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Moon landing



 
 
A moon landing is the arrival of an intact manned or unmanned spacecraft
Spacecraft

A spacecraft is a Craft or machine designed for spaceflight. On a sub-orbital spaceflight, a spacecraft enters outer space then returns to the Earth....
 on the surface of a planet
Planet

A planet , as 2006 definition of planet by the International Astronomical Union , is a celestial body orbiting a star or Stellar evolution#Stellar remnants that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared the neighbourhood of planetesimals....
's natural satellite
Natural satellite

A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called the primary. Technically, the term natural satellite could refer to a planet orbiting a star, or a dwarf galaxy orbiting a major galaxy, but it is normally synonymous with moon and used to identify non-artificial satellites...
. The concept has been a goal of humankind since it was first appreciated that the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
 is Earth
Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
's closest large celestial body. One of the clearest early examples of the concept in fiction was Jules Verne
Jules Verne

Jules Gabriel Verne was a France author who helped pioneer the science fiction genre. He is best known for his novels Journey to the Center of the Earth , From the Earth to the Moon , Twenty Thousand Leagues Under the Sea , and Around the World in Eighty Days ....
's novel From the Earth to the Moon
From the Earth to the Moon

From the Earth to the Moon is a humorous science fantasy novel by Jules Verne and is one of the earliest entries in that genre. It tells the story of a French people and two well-to-do members of a post-American Civil War gun club who build an enormous sky-facing columbiad and launch themselves in a projectile/spaceship from it to...
, written in 1865, although landing was made as the sequel, Around the Moon
Around the Moon

Around the Moon , Jules Verne's sequel to From the Earth to the Moon, is a science fiction novel continuing the trip to the moon which left the reader in suspense after the previous novel....
, reveals.

e the Soviet Union
Soviet Union

The Union of Soviet Socialist Republics was a Constitution of the Soviet Union socialist state that existed in Eurasia from 1922 to 1991.The name is a translation of the , romanization of Russian Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated ????, SSSR....
 first succeeded in implementing the concept in 1966, this term referred to 18 spacecraft landings on the Moon through 1976.






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Apollo 11 First Step
A moon landing is the arrival of an intact manned or unmanned spacecraft
Spacecraft

A spacecraft is a Craft or machine designed for spaceflight. On a sub-orbital spaceflight, a spacecraft enters outer space then returns to the Earth....
 on the surface of a planet
Planet

A planet , as 2006 definition of planet by the International Astronomical Union , is a celestial body orbiting a star or Stellar evolution#Stellar remnants that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared the neighbourhood of planetesimals....
's natural satellite
Natural satellite

A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called the primary. Technically, the term natural satellite could refer to a planet orbiting a star, or a dwarf galaxy orbiting a major galaxy, but it is normally synonymous with moon and used to identify non-artificial satellites...
. The concept has been a goal of humankind since it was first appreciated that the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
 is Earth
Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
's closest large celestial body. One of the clearest early examples of the concept in fiction was Jules Verne
Jules Verne

Jules Gabriel Verne was a France author who helped pioneer the science fiction genre. He is best known for his novels Journey to the Center of the Earth , From the Earth to the Moon , Twenty Thousand Leagues Under the Sea , and Around the World in Eighty Days ....
's novel From the Earth to the Moon
From the Earth to the Moon

From the Earth to the Moon is a humorous science fantasy novel by Jules Verne and is one of the earliest entries in that genre. It tells the story of a French people and two well-to-do members of a post-American Civil War gun club who build an enormous sky-facing columbiad and launch themselves in a projectile/spaceship from it to...
, written in 1865, although landing was made as the sequel, Around the Moon
Around the Moon

Around the Moon , Jules Verne's sequel to From the Earth to the Moon, is a science fiction novel continuing the trip to the moon which left the reader in suspense after the previous novel....
, reveals.

Unmanned landings

Since the Soviet Union
Soviet Union

The Union of Soviet Socialist Republics was a Constitution of the Soviet Union socialist state that existed in Eurasia from 1922 to 1991.The name is a translation of the , romanization of Russian Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated ????, SSSR....
 first succeeded in implementing the concept in 1966, this term referred to 18 spacecraft landings on the Moon through 1976. Nine of these missions returned to Earth bearing samples of moon rocks. United States and India are the other countries to make unmanned moon landings.

The Soviet Union later achieved sample returns
Sample return mission

A sample return mission is a spacecraft mission with the goal of returning tangible samples from an Wiktionary:extraterrestrial#Adjective location to Earth for analysis....
 via the unmanned Luna 16
Luna 16

Luna 16 was an unmanned space mission of the Luna program, also called Lunnik 16 .Luna program 16 was the first robotic probe to land on the Moon and return a sample to Earth....
, Luna 20
Luna 20

Luna 20 was an unmanned space mission of the Luna program, also called Lunik 20.Luna 20 was placed in an intermediate Earth parking orbit and from this orbit was sent towards the Moon....
 and Luna 24
Luna 24

Luna 24 was an unmanned space mission of the Luna program, also called Lunik 24. The last of the Luna series of spacecraft, the mission of the Luna 24 probe was the third Soviet mission to retrieve Lunar soil samples ....
 moon landings. Since this was during the time of the Cold War
Cold War

The Cold War was the continuing state of conflict, tension and competition that existed between a number of world powers, including the United States, the Soviet Union, People's Republic of China, France, United Kingdom and those countries' respective allies from the mid-1940s to the early 1990s....
, the contest to be the first on the Moon was one of the most visible facets of the Space Race
Space Race

File:Space race1.jpgThe Space Race was a competition of space exploration between the Soviet Union and the United States, which lasted roughly from 1957 to 1975....
.

Progress in space exploration
Space exploration

Space exploration is the use of astronomy and space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....
 has since broadened the phrase to include other moons in the solar system
Solar System

The Solar System consists of the Sun and those Astronomical object bound to it by gravity: the eight planets and five dwarf planets, their 173 known Natural satellite, and billions of Small Solar System body....
 as well. The Huygens probe
Huygens probe

The Huygens probe, supplied by the European Space Agency and named after the Dutch 17th century astronomer Christiaan Huygens, was an atmospheric entry probe carried to Saturn 's moon Titan as part of the Cassini-Huygens mission....
 of the Cassini
Cassini-Huygens

Cassini?Huygens is a joint NASA/European Space Agency robotic spacecraft mission currently studying the planet Saturn and Saturn's natural satellites....
 mission to Saturn
Saturn

Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn, along with Jupiter, Uranus and Neptune, is classified as a gas giant....
 performed a successful unmanned moon landing on Titan
Titan (moon)

Titan or Saturn VI is the largest natural satellite of Saturn, the only moon known to have a dense celestial body atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
 in 2005. Similarly, the Soviet probe Phobos 2 came within of performing an unmanned moon landing on Mars' moon Phobos
Phobos (moon)

'Phobos' is the larger and closer of Mars ' two small natural satellites, the other being Deimos . It is named after the Greek mythology Phobos , a son of Ares ....
 in 1989 before radio
Radio

Radio is the transmission of signals, by modulation of electromagnetic radiation with frequency below those of visible light.Electromagnetic radiation radio propagation by means of oscillating electromagnetic fields that pass through the air and the vacuum of space....
 contact with that lander was suddenly lost. A similar Russian sample return mission called Phobos-Grunt
Phobos-Grunt

Phobos-Grunt is a planned Russian sample return mission to Phobos , one of the natural satellite of Mars . A China Mars orbiter will be sent together with the mission....
 ("grunt" means "soil" in Russian) is scheduled for launch in October 2009. There is widespread interest in performing a future moon landing on Jupiter's moon Europa
Europa (moon)

'Europa' is the Moons_of_Jupiter#Table Natural satellite of the planet Jupiter. Europa was discovered in 1610 by Galileo Galilei , and named after a mythical Phoenician noblewoman, Europa , who was courted by Zeus and became the queen of Crete....
 to drill down and explore the possible liquid water ocean beneath its icy surface.

Manned Landings

The United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 space agency NASA
NASA

The National Aeronautics and Space Administration is an agency of the Federal government of the United States, responsible for the nation's public list of space agencies....
 achieved the first manned landing on Earth's Moon as part of the Apollo 11
Apollo 11

The Apollo 11 mission was the first manned mission to land on the Moon. It was the fifth human spaceflight of Apollo program and the third human voyage to the Moon....
 mission commanded by Neil Armstrong
Neil Armstrong

Neil Alden Armstrong is a former American astronaut, test pilot, university professor, and United States Naval Aviator. He is List of Apollo astronauts#People who have walked on the Moon Moon....
. On July 20, 1969, Armstrong landed the lunar module
Apollo Lunar Module

The Apollo Lunar Module was the Lander portion of the Apollo spacecraft built for the United States Apollo program by Grumman to achieve the transit from cislunar orbit to the surface and back....
 Eagle on the surface of the Moon with a companion, while the third astronaut orbited above. Armstrong and Buzz Aldrin
Buzz Aldrin

Buzz Aldrin is an United States aviator and astronaut, who was the Lunar Module Pilot on Apollo 11, the first lunar landing. He was, along with Mission Commander Neil Armstrong, the first person to land on the Moon, and shortly afterward became the second person to set foot on the Moon....
 spent a day on the surface of the Moon before returning to Earth. NASA carried out six manned moon landings between 1969 and 1972.

