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For other meanings, see Apollo (disambiguation).

Project Apollo was a series of human spaceflight missions undertaken by the National Aeronautics and Space Administration (NASA) using the Apollo spacecraft and Saturn launch vehicle, conducted during the years 1961–1975. Developed by North American Aviation, 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 2006, 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.

Despite the successes, there were several major failures, most notably the deaths of astronauts Virgil Grissom, Ed White and Roger Chaffee in the Apollo 1 launchpad fire, the explosion on Apollo 13 which nearly killed three other astronauts, and a release of poisonous gases during re-entry of the Apollo-Soyuz Test Project spacecraft that nearly killed three more.

The Apollo project was named after the Greek god of the sun.

Background

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..."John F. Kennedy, "Special Message to the Congress on Urgent National Needs", May 25 1961

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."

The Apollo program was at least partly motivated by psycho-political considerations, in the context of the Cold War and the Space Race.

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.

Four possible plans were considered.

  • 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 far more powerful rocket than the most powerful proposed at the time, the Nova rocket.
  • Earth Orbit Rendezvous: This plan, known as Earth orbit rendezvous (EOR), would have required the launch of two Saturn V rockets, one containing the spaceship 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 Surface Rendezvous: This would have required two spacecraft to be launched - the first one, being an automated vehicle carrying propellants, would land on the Moon, to 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: 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; originally Lunar Excursion Module {LEM}). 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.

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 number 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.

Spacecraft

The Apollo spacecraft consisted of three main sections, plus two minor sections.

The Command Module (CM) was the part in which the astronauts spent most of their time, including launch and landing. It was the only part that returned to Earth after the mission. The Service Module (SM) housed the equipment needed by the astronauts, such as oxygen tanks, and the engine that would take the spacecraft into and out of lunar orbit. The combined Command and Service modules were called the CSM.

The Lunar Module (LM) (also known as Lunar Excursion Module, or LEM), was the part of the spacecraft that actually landed on the moon. It was comprised of two stages, one for descent, and one for ascent.

The Launch Escape Tower (LET) would carry the Command Module clear of the launch vehicle, should it explode during launch, and the Spacecraft Lunar Module Adapter (SLA) was used to connect the spacecraft to the Launch Vehicle. In addition, on Apollos 9 - 17, it housed and protected the Lunar Module and on the ASTP flight, it housed the docking adapter.

Astronauts

The following astronauts flew Apollo missions:

From the Mercury Seven

From Astronaut Group 2

From Astronaut Group 3

From Astronaut Group 4

From Astronaut Group 5

In addition, the following astronauts flew on Post-Apollo missions using Apollo hardware:

From the Mercury Seven

From Astronaut Group 4

From Astronaut Group 5

Missions

The Apollo program used four types of launch vehicles:

The 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 missions

Saturn I
||AS-108
Mission LV Serial No Launch Date Launch Time Remarks
SA-1 S-101 October 27, 1961 15:06 GMT Test of the Saturn 1 Rocket
SA-2 S-102 April 25, 1962 14:00 GMT Test of the S-1 Rocket and carried 109 m³ of water into the upper atmosphere to investigate effects on radio transmission and changes in local weather conditions.
SA-3 AS-103 November 16, 1962 17:45 GMT Repeat of the SA-2 mission.
SA-4 AS-104 March 28, 1963 20:11 GMT Test effects of premature engine shutdown
SA-5 AS-105 January 29, 1964 16:25 GMT First flight of live second stage
A-101 AS-106 May 28, 1964 17:07 GMT Tested the structural integrity of a boilerplate Apollo Command and Service Module
A-102 AS-107 September 18, 1964 17:22 GMT Carried the first programmable computer on the Saturn I vehicle; last test flight
A-103 AS-109 February 16, 1965 14:37 GMT Carried Pegasus A micrometeorite satellite plus a CSM boilerplate
May 25, 1965 07:35 GMT Carried Pegasus B micrometeorite satellite plus a CSM boilerplate
A-105 AS-110 July 30, 1965 13:00 GMT Carried Pegasus C micrometeorite satellite plus a CSM boilerplate

Pad abort tests
Mission Launch Date Launch Time Remarks
Pad Abort Test-1 November 7, 1963 16:00 GMT Launch Escape System (LES) abort test from launch pad.
Pad Abort Test-2 June 29, 1965 13:00 GMT LES pad abort test of near Block-I CM.

