft would have landed on the moon.
  • Lunar orbit rendezvous: This plan, which was adopted, is credited to John Houbolt and used the technique of 'Lunar Orbit Rendezvous' (LOR). The spacecraft was modular, composed of a 'Command/Service Module' (CSM) and a 'Lunar Module' (LM; pronounced LEM, for Lunar Excursion Module, its initial name). The CSM contained the life support systems for the three man crew's five day round trip to the moon and the heat shield for their reentry to Earth's atmosphere. The LM would separate from the CSM in lunar orbit and carry two astronauts for the descent to the lunar surface, then back up to the CSM.

In contrast with the other plans, the LOR plan 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. The mass to be launched was further minimized by leaving part of the LM (that with the descent engine) behind, on the moon.

Grumman Apollo LM
Apollo LM on lunar surface.
Apollo LM on lunar surface.
Role: Lunar landing
Crew: 2; CDR, LM pilot
Height: 20.9 ft 6.37 m
Diameter: 14 ft 4.27 m
Landing gear span: 29.75 ft 9.07 m
Volume: 235 ft3 6.65 m3
Ascent module: 10,024 lb 4,547 kg
Descent module: 22,375 lb 10,149 kg
Total: 32,399 lb 14,696 kg
Rocket engines
LM RCS (N2O4/UDMH) x 16: 100 lbf ea 441 N
Ascent propulsion system
(N2O4/Aerozine 50) x 1:
3,500 lbf ea 15.57 kN
Descent propulsion system
(N2O4/Aerozine 50) x 1:
9,982 lbf ea 44.4 kN
Endurance: 3 days 72 hours
Apogee: 100 miles 160 km
Perigee: surface surface
Spacecraft delta v: 15,387 ft/s
(10,491 mi/h)
4,690 m/s
(16,884 km/h)
Apollo LM diagram
Apollo LM diagram (NASA)
Apollo LM diagram (NASA)
Grumman Apollo LM

The Lunar Module itself was composed of a descent stage and an ascent stage, the former serving as a launch platform for the latter when the lunar exploration party blasted off for lunar orbit where they would dock with the CSM prior to returning to Earth. The plan had the advantage that since the LM was to be eventually discarded, it could be made very light, so the moon mission could be launched with a single Saturn V rocket. However, at the time that LOR was decided, some mission planners were uneasy at the large numbers of dockings and undockings called for by the plan.

To learn lunar landing techniques, astronauts practiced in the Lunar Landing Research Vehicle (LLRV), a flying vehicle that simulated (by means of a special, additional jet engine) the reduced gravity that the Lunar Module would actually fly in.


The Apollo program included eleven manned flights, designated Apollo 7 through Apollo 17, all launched from the Kennedy Space Center, Florida. Apollo 4 through Apollo 6 were unmanned test flights (officially there was no Apollo 2 or Apollo 3). The Apollo 1 designation was retroactively applied to the originally planned first manned flight which ended in a disastrous fire during a launch pad test that killed three astronauts, "Gus" Grissom, Edward White, and Roger B. Chaffee, in January 1967. The first of the manned flights employed the Saturn IB launch vehicle; the remaining flights all used the more powerful Saturn V. Two of the flights (Apollo 7 and Apollo 9) were Earth orbital missions, two of the flights (Apollo 8 and Apollo 10) were lunar orbital missions, and the remaining 7 flights were lunar landing missions (although one, Apollo 13, failed to land).

Apollo 7 tested the Apollo command and service modules (CSM) in Earth orbit. Apollo 8 tested the CSM in lunar orbit. Apollo 9 tested the lunar module (LM) in earth orbit. Apollo 10 tested the LM in lunar orbit. Apollo 11 achieved the first human lunar landing. Apollo 12 achieved the first lunar landing at a precise location. Apollo 13 failed to achieve a lunar landing, but succeeded in returning the crew safely to earth following a potentially disastrous in-flight explosion. Apollo 14 resumed the lunar exploration program. Apollo 15 introduced a new level of lunar exploration capability, with a long-stay-time LM and a lunar roving vehicle. Apollo 16 was the first manned landing in the lunar highlands. Apollo 17, the final mission, was the first to include a scientist-astronaut, and the program's first manned night launch.

Apollo Applications Program

In the speech which initiated Apollo, Kennedy declared that no other program would have as great a long-range effect on America's ambitions in outer space. Following the success of Project Apollo, 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 at least ten flights. Many of these would use the space that the lunar module took up in the Saturn rocket to carry scientific equipment.