Scientific background

The primary concern of any moon landing is the high velocity involved that arises from the effects of gravity. In order to go to any moon, a spacecraft must first leave the gravity well
Gravity well

In physics, a gravity well is the gravitational potential field around a massive body . Physical models of gravity wells are sometimes used to illustrate orbital mechanics....
 of the Earth. The only practical way of accomplishing this currently is with a rocket
Rocket

A rocket or rocket vehicle is a missile, aircraft or other vehicle which obtains thrust by the Reaction of the rocket to the ejection of fast moving fluid exhaust from a rocket engine....
. Unlike other airborne vehicles such as balloons
Balloon (aircraft)

A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be propelled through the air in a controlled manner....
 or jets
Jet aircraft

A jet aircraft is an aircraft propelled by jet engines. Jet aircraft fly much faster than propeller-powered aircraft and at higher altitudes -- as high as 10,000 to 15,000 meters ....
, only a rocket can continue to increase its speed
Speed

Speed is the rate of Motion , or equivalently the rate of change of distance.Speed is a Scalar quantity with dimensions length/time; the equivalent Vector quantity to speed is velocity....
 at high altitudes in the vacuum
Vacuum

A vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty," but in reality, no volume of space can ever be perfectly empty....
 outside the Earth's atmosphere
Atmosphere

An atmosphere is a layer of gases that may surround a material body of sufficient mass, by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low....
.

Upon approach of the target moon, the spacecraft must decelerate enough to land safely. The velocity to be shed from the target moon's gravitational attraction is roughly equal to the escape velocity
Escape velocity

In physics, escape velocity is the speed where the kinetic energy of an object is equal to the magnitude of its gravitational potential energy, as calculated by the equation,...
 of the target moon. For Earth's Moon, this figure is 2.4 kilometers per second or around 6,000 miles per hour. This change in velocity (referred to as the delta-v
Delta-v

In astrodynamics, the term delta-v, literally "change in velocity" , has a specific meaning: it is a scalar which takes units of speed that measures the amount of "effort" needed to carry out an orbital maneuver, i.e., to change from one trajectory to another....
) is usually provided by a landing rocket, which must be carried into space by the original launch vehicle
Launch vehicle

In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....
 as part of the overall spacecraft. An exception is a moon landing on Titan such as that carried out by the Huygens probe. As the only moon with an atmosphere, landings on Titan may be accomplished by using atmospheric entry
Atmospheric reentry

Atmospheric reentry refers to the movement of human-made or natural objects as they enter the atmosphere of a planet from outer space, in the case of Earth from an altitude above the "edge of space." This article primarily addresses the process of controlled reentry of vehicles which are intended to reach the planetary surface intact, but th...
 techniques that are generally lighter in weight than a rocket with equivalent capability.

Whatever method is used to slow a spacecraft as it nears a moon, the key requirement
Requirement

In engineering, a requirement is a singular documented need of what a particular product or service should be or do. It is most commonly used in a formal sense in systems engineering or software engineering....
 for a "true" moon landing is to be traveling at a survivable
Survivability

Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts....
 speed upon reaching the moon's surface that allows continued operation after touchdown. Such landings may be characterized as "soft" if a human could survive them, and "hard" if only a ruggedized machine would do so. Initial American attempts at performing the first hard moon landing in 1962 failed; the Soviets succeeded in making the first successful hard landing on the Moon in 1966. Generally a hard landing is categorized as one occurring at 100 miles per hour or slower.

Above these speeds, the space mission ends not in a landing but a so-called crash impact where the vehicle and its instruments do not survive touchdown, which without braking rockets generally occurs at speeds of 3000-5000 miles per hour. Such impacts can occur because of malfunctions in a spacecraft, or they can be deliberately arranged for vehicles that do not have an on board landing rocket such as the 2008 Indian MIP. There have been many such moon crashes
List of artificial objects on the Moon

The following table is a partial list of artificial objects on the surface of the Moon. The list does not include smaller objects such as the retroreflectors and Apollo Lunar Surface Experiment Package....
. For example, during the Apollo program the S-IVB
S-IVB

The S-IVB was built by the Douglas Aircraft Company and served as the third stage on the Saturn V and second stage on the Saturn IB. It had one J-2 engine....
 third stage of the Saturn V
Saturn V

The Saturn V was a multistage rocket liquid-fuel expendable launch system rocket used by NASA's Apollo program and Skylab programs from 1967 until 1973....
 moon rocket as well as the spent ascent stage of the lunar module were deliberately crashed on the moon several times to provide impacts registering as a moonquake
Moonquake

A moonquake is the lunar equivalent of an earthquake, i.e., a quake on the Moon. Moonquakes are much less common and weaker than earthquakes. Information about moonquakes comes from seismometers placed on the Moon by Apollo program astronauts from 1969 through 1972....
 on seismometers that had been left on the lunar surface. Such crashes were instrumental in mapping the internal structure of the Moon
Internal structure of the Moon

The Moon is a Planetary differentiation body, being composed of a Geochemistry distinct Crust , Mantle , and Planetary core. This structure is believed to have resulted from the Fractional crystallization of a Lunar magma ocean shortly after its formation about 4.5 billion years ago....
.

If a return to Earth is desired after a moon landing is accomplished, the escape velocities of the moon and Earth must again be overcome for the spacecraft to come to rest on the surface of the Earth. Rockets must be used to leave the moon and return to space. Upon reaching Earth, atmospheric entry techniques are used to absorb the kinetic energy
Kinetic energy

The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the mechanical work needed to accelerate a body of a given mass from rest to its current velocity....
 of a returning spacecraft and reduce its speed for safe landing. These functions greatly complicate a moon landing mission and lead to many additional operational considerations. Any moon departure rocket must first be carried to the moon's surface by a moon landing rocket, increasing the latter's required size. The moon departure rocket, larger moon landing rocket and any Earth atmosphere entry equipment such as heat shields and parachute
Parachute

A parachute is a device used to slow the motion of an object through an atmosphere by creating Drag .Parachutes are made out of cloth, most commonly nylon....
s must in turn be lifted by the original launch vehicle, greatly increasing its size by a significant and almost prohibitive degree. This necessitates optimizing the sizing of stages
Multistage rocket

A multistage rocket is a rocket that usestwo or more stages, each of which contains its own Rocket engine and Rocket propellant. A tandem or serial stage is mounted on top of another stage; a parallel stage is attached alongside another stage....
 in the launch vehicle as well as consideration of using space rendezvous
Space rendezvous

A space rendezvous between two spacecraft, often between a spacecraft and a space station, is an orbital maneuver where the two arrive at the same orbit, make their orbital velocity the same, and bring them together ; it may or may not include docking....
 between multiple spacecraft and reaching intermediate orbits prior to landing; in particular, lunar orbit rendezvous
Lunar orbit rendezvous

Lunar orbit rendezvous was the method used by the Project Apollo for human spaceflight to the Moon. In an LOR mission a main spacecraft and a smaller Lunar Module travel together into lunar orbit ....
. Thus systems engineering
Systems engineering

Systems engineering is an interdisciplinary field of engineering that focuses on how complex engineering projects should be designed and managed....
 and logistics become major factors in the design of any moon landing mission.

Political background

The intense and expensive effort devoted in the 1960s to achieving first an unmanned and then ultimately a manned moon landing can only be understood in the political context of its historical era. World War II
World War II

World War II, or the Second World War , was a global military conflict which involved a Participants in World War II, including all of the great powers, organised into two opposing military alliances: the Allies of World War II and the Axis powers....
 with its 60 million dead, half Soviet, was fresh in the memory of all adults. In the 1940s, the war had introduced many new and deadly innovations including blitzkrieg
Blitzkrieg

Blitzkrieg is "a headline word applied retrospectively to describe a military doctrine of an all-mechanized force concentration its attack on a small section of the enemy front then, once the latter is pierced, proceeding without regard to its flank." As British military historian Sir John Keegan has noted, it was an idea which owed its cre...
-style surprise attacks used in the invasion of Poland and in the attack on Pearl Harbor
Attack on Pearl Harbor

The attack on Pearl Harbor was a surprise military strike conducted by the Empire of Japan Imperial Japanese Navy against the United States' naval base at Pearl Harbor, Hawaii, on the morning of Sunday, December 7, 1941, later resulting in the United States becoming militarily involved in World War II....
; the V-2 rocket
V-2 rocket

The V-2 rocket was the first ballistic missile and first man-made object to achieve sub-orbital spaceflight, the progenitor of all modern rockets....
, a ballistic missile
Ballistic missile

A ballistic missile is a missile that follows a sub-orbital ballistics flightpath with the objective of delivering a warhead to a predetermined target....
 which killed thousands in attacks on London
London

London is the capital of both England and the United Kingdom, and the most populous municipality in the European Union. An important settlement for two millennia, History of London goes back to its founding by the Roman Empire....
; and the atom bomb, which killed tens of thousands in the atomic bombings of Hiroshima and Nagasaki
Atomic bombings of Hiroshima and Nagasaki

The atomic bombings of Hiroshima and Nagasaki were nuclear warfares near the end of World War II against the Empire of Japan by the United States at the executive order of President of the United States Harry S....
. In the 1950s, tensions mounted between the two ideologically opposed superpowers of the United States
United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
 and the Soviet Union
Soviet Union

The Union of Soviet Socialist Republics was a Constitution of the Soviet Union socialist state that existed in Eurasia from 1922 to 1991.The name is a translation of the , romanization of Russian Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated ????, SSSR....
  that had emerged as victors in the conflict, particularly after the development by both countries of the hydrogen bomb.