Little Joe II
Mission LV Serial No Launch Date Launch Time Remarks
QTV August 28, 1963 13:05 GMT Little Joe II qualification test.
A-001 May 13, 1964 13:00 GMT LES transonic abort test.
A-002 December 8, 1964 15:00 GMT LES maximum altitude, Max-Q abort test.
A-003 May 19, 1965 13:01 GMT LES canard maximum altitude abort test.
A-004 January 20, 1966 15:17 GMT LES test of maximum weight, tumbling Block-I CM.

Unmanned Apollo-Saturn IB and Saturn V
Mission Rocket LV Serial No Launch Date Launch Time Remarks
AS-201 Saturn IB AS-201 February 26, 1966 16:12 GMT First test flight of Saturn IB rocket
AS-203 Saturn IB AS-203 July 5, 1966 14:53 GMT Investigated effects of weightlessness on fuel tanks of S-IVB
AS-202 Saturn IB AS-202 August 25, 1966 17:15 GMT Sub-orbital test flight of Command and Service Module
Apollo 4 Saturn V AS-501 November 9, 1967 12:00 GMT First test of the Saturn V booster
Apollo 5 Saturn IB AS-204 January 22, 1968 22:48 GMT Test of the Saturn IB booster and Lunar Module
Apollo 6 Saturn V AS-502 April 4, 1968 16:12 GMT Test of the Saturn V booster
Skylab 1 Saturn INT-21 AS-513 May 14, 1973 17:30 GMT Unmanned launch of Skylab 1 workshop using Saturn INT-21 (two-stage version of the Saturn V booster). Last flight of Saturn V booster.

Manned missions

Mission Rocket LV Serial No Commander Senior Pilot Pilot CM Name LM Name Launch Date Launch Time Duration
Apollo 1 Saturn IB AS-204 Grissom White Chaffee N/A No LM February 21, 1967 (Planned) N/A N/A
Unlaunched - On January 27, 1967 Gus Grissom, Edward White, and Roger Chaffee are killed when fire erupts in their Apollo spacecraft during a test on the launch pad.
Mission Rocket LV Serial No Commander CM Pilot LM Pilot CM Name LM Name Launch Date Launch Time Duration
Apollo 7 Saturn IB AS-205 Schirra Eisele Cunningham N/A No LM October 11, 1968 15:02 GMT 10d 20h
09m 03s
First manned Apollo flight, first manned flight of the Saturn IB.
Apollo 8 Saturn V AS-503 Borman Lovell Anders N/A No LM December 21, 1968 12:51 GMT 06d 03h
00m 42s
First manned flight around the Moon, first manned flight of the Saturn V.
Apollo 9 Saturn V AS-504 McDivitt Scott Schweickart Gumdrop Spider March 3, 1969 16:00 GMT 10d 01h
00m 54s
First manned flight of the Lunar Module.
Apollo 10 Saturn V AS-505 Stafford Young Cernan Charlie Brown Snoopy May 18, 1969 16:49 GMT 08d 00h
03m 23s
First manned flight of the Lunar Module around the Moon.
Apollo 11 Saturn V AS-506 Armstrong Collins Aldrin Columbia Eagle July 16, 1969 13:32 GMT 08d 03h
18m 35s
First manned landing on the Moon, July 20.
Apollo 12 Saturn V AS-507 Conrad Gordon Bean Yankee Clipper Intrepid November 14, 1969 16:22 GMT 10d 04h
36m 24s
First precise manned landing on the Moon. Recovered part of Surveyor 3 probe.
Apollo 13 Saturn V AS-508 Lovell Swigert Haise Odyssey Aquarius April 11, 1970 19:13 GMT 05d 22h
54m 41s
Oxygen tank exploded en route, forcing cancellation of landing.
First (and, as of 2006, only) manned non-orbital lunar flight.
Apollo 14 Saturn V AS-509 Shepard Roosa Mitchell Kitty Hawk Antares January 31, 1971 21:03 GMT 09d 00h
01m 58s
Alan Shepard, the sole astronaut of the Mercury MR-3 mission - and thus the first American in space - walks on the Moon.
Apollo 15 Saturn V AS-510 Scott Worden Irwin Endeavour Falcon July 26, 1971 13:34 GMT 12d 07h
11m 53s
First mission with the Lunar Rover vehicle.
Apollo 16 Saturn V AS-511 Young Mattingly Duke Casper Orion April 16, 1972 17:54 GMT 11d 01h
51m 05s
First landing in the lunar highlands.
Apollo 17 Saturn V AS-512 Cernan Evans Schmitt America Challenger December 7, 1972 05:33 GMT 12d 13h
51m 59s
Final Apollo lunar mission, first night launch, only mission with a professional geologist.
The original pre-lunar landing program was more conservative but, as the 'all-up' test flights for the Saturn V proved successful, some 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 lunar missions