One plan involved using the Saturn IB to take the Command/Service Module (CSM) to a variety of low-earth orbits for missions lasting up to 45 days. Some missions would involve the docking of two CSMs, and transfer of supplies. The Saturn V would be necessary to take it to polar orbit, or sun-synchronous orbit (neither of which has yet been achieved by any manned spacecraft), and even to the geosynchronous orbit of Syncom 3, a communications satellite not quite in geostationary orbit. This was the first functioning communications satellite at that now-common great distance from the Earth, and it was small enough to be carried through the hatch and taken back to Earth for study as to the effects of radiation on its electronic components in that environment over a period of years. A return to the moon was also planned, this time to orbit for a longer time to map the surface with high-precision equipment. This mission would not include a landing.

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, 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 an un-named 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.

End of the program

Unflown command module CM-007 in a museum

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 cancelled 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 Saturn Vs was actually used; the others became museum exhibits.

Another excerpt from Kennedy's Special Message to Congress:

"I believe we should go to the moon. But I think every citizen of this country as well as the Members of the Congress should consider the matter carefully in making their judgment, to which we have given attention over many weeks and months, because it is a heavy burden, and there is no sense in agreeing or desiring that the United States take an affirmative position in outer space, unless we are prepared to do the work and bear the burdens to make it successful. If we are not, we should decide today and this year.
"This decision demands a major national commitment of scientific and technical manpower, material and facilities, and the possibility of their diversion from other important activities where they are already thinly spread. It means a degree of dedication, organization and discipline which have not always characterized our research and development efforts. It means we cannot afford undue work stoppages, inflated costs of material or talent, wasteful interagency rivalries, or a high turnover of key personnel.
"New objectives and new money cannot solve these problems. They could in fact, aggravate them further--unless every scientist, every engineer, every serviceman, every technician, contractor, and civil servant gives his personal pledge that this nation will move forward, with the full speed of freedom, in the exciting adventure of space." (Excerpt from "Special Message to the Congress on Urgent National Needs")

Reasons for Apollo

The Apollo program was at least partly motivated by psycho-political considerations, in response to persistent perceptions of American inferiority in space technology vis-a-vis the Soviets, in the context of the Cold War and the Space Race. In this respect it succeeded brilliantly. In fact, American superiority in manned spaceflight was achieved in the precursory Gemini program, even before the first Apollo flight.

The Apollo 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.

Many astronauts and 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." These photographs have also motivated many people toward environmentalism and space colonization.

Miscellaneous information

  • The cost of the entire Apollo program: USD $25.4 billion -1969 Dollars ($135-billion in 2005 Dollars). See NASA Budget. (Includes Mercury, Gemini, Ranger, Surveyor, Lunar Orbitar, Apollo programs.) Apollo spacecraft and Saturn rocket cost alone, was about $ 83-billion 2005 Dollars (Apollo spacecraft cost $ 28-billion (CS/M $ 17-billion; LM $ 11-billion), Saturn I, IB, V costs about $ 46-billion 2005 dollars).
  • Amount of moon material brought back by the Apollo program: 381.7 kg (841.5 lb). Most of the material is stored at the Lunar Receiving Laboratory in Houston.


The Apollo program used four types of launch vehicles:

Something to note with Apollo flights is that Marshall Space Flight Center, which designed the Saturn rockets, referred to the flights as Saturn-Apollo (SA), while Kennedy Space Center referred to the flights as Apollo-Saturn (AS). This is why the unmanned Saturn 1 flights are referred to as SA and the unmanned Saturn 1B are referred to as AS.

Dates given below are dates of launch.

Unmanned Saturn I

Unmanned pad abort tests

File:Pad Abort Launch.jpg
Pad Abort Test (NASA)

Unmanned Little Joe II

Unmanned Apollo-Saturn IB and Saturn V


The original pre-lunar landing program was more conservative but as the 'all-up' test flights for the Saturn V proved successful missions were deleted. The revised schedule published in October 1967 had the first manned Apollo CSM earth orbit mission (Apollo 7) followed by an Earth Orbit Rendezvous of the CSM and LM launched on two Saturn 1Bs (Apollo 8) followed by a Saturn V launched CSM on a Large Earth Orbit Mission (Apollo 9) followed by the Saturn V launched dress rehearsal in Lunar Orbit with Apollo 10. By the summer of 1968 it became clear to program managers that a fully functional LM would not be available for the Apollo 8 mission. Rather than perform a simple earth orbiting mission, they chose to send Apollo 8 around the moon during Christmas. The original idea for this switch was the brainchild of George Low. Although it has often been claimed that this change was made as a direct response to Soviet attempts to fly a piloted Zond spacecraft around the moon, there is no evidence that this was 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.

Cancelled missions

Main article: Cancelled Apollo missions
  • Apollo 18
  • Apollo 19
  • Apollo 20

Later missions using left over Apollo hardware

Apollo Launch Complex utilization

See also

Template:US manned space programs


External links

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