On October 4, 1957, the Soviet Union launched
Rocket launch

A rocket launch is the first phase of the flight of a rocket. For orbital spaceflights, or for launches into interplanetary space, which is usually a fixed location on the ground but may also be on a floating platform such as the San Marco platform, or the Sea Launch launch vessel....
 Sputnik 1
Sputnik 1

Sputnik 1 was the world's first Earth-orbiting artificial satellite. It was launched into a low altitude elliptical orbit by the Soviet Union on October 4, 1957, and was the first in a series of satellites collectively known as the Sputnik program....
 as the first artificial satellite to orbit the Earth and so initiated the Space Age
Space Age

The Space Age is a contemporary period encompassing the activities related to the Space Race, space exploration, space technology, and the cultural developments influenced by these events....
. This unexpected event was a source of pride to the Soviets and shock
Culture shock

Culture shock refers to the anxiety and feelings felt when people have to operate within a different and unknown cultural or social environment, such as a foreign country....
 to the Americans. This dramatic and successful demonstration of the new R-7 Semyorka
R-7 Semyorka

The R-7 Semyorka was the world's first true intercontinental ballistic missile and was deployed by the Soviet Union during the Cold War from 1959 to 1968....
 rocket on only its third test flight meant that the Soviets could use ballistic missiles carrying hydrogen bombs in a surprise attack against any target on Earth, a frightening new capability the Americans did not have. Further, the steady beeping of the radio beacon aboard Sputnik 1 as it passed overhead every 96 minutes was widely viewed on both sides as effective propaganda
Propaganda

Propaganda is the dissemination of information aimed at influencing the opinions or behaviors of large numbers of people. As opposed to Objectivity providing information, propaganda in its most basic sense presents information in order to influence its audience....
 to Third World
Third World

Third World is a categorical label used to describe states that are considered to be developed in terms of their economy or level of industrialization, globalization, standard of living, health, education or other criteria for 'advancements'....
 countries demonstrating the technological superiority of the Soviet political system
Political system

A political system is a system of politics and government. It is usually compared to the law system, economic system, cultural system, and other social systems....
 compared to the American one. This perception was reinforced by a string of subsequent rapid-fire Soviet space achievements. In 1959, the R-7 rocket was used to launch the first escape from Earth's gravity into a solar orbit, the first crash impact onto the surface of the Moon and the first photography
Photography

Photography is the process, activity and art of creating still or moving by recording radiation on a sensitive medium, such as a photographic film, or an ....
 of the never-before-seen far side of the Moon
Far side of the Moon

The far side of the Moon is the Moon hemisphere that is permanently turned away from the Earth. The far hemisphere was first photographed by the Soviet Luna 3 probe in 1959, and was first directly observed by human eyes when the Apollo 8 mission orbited the Moon in 1968....
. These were the Luna 1
Luna 1

Luna programme 1 , also known as Mechta was the first spacecraft to reach the vicinity of the Moon and the first of the Luna programme of Soviet automatic interplanetary stations successfully launched in the direction of the Moon....
, Luna 2
Luna 2

Luna 2 was the second of the Soviet Union Luna programme spacecraft launched in the direction of the Moon. It was the first spacecraft to reach the surface of the Moon....
 and Luna 3
Luna 3

The Soviet space probe Luna 3 was the third spacecraft sent successfully to the Moon, and it was an early feat in the human exploration of outer space....
 spacecraft, respectively.

The American response to these Soviet achievements was to greatly accelerate previously languishing space and missile projects. Military efforts were initiated to develop and produce mass quantities of intercontinental ballistic missiles (ICBMs) that would bridge the so-called missile gap
Missile gap

The missile gap was the term used in the United States for the perceived disparity between the number and power of the weapons in the U.S.S.R. and United States ballistic missile arsenals during the Cold War....
 and enable a policy of deterrence
Deterrence theory

Deterrence theory is a military strategy developed during the Cold War. It is especially relevant with regard to the use of nuclear weapons, and figures prominently in current United States foreign policy regarding the development of nuclear technology in North Korea and Iran....
 to nuclear war
Nuclear warfare

Nuclear warfare, or atomic warfare refers to the strategy for fighting or deterring military conflicts and terrorism when nuclear weapons are present....
 with the Soviets known as Mutually Assured Destruction or MAD. These newly-developed missile
Missile

A guided missile is a self-propelled projectile used as a weapon. Missiles are typically propelled by rockets or jet engines. Missiles generally have one or more explosive warheads, although other weapon types may also be used....
s were made available to civilians of the newly formed NASA
NASA

The National Aeronautics and Space Administration is an agency of the Federal government of the United States, responsible for the nation's public list of space agencies....
 space agency for various projects which would demonstrate the payload, guidance accuracy and reliabilities of American ICBMs to the Soviets. While NASA stressed peaceful and scientific uses for these rockets, their use in various lunar exploration efforts also had secondary goal of realistic, goal-oriented testing of the missiles themselves and development of associated infrastructure just as the Soviets were doing with their R-7. The tight schedules and lofty goals selected by NASA for lunar exploration also had an undeniable element of generating counter-propaganda to show to other countries that American technological prowess was the equal and even superior to that of the Soviets.

U.S. unmanned hard landings (1958-1965)

In contrast to Soviet lunar exploration triumphs in 1959, success eluded initial American efforts to reach the Moon with the Pioneer
Pioneer program

The Pioneer program is a series of United States unmanned space missions that was designed for planetary exploration. There were a number of such missions in the program, but the most notable were Pioneer 10 and Pioneer 11, which explored the outer planets and left the solar system....
 and Ranger
Ranger program

The Ranger program was a series of unmanned space missions by the United States in the 1960s whose objective was to obtain the first close-up images of the surface of the Moon....
 programs. Fifteen consecutive U.S. unmanned lunar missions over a six year period from 1958 to 1964 all failed their primary photographic missions; however Rangers 4 and 6 successfully repeated the Soviet lunar impacts as part of their secondary missions. Failures included three American attempts in 1962 to hard land small seismometer packages released by the main Ranger spacecraft. These surface packages were to use retrorockets to survive landing, unlike the parent vehicle, which was designed to deliberately crash onto the surface. The final three Ranger probes performed successful high altitude lunar reconnaissance
Reconnaissance

Reconnaissance is a military and medical term denoting exploration conducted to gain information. Militarily, its shorthand Australian, Canadian, and British form is recce , its American usage form is recon ....
 photography missions during intentional crash impacts at around 6,000 miles per hour as planned.

Three different designs of Pioneer lunar probes were flown on three different modified ICBMs. Those flown on the Thor
PGM-17 Thor

Thor was the first operational ballistic missile in the arsenal of the United States, operated by the US Air Force. Thor was in height and in diameter....
 booster modified with an Able upper stage carried an infrared
Infrared

Infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light , but shorter than that of terahertz radiation and microwaves ....
 image scanning television
Television

Television is a widely used telecommunication mass-media for transmitting and receiving moving , either monochrome or color, usually accompanied by sound....
 system with a resolution
Image resolution

Image resolution describes the detail an holds. The term applies equally to digital images, film images, and other types of images. Higher resolution means more image detail....
 of 1 milliradian to study the Moon's surface, an ionization chamber
Ionization chamber

An ionization chamber is a device used for two major purposes: detecting particles in air , and for detection or measurement of ionizing radiation....
 to measure radiation
Radiation

In physics, radiation describes any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body....
 in space, a diaphragm/microphone assembly to detect micrometeorites, a magnetometer
Magnetometer

A magnetometer is a scientific instrument used to measure the strength and/or direction of the magnetic field in the vicinity of the instrument....
, and temperature-variable resistors to monitor spacecraft internal thermal conditions. The first, a mission managed by the United States Air Force
United States Air Force

The United States Air Force is the aerial warfare branch of the Military of the United States and one of the uniformed services of the United States....
, exploded during launch; all subsequent Pioneer lunar flights had NASA as the lead management organization. The next two returned to Earth and burned up upon reentry into the atmosphere after achieved maximum altitudes of around 70,000 and , far short of the roughly required to reach the vicinity of the Moon.

NASA then collaborated with the United States Army
United States Army

The United States Army is the branch of the United States Armed Forces responsible for Army operations. It is the largest and oldest established branch of the U.S....
's Ballistic Missile Agency
Army Ballistic Missile Agency

The Army Ballistic Missile Agency was the agency formed to develop the United States Army first intermediate range ballistic missile. It was established at Redstone Arsenal on February 1, 1956 and commanded by Major General John Bruce Medaris with Doctor Wernher von Braun....
 to fly two extremely small cone-shaped probes on the Juno
Juno (spacecraft)

Juno is a NASA New Frontiers program class mission led by Dr. Scott Bolton to the planet Jupiter. It was originally proposed at a cost of approximately USD $700 million for a June 2009 launch....
 ICBM, carrying only photocells which would be triggered by the light of the Moon and a lunar radiation environment experiment using a Geiger-Müller tube
Geiger-Müller tube

A Geiger-M?ller tube is the sensing element of a Geiger counter instrument that can detect a single particle of ionizing radiation, and typically produce an audible click for each....
 detector. The first of these reached an altitude of only around , serendipitously gathering data that established the presence of the Van Allen radiation belts before reentering Earth's atmosphere. The second passed by the moon at a distance of over , twice as far away as planned and too far away to trigger either of the on board scientific instruments, yet still becoming the first American spacecraft to reach a solar orbit.