Mission name/designation Commander CM Pilot LM Pilot Mission date Date of cancellation
Apollo 18 Haise Pogue Carr February 1972 September 2, 1970
Budget cuts - NOTE: The Apollo 15 designation was re-used as Apollo 16 became 15, 17 became 16, and 18 became 17.
Apollo 19 Gordon Brand Schmitt July 1972 September 2, 1970
Budget cuts
Apollo 20 Roosa Lousma Lind December 1972 January 4, 1970
Launch vehicle needed to launch Skylab

Post-Apollo missions using Apollo hardware and Saturn IB
Mission Rocket LV Serial No Commander Pilot Science Pilot Launch Date Launch Time Duration
Skylab 2 Saturn IB AS-206 Conrad Weitz Kerwin May 25, 1973 13:00 GMT 28d 00h
49m 49s
First crew of the Skylab Space Station.
Skylab 3 Saturn IB AS-207 Bean Lousma Garriott July 28, 1973 11:10 GMT 59d 11h
09m 34s
Second Skylab crew. SM thruster malfunction nearly necessitated a Rescue Mission.
Skylab 4 Saturn IB AS-208 Carr Pogue Gibson November 16 1973 14:01 GMT 84d 01h
15m 31s
Third and final Skylab crew. Penultimate flight of Apollo.
Mission Rocket LV Serial No Commander CM Pilot Docking Module Pilot Launch Date Launch Time Duration
Apollo-Soyuz Test Project (Apollo 18) Saturn IB AS-209 Stafford Brand Slayton July 15 1975 12:20 GMT 05d 22h
30m 54s
Final flight of both Apollo and the Saturn Ib. Rendezvous and docking with Soyuz 19 spacecraft.

Launch Complex utilization

Samples Returned

Lunar
Mission 		Sample
Returned
Apollo 11 22 kg
Apollo 12 34 kg
Apollo 14 43 kg
Apollo 15 77 kg
Apollo 16 95 kg
Apollo 17 111 kg

Apollo returned 381.7kg (841.5 lb) of rocks and other material from the Moon; much 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 the Earth, as measured by radiometric dating techniques. The youngest of the rocks is older than most rocks seen on Earth. They range in age from 3.2 billion years from the basalt samples from the lunar mare, up to 4.6 billion years in the highlands. As such they represent samples from a very early period in the formation of the Solar System.

One of the most important rocks found during the Apollo Program was the Genesis Rock, retrived by astronauts James Irwin and David Scott of Apollo 15. The rock dates back to the formation of the moon.

Many of the rocks appear to be littered with micrometeoroid impact craters, something which is never seen on earth due to the thick atmosphere, but which is possible on the moon.

Apollo Applications

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 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.

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 unnamed 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.

In 1964/5 Grumman, the primary contrator for the Apollo LM systems, attempted to interest the USAF and Navy in a military version of CSM/LM configuration. The LM would have been equipped with a manipulator arm and projectile weapons to intercept and disable enemy satellites. The proposal was never fully developed and was abandoned in 1967.

End of the program

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 decisio

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Project Apollo".

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