The final Pioneer lunar probe design consisted of four "paddlewheel" solar panels
Photovoltaic module

In the field of photovoltaics, a photovoltaic module or photovoltaic panel is a packaged interconnected assembly of photovoltaic cells, also known as solar cells....
 extending from a one-meter diameter spherical spin-stabilized spacecraft body that was equipped to take images of the lunar surface with a television-like system, estimate the Moon's mass and topography of the poles
Peak of Eternal Light

Peak of Eternal Light describes a point on a body within the Solar System which is eternally bathed in sunlight. This is due to both the bodies' rotation and the point's altitude....
, record the distribution and velocity of micrometeorites, study radiation, measure magnetic fields, detect low frequency electromagnetic waves in space and use a sophisticated integrated propulsion
Spacecraft propulsion

Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research....
 system for maneuvering and orbit insertion as well. None of the four spacecraft built in this series of probes survived launch on its Atlas
Atlas (missile)

The SM-65 Atlas was a missile built by the Convair Division of General Dynamics. Originally designed as an ICBM in the late 1950s, Atlas was the foundation for a family of successful space launch vehicles now built by United Launch Alliance....
 ICBM outfitted with an Able upper stage.

Following the unsuccessful Atlas-Able Pioneer probes, NASA's Jet Propulsion Laboratory
Jet Propulsion Laboratory

Jet Propulsion Laboratory is a List of federally funded research and development centers and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, California, United States....
 embarked upon an unmanned spacecraft development program whose modular design could be used to support both lunar and interplanetary exploration missions. The interplanetary versions were known as Mariners
Mariner program

The Mariner program was a program conducted by the United States space agency NASA that launched a series of Robotic spacecraft Space probe designed to investigate Mars, Venus and Mercury ....
; lunar versions were Rangers
Ranger program

The Ranger program was a series of unmanned space missions by the United States in the 1960s whose objective was to obtain the first close-up images of the surface of the Moon....
. JPL envisioned three versions of the Ranger lunar probes: Block I prototypes, which would carry various radiation detectors in test flights to a very high Earth orbit that came nowhere near the Moon; Block II, which would try to accomplish the first Moon landing by hard landing a seismometer package; and Block III, which would crash onto the lunar surface without any braking rockets while taking very high resolution wide-area photographs of the Moon during their descent.

The Ranger 1 and 2 Block I missions were virtually identical. Spacecraft experiments included a Lyman-alpha telescope, a rubidium-vapor magnetometer
Magnetometer

A magnetometer is a scientific instrument used to measure the strength and/or direction of the magnetic field in the vicinity of the instrument....
, electrostatic analyzers, medium-energy-range particle detector
Particle detector

In experimental and applied particle physics and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify high-energy Elementary particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator....
s, two triple coincidence telescopes, a cosmic-ray integrating ionization chamber
Ionization chamber

An ionization chamber is a device used for two major purposes: detecting particles in air , and for detection or measurement of ionizing radiation....
, cosmic dust
Cosmic dust

Cosmic dust is a type of dust composed of particles in space which are a few molecules to 0.1 mm in size. Cosmic dust can be further distinguished by its astronomical location; for example: intergalactic dust, interstellar dust , interplanetary dust and circumplanetary dust ....
 detectors, and scintillation counter
Scintillation counter

A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic , or organic liquid that fluoresces when struck by ionizing radiation....
s. The goal was to place these Block I spacecraft in a very high Earth orbit with an apogee of . From that vantage point, scientists could make direct measurements of the magnetosphere
Magnetosphere

A magnetosphere is a highly magnetized region around and possessed by an astronomical object. Earth is surrounded by a magnetosphere, as are the magnetized planets Mercury , Jupiter, Saturn, Uranus, and Neptune....
 over a period of many months while engineers perfected new methods to routinely track and communicate with spacecraft over such large distances. Such practice was deemed vital to be assured of capturing high-bandwidth television transmissions from the Moon during a one-shot fifteen minute time window in subsequent Block II and Block III lunar descents. Both Block I missions suffered failures of the new Agena upper stage and never left low earth parking orbit
Parking orbit

A parking orbit is a temporary orbit used during the launch of a satellite or other space probe. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory....
 after launch; both burned up upon reentry after only a few days.

The first attempts to perform a Moon landing took place in 1962 during the Rangers 3, 4 and 5 missions flown by the United States. All three Block II missions carried a 94 pound, two-foot diameter landing sphere (made of balsa
Balsa

Balsa is a large, fast-growing tree that can grow up to 30m ]] tall, native to tropical South America north to southern Mexico. It is evergreen, or dry-season deciduous if the dry season is long, with large weakly palmately lobed leaves....
 wood) designed to withstand a 150 mile per hour impact. This lander (code-named Tonto) was designed to provide impact cushioning using an exterior blanket of crushable balsa wood and an interior filled with incompressible liquid freon
Freon

Freon is DuPont's trade name for its odorless, colorless, nonflammable, and noncorrosive chlorofluorocarbon and hydrochlorofluorocarbon refrigerants, which are used in air conditioning, refrigeration and some automatic fire-fighting systems....
. A 56 pound, one-foot diameter metal payload sphere floated and was free to rotate in a liquid freon reservoir contained in the landing sphere. This payload sphere contained six silver-cadmium
Cadmium

Cadmium is a chemical element with the symbol Cd and atomic number 48. A relatively abundant , soft, bluish-white, transition metal, cadmium is known to cause cancer and occurs with zinc ores....
 batteries to power a fifty milliwatt radio transmitter, a temperature sensitive voltage controlled oscillator to measure lunar surface temperatures, and a seismometer that was designed with sensitivity high enough to detect the impact of a five pound meteorite on the opposite side of the Moon. Weight was distributed in the payload sphere so it would rotate in its liquid blanket to place the seismometer into an upright and operational position no matter what the final resting orientation of the external landing sphere. After landing plugs were to be opened allowing the freon to evaporate and the payload sphere to settle into upright contact with the landing sphere. Four pounds of water were also included to provide thermal control for the lander, absorbing heat and boiling off as low-pressure steam during the hot lunar daytime and retaining sufficient heat to allow the lander electronics to avoid freezing temperatures during the cold lunar nighttime. The batteries and water supply were sized to allow up to three months of operation for the payload sphere. Various mission constraints limited the landing site to Oceanus Procellarum on the lunar equator, which the lander ideally would reach 66 hours after launch.

No cameras were carried by the Ranger landers, and no pictures were to be captured from the lunar surface during the mission. Instead, the ten-foot-high, 730 pound Ranger Block II mother ship carried a 200 scan line television camera which was to capture images from down to during the free-fall descent to the lunar surface. The 13 pound camera was designed to transmit a picture every 10 seconds. Other instruments gathering data before the mother ship crashed onto the Moon at 6,500 miles per hour were a gamma ray spectrometer to measure overall lunar chemical composition and a radar altimeter. At eight seconds before impact and above the lunar surface, the radar altimeter was to give a signal ejecting the landing capsule and its 236 pound solid-fueled braking rocket overboard from the Block II mother ship. The braking rocket was to slow the landing sphere to a dead stop at above the surface and separate, allowing the landing sphere to free fall once more and hit the surface at a survivable speed of 100 miles per hour.

On Ranger 3, failure of the Atlas guidance system and a software error aboard the Agena upper stage combined to put the spacecraft on a course that would miss the Moon. Attempts to salvage lunar photography during a flyby of the Moon were thwarted by in-flight failure of the onboard flight computer. This was probably because of prior heat sterilization
Sterilization (microbiology)

Sterilization refers to any process that effectively kills or eliminates transmissible agents from a surface, equipment, article of food or medication, or biological culture medium....
 of the spacecraft by keeping it above the boiling
Boiling

Boiling, a type of phase transition, is the rapid vaporization of a liquid, which typically occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environmental pressure....
 point of water for 24 hours on the ground, to protect the Moon from being contaminated by Earth organisms. Heat sterilization was also blamed for subsequent in-flight failures of the spacecraft computer on Ranger 4 and the power subsystem on Ranger 5. Only Ranger 4 reached the Moon in an uncontrolled crash impact on the far side of the Moon.

Ranger7 Pia02975
Heat sterilization was discontinued for the final four Block III Ranger probes. These replaced the Block II landing capsule and its retrorocket with a heavier, more capable television system to support landing site selection for upcoming Apollo manned moon landing missions. Six cameras weighing a total of 350 pounds were designed to take thousands of high-altitude photographs in the final twenty minute period before crashing on the lunar surface. Camera resolution was 1,132 scan lines, far higher than the 525 lines found in a typical American 1964 home television. The final pictures taken were expected to have a resolution of around two feet. While Ranger 6 suffered a failure of this camera system and returned no photographs despite an otherwise successful flight, the subsequent Ranger 7 mission to Mare Cognitum was a complete success. Breaking the six year string of failure in American attempts to photograph the moon at close range, the Ranger 7 mission was viewed as a national turning point and instrumental in allowing the key 1965 NASA budget appropriation to pass through the United States Congress
United States Congress

The United States Congress is the Bicameralism legislature of the Federal government of the United States of the United States of America, consisting of two houses, the United States Senate and the United States House of Representatives....
 intact without a reduction in funds for the Apollo manned moon landing program. Subsequent successes with Ranger 8 and Ranger 9 further buoyed American hopes.

U.S.S.R. unmanned hard landings (1958-1966)

While American lunar exploration missions were undertaken in full view of public scrutiny, Soviet moonshots of the 1960s and 1970s were conducted under a policy of extreme governmental secrecy. Only with the coming of glasnost
Glasnost

was the policy of maximal publicity, openness, and transparency in the activities of all government institutions in the Soviet Union, together with freedom of information, introduced by Mikhail Gorbachev in the second half of 1980s....
 in the late 1980s and the fall of the Soviet Union in 1991 did historical records come to light allowing a true accounting of Soviet lunar efforts. Unlike the American tradition of assigning a particular mission name in advance of launch, the Soviets assigned a public "Luna
Luna programme

The Luna programme , occasionally called Lunik or Lunnik, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976....
" mission number only if a launch resulted in a spacecraft going beyond Earth orbit. If the attempt failed in Earth orbit before departing for the Moon, it was frequently (but not always) given a "Sputnik" or "Cosmos
Cosmos (satellite)

Cosmos is the name of a series of satellites which were launched by the Soviet Union and are being launched now by Russia. The first of them was launched on March 16 1962....
" earth-orbit mission number to hide its failure in reaching the Moon. Launch explosions were not acknowledged at all. This policy had the effect of hiding Soviet moonshot failures from public view, making their successes seem even more impressive.

The Luna 9
Luna 9

Luna 9 , also known as Lunik 9 , was an unmanned space mission of the Soviet Union's Luna program. On February 3, 1966 the Luna 9 spacecraft was the first spacecraft to achieve a Moon Soft landing and to transmit photographic data to Earth....
 spacecraft, launched by the Soviet Union
Soviet Union

The Union of Soviet Socialist Republics was a Constitution of the Soviet Union socialist state that existed in Eurasia from 1922 to 1991.The name is a translation of the , romanization of Russian Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated ????, SSSR....
, performed the first successful Moon landing on February 3 1966 using the "hard landing" technique. Airbags protected its 200 pound ejectable capsule which survived an impact speed of over 30 miles per hour—the speed of many automobile accidents causing fatalities on Earth. Luna 13
Luna 13

Luna 13 was an unmanned space mission of the Luna program, also called Lunik 13.The Luna 13 spacecraft was launched toward the Moon from an earth-orbiting platform and accomplished a soft landing on December 24, 1966, in the region of Oceanus Procellarum....
 duplicated this feat with a similar moon landing on December 24, 1966. Both returned panoramic photographs that were the first views from the lunar surface.

American unmanned soft landings (1966-1968)

The American robot
Robot

A robot is a virtual or mechanical artificial agent. In practice, it is usually an Electromechanics which, by its appearance or movements, conveys a sense that it has Intention or Agency of its own....
ic Surveyor program
Surveyor program

The Surveyor Program was a NASA program that, from 1966 through 1968, sent seven robotic spacecraft to the surface of the Moon. Its primary goal was to demonstrate the feasibility of soft landings on the Moon....
 was part of an effort to locate a safe site on the Moon for a human landing and test under actual lunar conditions the radar
Radar

Radar is a system that uses electromagnetic radiation waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain....
 and landing systems required to make a true controlled touchdown. Five of Surveyor's seven missions made successful unmanned moon landings.

Transition From Direct Ascent Landings To Lunar Orbit Operations (1966)


Within four months of each other in early 1966 the Soviet Union and the United States had accomplished successful moon landings with unmanned spacecraft. To the general public both countries had demonstrated roughly equal technical capabilities by returning photographic images from the surface of the Moon. These pictures provided a key affirmative answer to the crucial question of whether or not lunar soil would support upcoming manned landers with their much greater weight.

However, the Luna 9 hard landing of a ruggedized sphere using airbags at a -per-hour ballistic impact speed had much more in common with the failed 1962 Ranger landing attempts and their planned -per-hour impacts than with the Surveyor 1 soft landing on three footpads using its radar-controlled, adjustable-thrust retrorocket. While Luna 9 and Surveyor 1 were both major national accomplishments, only Surveyor 1 had reached its landing site employing key technologies that would be needed for a crewed flight. Thus as of mid-1966, the United States had begun to pull ahead of the Soviet Union in the so-called Space Race to land a man on the Moon.

Advances in other areas were necessary before manned spacecraft could follow unmanned ones to the surface of the Moon. Of particular importance was developing the expertise to perform flight operations in lunar orbit. Ranger, Surveyor and initial Luna moon landing attempts all utilized flight paths from Earth that traveled directly to the lunar surface without first placing the spacecraft in a lunar orbit. Such direct ascent
Direct ascent

Direct ascent was a proposed method for a mission to the Moon. In the United States, direct ascent proposed using the enormous Nova rocket or Saturn C-8 to loft a spacecraft directly to the Moon, where it would land tail-first and then launch off the Moon back to Earth....
s use a minimum amount of fuel for unmanned spacecraft on a one-way trip.

In contrast, manned vehicles need additional fuel after a lunar landing to enable a return trip back to Earth for the crew. Leaving this massive amount of required Earth-return fuel in lunar orbit until it is actually used later in the mission is far more efficient than taking such fuel down to the lunar surface in a Moon landing and then hauling it all back into space yet again, working against lunar gravity both ways. Such considerations lead logically to a lunar orbit rendezvous
Lunar orbit rendezvous

Lunar orbit rendezvous was the method used by the Project Apollo for human spaceflight to the Moon. In an LOR mission a main spacecraft and a smaller Lunar Module travel together into lunar orbit ....
 mission profile for a manned Moon landing.

Accordingly, beginning in mid-1966 both the U.S. and U.S.S.R. naturally progressed into missions which featured lunar orbit operations as a necessary prerequisite to a manned Moon landing. The primary goals of these initial unmanned orbiters were extensive photographic mapping of the entire lunar surface for the selection of manned landing sites and, for the Soviets, the checkout of radio communications gear that would be used in future soft landings.

An unexpected major discovery from initial lunar orbiters were vast volumes of dense materials beneath the surface of the moon's maria. Such mascons can send a manned mission dangerously off course in the final minutes of a moon landing when aiming for a relatively small landing zone that is smooth and safe. Mascons were also found over a longer period of time to greatly disturb the orbits of low-altitude satellites around the Moon, making their orbits unstable and forcing an inevitable crash on the lunar surface in the relatively short period of months to a few years. Thus all lunar orbiter satellites eventually become unintentional "lunar landers" at the end of their missions.

Controlling the location of impact for spent lunar orbiters can have scientific value. For example, in 1999 the NASA Lunar Prospector
Lunar Prospector

The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible polar ice deposits, measurements of magnetic...
 orbiter was deliberately targeted to impact a permanently shadowed area of Shoemaker Crater near the lunar south pole. It was hoped that energy from the impact would vaporize suspected shadowed ice deposits in the crater and liberate a water vapor plume that would be detectable from Earth. No such plume was observed. However, a small vial of ashes from the body of pioneer lunar scientist Eugene Shoemaker was delivered by the Lunar Prospector to the crater named in his honor - currently the only human remains on the Moon today.

Soviet lunar orbit satellites (1966-1974)


Luna 10
Luna 10

Luna 10 was an unmanned space mission of the Luna program, also called Lunik 10.The Luna 10 spacecraft was launched towards the Moon from an Earth orbiting platform on March 31, 1966....
 became the first spacecraft to orbit the Moon on 3 April 1966.

U.S. lunar orbit satellites (1966-1967)



Soviet Circumlunar Loop Flights (1967-1970)


It was possible to aim a spacecraft from Earth so that it will loop around the Moon and return to Earth without actually entering lunar orbit, following the so-called free return trajectory
Free return trajectory

A free return trajectory is one of a very small sub-class of trajectories in which the trajectory of a satellite traveling away from a primary body is modified by the presence of a secondary body causing the satellite to return to the primary body....
. Such circumlunar loop missions are simpler than actual lunar orbit missions because rockets for lunar orbit braking and Earth return are not required. However, a manned circumlunar loop trip poses significant challenges above and beyond those found in a manned low-Earth-orbit mission, offering valuable lessons in preparation for a manned moon landing. Foremost among these are mastering the demands of re-entering the Earth's atmosphere upon returning from the Moon. Manned Earth-orbiting vehicles such as the Space Shuttle return to Earth from speeds of around 17,000 miles per hour. Due to the effects of gravity, a vehicle returning from the Moon hits Earth's atmosphere at a much higher speed of around 25,000 miles per hour. The g-loading
G-force

The g-force of an object is its acceleration relative to free-fall. The unit of measure used is informally but commonly known as the "gee" , symbolized as g . An acceleration of 1 g is generally considered as equal to standard gravity , which is defined as precisely metre per second square...
 on astronauts during the resulting deceleration
Acceleration

File:Acceleration.JPGFile:Acceleration components.JPGIn physics, and more specifically kinematics, acceleration is the change in velocity over time....
 can be at the limits of human endurance even during a nominal reentry. Slight variations in the vehicle flight path and reentry angle during a return from the Moon can easily result in fatal levels of deceleration force.

Achieving a manned circumlunar loop flight prior to a manned lunar landing became a primary goal of the Soviets with their Zond spacecraft program. The first three Zonds were unmanned planetary probes; after that, the Zond name was transferred to a completely separate manned program. The initial focus of these later Zonds was extensive testing of required high-speed reentry techniques. This focus was not shared by the Americans, who chose instead to bypass the stepping stone of a manned circumlunar loop mission and never developed a separate spacecraft for this purpose.

Initial manned spaceflights in the early 1960s placed a single person in low Earth orbit during the Soviet Vostok
Vostok programme

The Vostok programme was a Soviet Union human spaceflight project that succeeded in putting a person into Earth orbit for the first time. The programme developed the Vostok spacecraft from the Zenit spy satellite project and adapted the Vostok rocket from an existing ICBM design....
 and American Mercury
Mercury program

Mercury Program might refer to:*the first successful American manned spaceflight program, Project Mercury*an American post-rock band, The Mercury Program...
 programs. A two-flight extension of the Vostok program known as Voskhod
Voskhod programme

The Voskhod programme was a Soviet Union human spaceflight project. Voskhod development was both a follow-on to the Vostok programme, recycling components left over from that programme's cancellation following its first six flights....
 effectively used Vostok capsules with their ejection seats removed to achieve Soviet space firsts of multiple person crews in 1964 and spacewalks in early 1965. These capabilities were later demonstrated by the Americans in ten Gemini low Earth orbit missions throughout 1965 and 1966, using a totally new second-generation spacecraft design that had little in common with the earlier Mercury. These Gemini missions went on to prove critical techniques for orbital rendezvous and docking
Space rendezvous

A space rendezvous between two spacecraft, often between a spacecraft and a space station, is an orbital maneuver where the two arrive at the same orbit, make their orbital velocity the same, and bring them together ; it may or may not include docking....
 that were crucial to a manned lunar landing mission profile.

After the end of the Gemini program, the Soviets Union began flying their second-generation Zond manned spacecraft in 1967 with the ultimate goal of looping a cosmonaut around the moon and returning him immediately to Earth. The Zond spacecraft was launched with the simpler and already operational Proton
Proton rocket

The Proton rocket is a rocket used in an expendable launch system for both commercial and Russian government launches. The first Proton was launched in 1965 and the launch system is still in use as of 2009, which makes it one of the most successful heavy boosters in the history of spaceflight....
 launch rocket, unlike the parallel Soviet manned moon landing effort also underway at the time based on third-generation Soyuz
Soyuz spacecraft

Soyuz ; English: Union) is a series of spacecraft designed for the Soviet space program by the S.P. Korolev Rocket and Space Corporation Energia....
 spacecraft requiring development of the advanced N-1 booster. The Soviets thus believed they could achieve a manned Zond circumlunar flight years before an American manned lunar landing and so score a propaganda victory. However, significant development problems delayed the Zond program and the success of the American Apollo lunar landing program led to the eventual termination of the Zond effort.

Like Zond, Apollo moon flights were generally launched on a free return trajectory that would return them to Earth via a circumlunar loop in the event that a Service Module malfunction failed to place them in lunar orbit as planned. This option was implemented after an explosion aboard the Apollo 13 mission in 1970, which is the only manned circumlunar loop mission flown to date.

Nasa Apollo8 Dec24 Earthrise
Zond 5 was the first spacecraft to carry life from Earth to the vicinity of the Moon and return, initiating the final lap of the Space Race
Space Race

File:Space race1.jpgThe Space Race was a competition of space exploration between the Soviet Union and the United States, which lasted roughly from 1957 to 1975....
 with its payload of turtles, insects, plants and bacteria. Despite the failure suffered in its final moments, the Zond 6 mission was reported by Soviet media as being a success as well. Although hailed worldwide as remarkable achievements, both of these Zond missions actually flew off-nominal reentry trajectories resulting in deceleration forces that would have been fatal to human crewmembers had they been aboard. As a result, the Soviets secretly planned to continue unmanned Zond tests until their reliability to support manned flight had been demonstrated. However, believing from faulty CIA
Central Intelligence Agency

The Central Intelligence Agency is a civilian intelligence agency of the Federal government of the United States. It is the successor of the Office of Strategic Services formed during World War II to coordinate espionage activities between the branches of the US military services....
 intelligence that a Soviet manned lunar flight was imminent in late 1968, NASA fatefully changed the flight plan of Apollo 8 from an Earth-orbit to a riskier lunar orbit mission scheduled for late December 1968.

In early December 1968 the launch window to the Moon opened for the Soviet launch site in Baikonur
Baikonur

Baikonur , formerly known as Leninsk, is a city in Kyzylorda Province of Kazakhstan, rented and administered by Russia. It was constructed to service the Baikonur Cosmodrome and was officially renamed Baikonur by Boris Yeltsin on December 20, 1995....
, giving the USSR their final chance to beat the US to the Moon. Cosmonauts went on alert and asked to fly the Zond spacecraft then in final countdown at Baikonour on the first manned trip to the Moon. Ultimately, however, the Soviet Politburo
Politburo of the Central Committee of the Communist Party of the Soviet Union

The Politburo , known as the Presidium from 1952 to 1966, functioned as the central policymaking and governing body of the Communist Party of the Soviet Union....
 decided the risk of crew death was unacceptable given the combined poor performance to that point of Zond/Proton and so scrubbed the launch of a manned Soviet lunar mission. Their decision proved to be a wise one, since this unnumbered Zond mission was destroyed in another unmanned test when it was finally launched several weeks later.

By this time flights of the third generation American Apollo spacecraft had begun. Far more capable than the Zond, the Apollo spacecraft had the necessary rocket power to slip into and out of lunar orbit and to make course adjustments required for a safe reentry during the return to Earth. The Apollo 8
Apollo 8

Apollo 8 was the first manned space voyage to achieve a velocity sufficient to allow escape from the gravitational field of planet Earth; the first to escape from the gravitational field of another celestial body; and the first manned voyage to return to planet Earth from another celestial body....
 mission carried out the first manned trip to the Moon on 24 December 1968, certifying the Saturn V
Saturn V

The Saturn V was a multistage rocket liquid-fuel expendable launch system rocket used by NASA's Apollo program and Skylab programs from 1967 until 1973....
 booster for manned use and flying not a circumlunar loop but instead a full ten orbits around the Moon before returning safely to Earth. Apollo 10
Apollo 10

Apollo 10 was the fourth manned mission in the Apollo program. The mission included the second crew to orbit the Moon and an all-up test of the Apollo Lunar Module in lunar orbit....
 then performed a full dress rehearsal of a manned moon landing in May 1969. This mission stopped short at ten miles (16 km) altitude above the lunar surface, performing necessary low-altitude mapping of trajectory-altering mascons using a factory prototype lunar module that was too overweight to allow a successful landing. With the failure of the unmanned Soviet sample return moon landing attempt Luna 15
Luna 15

Luna 15 was an unmanned space mission of the Luna program, also called Lunik 15.Luna 15 was a last minute Soviet Union attempt to steal some of Apollo 11's publicity by being the first mission to return lunar soil to Earth....
 in July 1969, the stage was set for Apollo 11
Apollo 11

The Apollo 11 mission was the first manned mission to land on the Moon. It was the fifth human spaceflight of Apollo program and the third human voyage to the Moon....
.

American manned Moon landings (1969-1972)


American strategy


The U.S. Moon exploration program originated during the Eisenhower
Dwight D. Eisenhower

Dwight David ?Ike? Eisenhower was the List of Presidents of the United States President of the United States from 1953 until 1961 and a General of the Army in the United States Army....
 administration. In a series of mid-1950s articles in Collier's
Collier's Weekly

Collier's Weekly was an United States magazine founded by Peter Fenelon Collier and published from 1888 to 1957. With the passage of decades, the title was shortened to Collier's....
 magazine, Wernher von Braun
Wernher von Braun

Wernher Magnus Maximilian Freiherr von Braun , a Germans rocket physicist and astronautics engineer, became one of the leading figures in the development of rocket technology in Germany and the United States....
 had popularized the idea of a manned expedition to the Moon to establish a lunar base. A manned Moon landing posed several daunting technical challenges to the U.S. and USSR. Besides guidance and weight management, atmospheric re-entry without ablative
Ablation

Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosion processes. The term occurs in space physics associated with atmospheric reentry, in glaciology, medicine and passive fire protection....
 overheating was a major hurdle. After the Soviet Union's launch of Sputnik, von Braun promoted a plan for the United States Army to establish a military lunar outpost by 1965.

After the early Soviet successes
Space Race

File:Space race1.jpgThe Space Race was a competition of space exploration between the Soviet Union and the United States, which lasted roughly from 1957 to 1975....
, especially Yuri Gagarin
Yuri Gagarin

Yuri Alexeyevich Gagarin , Hero of the Soviet Union, was a Soviet Union cosmonaut. On 12 April 1961, he became the first human in space and the first to orbit the Earth....
's flight, U.S. President John F. Kennedy
John F. Kennedy

John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the List of Presidents of the United States President of the United States, serving from 1961 until John F....
 looked for an American project that would capture the public imagination. He asked Vice President Lyndon Johnson to make recommendations on a scientific endeavor that would prove U.S. world leadership. The proposals included non-space options such as massive irrigation projects to benefit the Third World
Third World

Third World is a categorical label used to describe states that are considered to be developed in terms of their economy or level of industrialization, globalization, standard of living, health, education or other criteria for 'advancements'....
. The Soviets, at the time, had more powerful rockets than the United States, which gave them an advantage in some kinds of space missions. Advances in U.S. nuclear weapons technology had led to smaller, lighter warheads, and consequently, rockets with smaller payload capacities. By comparison, Soviet nuclear weapons were much heavier, and the powerful R-7
R-7 Semyorka

The R-7 Semyorka was the world's first true intercontinental ballistic missile and was deployed by the Soviet Union during the Cold War from 1959 to 1968....
 rocket was developed to carry them. More modest potential missions such as flying around the Moon without landing or establishing a space lab in orbit (both were proposed by Kennedy to von Braun) were determined to offer too much advantage to the Soviets, since the U.S. would have to develop a heavy rocket to match the Soviets. A Moon landing, however, would capture world imagination while functioning as propaganda
Propaganda

Propaganda is the dissemination of information aimed at influencing the opinions or behaviors of large numbers of people. As opposed to Objectivity providing information, propaganda in its most basic sense presents information in order to influence its audience....
.

Mindful that the Apollo Program
Project Apollo

The Apollo program was a human spaceflight program undertaken by NASA during the years 1961?1975 with the goal of conducting manned moon landing missions....
 would economically benefit most of the key states in the next election—particularly his home state of Texas
Texas

Texas is a U.S. state located in the South Central United States, nicknamed the Lone Star State. Texas is the second largest U.S. state in both area and population, spanning , and with a growing population of 24.3 million residents....
 because NASA
NASA

The National Aeronautics and Space Administration is an agency of the Federal government of the United States, responsible for the nation's public list of space agencies....
's base was in Houston
Houston, Texas

Houston is the fourth-largest city in the United States of America and the largest city within the state of Texas. As of the 2007 U.S. Census estimate, the city has a population of 2.2 million within an area of 600 square miles ....
—Johnson championed the Apollo program. This superficially indicated action to alleviate the fictional "missile gap
Missile gap

The missile gap was the term used in the United States for the perceived disparity between the number and power of the weapons in the U.S.S.R. and United States ballistic missile arsenals during the Cold War....
" between the U.S. and USSR, a campaign promise of Kennedy's in the 1960 election. The Apollo project allowed continued development of dual-use technology. Johnson also advised that for anything less than a lunar landing the USSR had a good chance of beating the U.S. For these reasons, Kennedy seized on Apollo as the ideal focus for American efforts in space. He ensured continuing funding, shielding space spending from the 1963 tax cut and diverting money from other NASA projects. This dismayed NASA's leader, James E. Webb
James E. Webb

James Edwin Webb was the second administrator of NASA, serving from 14 February 1961 to 7 October 1968....
, who urged support for other scientific work.

In conversation with Webb, Kennedy said:

Everything we do ought to really be tied in to getting on to the moon ahead of the Russians [...] otherwise we shouldn't be spending that kind of money, because I'm not interested in space [...] The only justification for [the cost] is because we hope to beat [the USSR] to demonstrate that instead of being behind by a couple of years, by God, we passed them.


The Saturn V booster was the key to U.S. moon landings. It used more efficient liquid hydrogen fuel instead of kerosene in its upper stages in order to lift heavier payloads beyond Earth orbit. The Saturn had a perfect record of zero failures in thirteen launches. By contrast, the Soviet N-1 exploded in flight during four secret test launches and never achieved operational status.

Whatever he said in private, Kennedy needed a different message to gain public support to uphold what he was saying and his views. Later in 1963, Kennedy asked Vice President Johnson to investigate the possible technological and scientific benefits of a Moon mission. Johnson concluded that the benefits were limited, but, with the help of scientists at NASA, he put together a powerful case, citing possible medical breakthroughs and interesting pictures of Earth from space. For the program to succeed, its proponents would have to defeat criticism from politicians on the left, who wanted more money spent on social programs, and on those on the right, who favored a more military project. By emphasizing the scientific payoff and playing on fears of Soviet space dominance, Kennedy and Johnson managed to swing public opinion: by 1965, 58 percent of Americans favored Apollo, up from 33 percent two years earlier. After Johnson became President in 1963, his continuing defense of the program allowed it to succeed in 1969, as Kennedy had originally hoped.

Soviet strategy

Soviet leader Nikita Khrushchev
Nikita Khrushchev

Nikita Sergeyevich Khrushchev served as General Secretary of the Communist Party of the Soviet Union of the Communist Party of the Soviet Union from 1953 to 1964, following the death of Joseph Stalin, and Premier of the Soviet Union from 1958 to 1964....
 did not relish "defeat" by any other power, but equally did not relish funding such an expensive project. In October 1963 he said that the USSR was "not at present planning flight by cosmonauts to the Moon", while insisting that the Soviets had not dropped out of the race. Only after another year would the USSR fully commit itself to a Moon-landing attempt, which ultimately failed.

At the same time, Kennedy had suggested various joint programs, including a possible Moon landing by Soviet and American astronauts and the development of better weather-monitoring satellites. Khrushchev, sensing an attempt by Kennedy to steal Russian space technology, rejected the idea: if the USSR went to the Moon, it would go alone. Korolyov
Sergey Korolyov

Sergey Pavlovich Korolyov , , , was the head Soviet Union rocket engineer and designer during the Space Race between the United States of America and the Soviet Union in the 1950s and 1960s....
, the RSA's chief designer, had started promoting his Soyuz
Soyuz spacecraft

Soyuz ; English: Union) is a series of spacecraft designed for the Soviet space program by the S.P. Korolev Rocket and Space Corporation Energia....
 craft and the N-1 launcher rocket that would have the capability of carrying out a manned Moon landing. Khrushchev directed Korolyov's design bureau to arrange further space firsts by modifying the existing Vostok technology, while a second team started building a completely new launcher and craft, the Proton booster and the Zond, for a manned cislunar flight in 1966. In 1964 the new Soviet leadership gave Korolyov the backing for a Moon landing effort and brought all manned projects under his direction. With Korolyov's death and the failure of the first Soyuz flight in 1967, the co-ordination of the Soviet moon landing program quickly unraveled. The Soviets built a landing craft and selected cosmonauts for the mission that would have placed Aleksei Leonov
Aleksei Leonov

Alexey Arkhipovich Leonov , , is a retired Soviet Union/Russian astronaut and Soviet Air Forces General who, on March 18, 1965, became the first human to Extra-vehicular activity....
 on the Moon's surface, but with the successive launch failures of the N1 booster in 1969, plans for a manned landing suffered first delay and then cancellation.

Apollo Missions



In total twenty-four American astronauts have traveled to the Moon, with twelve walking on its surface and three making the trip twice. Apollo 8
Apollo 8

Apollo 8 was the first manned space voyage to achieve a velocity sufficient to allow escape from the gravitational field of planet Earth; the first to escape from the gravitational field of another celestial body; and the first manned voyage to return to planet Earth from another celestial body....
 was a lunar-orbit-only mission, Apollo 10
Apollo 10

Apollo 10 was the fourth manned mission in the Apollo program. The mission included the second crew to orbit the Moon and an all-up test of the Apollo Lunar Module in lunar orbit....
 included powered descent and then an abort-mode ascent of the LM, while Apollo 13
Apollo 13

Apollo 13 was the third manned lunar-landing mission, part of Project Apollo under NASA in the United States. The crew members were Commander Jim Lovell, Command Module pilot Jack Swigert, and Lunar Module pilot Fred W....
, originally scheduled as a landing, ended up as a lunar fly-by, by means of free return trajectory
Free return trajectory

A free return trajectory is one of a very small sub-class of trajectories in which the trajectory of a satellite traveling away from a primary body is modified by the presence of a secondary body causing the satellite to return to the primary body....
; thus, none of these missions made landings. Apollo 7
Apollo 7

Apollo 7 was the first manned mission in the Apollo program to be launched. It was an eleven-day Earth-orbital mission, the first manned launch of the Saturn IB launch vehicle, and the first three-man American space mission....
 and Apollo 9
Apollo 9

Apollo 9 was the first manned flight of the Apollo Command/Service Module along with the Apollo Lunar Module . Its three-person crew of Mission Commander Jim McDivitt, Command Module Pilot David Scott, and Lunar Module Pilot Rusty Schweickart tested several aspects critical to landing on the moon including the LM engines, backpack life suppo...
 never left Earth orbit. Apart from the inherent dangers of manned moon expeditions as seen with Apollo 13
Apollo 13

Apollo 13 was the third manned lunar-landing mission, part of Project Apollo under NASA in the United States. The crew members were Commander Jim Lovell, Command Module pilot Jack Swigert, and Lunar Module pilot Fred W....
, one reason for their cessation according to astronaut Alan Bean
Alan Bean

Alan LaVern Bean is a former NASA astronaut and became List of people who have walked on the Moon#People who have walked on the Moon at the age of thirty-seven years in November 1969....
 is the cost it imposes in government subsidies.

Human Moon Landings




Other aspects of the Apollo Moon landings

Unlike other international rivalries, the Space Race has remained unaffected in a direct way regarding the desire for territorial expansion. After the successful landings on the Moon, the U.S. explicitly disclaimed the right to ownership of any part of the Moon.

President Richard Nixon had speechwriter William Safire
William Safire

William L. Safire is an United States author, semi-retired columnist, and former journalist and President of the United States speechwriter.He is perhaps best known as a long-time print syndication political columnist for The New York Times and a regular contributor to "On Language" in the New York Times Magazine, a column on popul...
 prepare a condolence speech for delivery in the event that Armstrong and Aldrin became marooned on the Moon's surface and could not be rescued.

In the 1940s writer Arthur C Clarke forecast that man would reach the Moon by 2000.

On August 16, 2006, the Associated Press
Associated Press

The Associated Press is an Media of the United States news agency. The AP is a cooperative owned by its contributing newspapers, Radio station and Television station stations in the United States, which both contribute stories to the AP and use material written by its staffers....
 reported that NASA is currently missing the original
Apollo program missing tapes

The Apollo missing tapes are the missing original recordings of the transmissions broadcast during the Apollo 11 Extra-vehicular activity. The tapes included Slow-scan television and telemetry data....
 Slow-scan television
Slow-scan television

Slow-scan television is a picture transmission method used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color....
 tapes (which were made before the scan conversion for conventional TV) of the Apollo 11 Moon walk. Some news outlets have mistakenly reported that the SSTV tapes were found in Western Australia, but those tapes were only recordings of data from the Apollo 11 Early Apollo Surface Experiments Package
Apollo Lunar Surface Experiment Package

The Apollo Lunar Surface Experiments Package comprised a set of scientific instruments placed by the astronauts at the landing site of each of the five Apollo program to land on the Moon following Apollo 11 ....
.

Soviet unmanned soft landings (1969-1976)


Indian unmanned hard landings (2008-)

India
India

India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
 became the third country to reach the surface of the moon with a dedicated scientific probe when its lunar orbiting spacecraft Chandrayaan 1 released the Moon Impact Probe
Moon Impact Probe

The Moon Impact Probe developed by the Indian Space Research Organisation, India's national space agency, was a moon probe that was released by ISRO's Chandrayaan-1 Exploration of the Moon orbiter which in turn was launched, on 22nd October, 2008, aboard a modified version of ISRO's Polar Satellite Launch Vehicle....
. MIP reached the surface of the Moon at 2034 UT(0804 IST) on Nov 14 2008. This date was choosen to commemorate the birthday of Jawaharlal Nehru
Jawaharlal Nehru

Jawaharlal Nehru The son of the wealthy Indian barrister and politician Motilal Nehru, Nehru became a leader of the left-wing of the Indian National Congress at a remarkably young age....
, the first Indian Prime Minister who initiated India's space program. Developed in India by the Indian Space Research Organisation
Indian Space Research Organisation

The Indian Space Research Organisation is the primary body for space research under the control of the government of India. It was established in its modern form in 1969 as a result of coordinated efforts initiated earlier....
 (ISRO), the MIP had the Indian flag painted on its exterior. Although Japan
Japan

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south....
 and ESA had previously commanded their orbiters Hiten
Hiten

The Hiten spacecraft , built by the Institute of Space and Astronautical Science of Japan, was launched on January 24, 1990. It was Japan's first lunar probe, the first robotic lunar probe since the Soviet Union's Luna 24 in 1976, and the first lunar probe launched by a country other than Soviet Union or the United States....
 and SMART-1
SMART-1

SMART-1 was a Swedish-designed European Space Agency satellite that orbited around the Moon. It was launched on September 27, 2003 at 23:14 Coordinated Universal Time from the Guiana Space Centre in Kourou, French Guiana....
 to crash in selected zones on the Moon's surface at the end of their respective lifetimes, India's MIP was the first probe designed specifically for a trip to the lunar surface since the Soviet lander Luna 24
Luna 24

Luna 24 was an unmanned space mission of the Luna program, also called Lunik 24. The last of the Luna series of spacecraft, the mission of the Luna 24 probe was the third Soviet mission to retrieve Lunar soil samples ....
 in 1976.

Weighing 34 kilograms, the box shaped MIP carried three instruments – a video imaging system, a mass spectrometer and a radar altimeter. The video imaging system took pictures of the moon’s surface from high altitudes as MIP approached it, relaying those pictures back to Earth during the MIP's descent. The mass spectrometer made measurements of the extremely thin lunar atmosphere. The radar altimeter measured the rate of descent of the MIP probe to the lunar surface, testing that technology for future Indian soft landing missions. Such a soft landing is planned for 2010 or 2011 during the upcoming Chandrayaan 2 mission.

The Indian MIP-1 probe did not include braking rockets and was destroyed upon impacting the lunar surface at its planned speed of 3,100 miles per hour. Its achievement is roughly equivalent to the American Ranger 7 mission flown in 1964.

In popular culture

The moon landings are often referenced by Americans to criticize the failure of a government project or service. A typical example of this appears in the aftermath of a natural disaster: "We can land man on the moon and bring him back safely, but we can't stop a bit of floodwater".

Future plans

The next lunar orbiter currently scheduled for launch is NASA's Lunar Reconnaissance Orbiter mission. The Lunar Precursor Robotic Program (LPRP) is a program of robotic spacecraft missions which NASA
NASA

The National Aeronautics and Space Administration is an agency of the Federal government of the United States, responsible for the nation's public list of space agencies....
 will use to prepare for future human spaceflight
Human spaceflight

A human spaceflight is a spaceflight with a Astronaut, and possibly passengers. This makes it unlike Robotic spacecraft space probes or remotely-controlled satellites....
 missions to the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
. Two LPRP missions, the Lunar Reconnaissance Orbiter
Lunar Reconnaissance Orbiter

The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon....
 (LRO) and the Lunar CRater Observation and Sensing Satellite (LCROSS
Lunar Reconnaissance Orbiter

The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon....
), are scheduled to launch early in 2009.

Russia plans to send cosmonauts to the Moon by 2025 and establish a permanent manned base there in 2027-2032.

ISRO, the India
India

India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
n National Space agency, has announced the Chandrayaan
Chandrayaan

Chandrayaan-1, is India's first mission to the Moon launched by India's national space agency the Indian Space Research Organisation. The unmanned Exploration of the Moon mission includes a lunar orbiter and an impactor....
 program for Lunar exploration. The second mission Chandrayaan II plans to land a motorised rover by 2010/2011.

Other nations, including China, have expressed interest in pursuing human landings on the Moon, but none have currently announced formal plans.

The Google Lunar X Prize
Google Lunar X Prize

The Google Lunar X PRIZE, sometimes referred to as simply Moon 2.0, is a space competition organized by the X PRIZE Foundation, and sponsored by Google....
 competition offers a $20 million award for the first privately-funded team to land a robotic probe on the Moon. Like the Ansari X Prize
Ansari X Prize

The Ansari X PRIZE was a space competition in which the X PRIZE Foundation offered a United States dollar10,000,000 prize for the first Non-governmental organization to launch a reusable manned spaceflight into outer space twice within two weeks....
 before it, the competition aims to advance the state of the art in private space exploration.

Hoax accusations

Some conspiracy theorists
Conspiracy theory

A conspiracy theory alleges a coordinated group is, or was, secretly working to commit illegal or wrongful actions, including attempting to hide the existence of the group and its activities....
 have insisted that the Apollo moon landings were a hoax. These accusations flourish in part because predictions by enthusiasts that Moon landings would become commonplace have not yet come to pass. Some claims can be empirically
Empiricism

In philosophy, empiricism is a theory of knowledge which asserts that knowledge arises from experience. Empiricism is one of several competing views about how we know "things," part of the branch of philosophy called epistemology, or "theory of knowledge"....
 discredited by three retroreflector
Retroreflector

A retroreflector is a device or surface that Reflection light back to its source with a minimum scattering of light. An electromagnetic wave front is reflected back along a vector that is parallel to but opposite in direction from the wave's source....
 arrays left on the Moon by Apollo 11, 14 and 15. Today, anyone on Earth with an appropriate laser
Laser

A laser is a device that emits light through a process called stimulated emission. The term laser is an acronym for light amplification by stimulated emission of radiation....
 and telescope
Telescope

A telescope is an instrument designed for the observation of remote objects by the collection of electromagnetic radiation. The first known practically functioning telescopes were invented in the Netherlands at the beginning of the 17th century....
 system may bounce laser beams off these devices, verifying deployment of the Lunar Laser Ranging Experiment
Lunar laser ranging experiment

The ongoing Lunar Laser Ranging Experiment measures the Lunar distance between the Earth and the Moon using LIDAR. Lasers on Earth are aimed at retroreflectors previously planted on the Moon and the time delay for the reflected light to return is determined....
 at historically documented Apollo moon landing sites. This evidence gives strong standing to Man-Made devices having made successful landings. The Mythbusters
MythBusters

MythBusters is a popular science television program produced by Australian firm Beyond Television Productions originally for the Discovery Channel in the United States and Canada....
 have tried to determine if the Moon Landing really was a hoax which included some of these experiments, why the footprint was so clear, why the flag was waving and why Neil Armstrong was viewed so clearly while the section was in a shadow (see MythBusters (2008 season)#Episode 104 – "NASA Moon Landing").

See also

  • Apollo program missing tapes
    Apollo program missing tapes

    The Apollo missing tapes are the missing original recordings of the transmissions broadcast during the Apollo 11 Extra-vehicular activity. The tapes included Slow-scan television and telemetry data....
  • Independent evidence for Apollo Moon landings
    Independent evidence for Apollo Moon landings

    Independent evidence for Apollo Moon landings is evidence from independent groups that supports the idea that NASA conducted manned Moon landings....
  • Luna programme
    Luna programme

    The Luna programme , occasionally called Lunik or Lunnik, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976....
  • Lunokhod program
  • Project Apollo
    Project Apollo

    The Apollo program was a human spaceflight program undertaken by NASA during the years 1961?1975 with the goal of conducting manned moon landing missions....
  • Soviet Moonshot
    Soviet Moonshot

    "Moonshot" redirects here.'For the Buffy Sainte-Marie album, see Moonshot .Details of the Soviet Union Moonshot were kept intensely secret until the arrival of glasnost....


External links

  • on moon landings, missions, etc. (includes information on other space agencies' missions