Soviet space program
The Soviet space program comprised several of the rocket and space exploration programs conducted by the Soviet Union from the 1930s until its collapse in 1991. Over its 60-year history, this classified military program was responsible for a number of pioneering accomplishments in space flight, including the first intercontinental ballistic missile, first satellite, first animal in Earth orbit, first human in space and Earth orbit, first woman in space and Earth orbit, first spacewalk, first Moon impact, first image of the far side of the Moon and unmanned lunar soft landing, first space rover, first sample of lunar soil automatically extracted and brought to Earth, first space station. Further notable records included the first interplanetary probes: Venera 1 and Mars 1 to fly by Venus and Mars Venera 3 and Mars 2 to impact the respective planet surface, Venera 7 and Mars 3 to make soft landings on these planets; the rocket and space program of the USSR boosted by the assistance of captured scientists from the advanced German rocket program, was performed by Soviet engineers and scientists after 1955, was based on some unique Soviet and Imperial Russian theoretical developments, many derived by Konstantin Tsiolkovsky, sometimes known as the father of theoretical astronautics.
Sergey Korolev was the head of the principal design group. Unlike its American competitor in the "Space Race", which had NASA as a single coordinating agency, the USSR's program was split among several competing design bureaus led by Korolev, Mikhail Yangel, Valentin Glushko, Vladimir Chelomei; because of the program's classified status, for propaganda value, announcements of the outcomes of missions were delayed until success was certain, failures were sometimes kept secret. As a result of Mikhail Gorbachev's policy of glasnost in the 1980s, many facts about the space program were declassified. Notable setbacks included the deaths of Korolev, Vladimir Komarov, Yuri Gagarin between 1966 and 1968, development failure of the huge N-1 rocket intended to power a manned lunar landing, which exploded shortly after lift-off on four unmanned tests. With the collapse of the Soviet Union and Ukraine inherited the program. Russia created the Russian Aviation and Space Agency, now known as the Roscosmos State Corporation, while Ukraine created the National Space Agency of Ukraine.
The theory of space exploration had a solid basis in the Russian Empire before the First World War with the writings of Konstantin Tsiolkovsky, who published pioneering papers in the late 19th and early 20th centuries and in 1929 introduced the concept of the multistaged rocket. Practical aspects built on early experiments carried out by members of the reactive propulsion study group, GIRD in the 1920s and 1930s, where such pioneers as Sergey Korolev—who dreamed of traveling to Mars—and the German-Russian engineer Friedrich Zander worked. On August 18, 1933, GIRD launched the first Soviet liquid-fueled rocket Gird-09, on November 25, 1933, the first hybrid-fueled rocket GIRD-X. In 1940-41 another advance in the reactive propulsion field took place: the development and serial production of the Katyusha multiple rocket launcher. During the 1930s Soviet rocket technology was comparable to Germany's, but Joseph Stalin's Great Purge damaged its progress. Many leading engineers were killed, Korolev and others were imprisoned in the Gulag.
Although the Katyusha was effective on the Eastern Front during World War II, the advanced state of the German rocket program amazed Soviet engineers who inspected its remains at Peenemünde and Mittelwerk after the end of the war in Europe. The Americans had secretly moved most leading German scientists and 100 V-2 rockets to the United States in Operation Paperclip, but the Soviet program benefited from captured German records and scientists, in particular drawings obtained from the V-2 production sites. Under the direction of Dimitri Ustinov and others inspected the drawings. Helped by rocket scientist Helmut Gröttrup and other captured Germans until the early 1950s, they built a replica of the V-2 called the R-1, although the weight of Soviet nuclear warheads required a more powerful booster. Korolev's OKB-1 design bureau was dedicated to the liquid-fueled cryogenic rockets he had been experimenting with in the late 1930s; this work resulted in the design of the R-7 Semyorka intercontinental ballistic missile, tested in August 1957.
The Soviet space program was tied to the USSR's Five-Year Plans and from the start was reliant on support from the Soviet military. Although he was "single-mindedly driven by the dream of space travel", Korolev kept this a secret while working on military projects—especially, after the Soviet Union's first atomic bomb test in 1949, a missile capable of carrying a nuclear warhead to the United States—as many mocked the idea of launching satellites and manned spacecraft. Nonetheless, the first Soviet rocket with animals aboard launched in July 1951. Two months ahead of America's first such achievement and subsequent flights gave the Soviets valuable experience with space medicine; because of its global range and large payl
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, the largest among planetary satellites relative to the size of the planet that it orbits; the Moon is after Jupiter's satellite Io the second-densest satellite in the Solar System among those whose densities are known. The Moon is thought to have formed not long after Earth; the most accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia. The Moon is in synchronous rotation with Earth, thus always shows the same side to Earth, the near side; the near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest visible celestial object in Earth's sky, its surface is dark, although compared to the night sky it appears bright, with a reflectance just higher than that of worn asphalt.
Its gravitational influence produces the ocean tides, body tides, the slight lengthening of the day. The Moon's average orbital distance is 1.28 light-seconds. This is about thirty times the diameter of Earth; the Moon's apparent size in the sky is the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly during a total solar eclipse; this matching of apparent visual size will not continue in the far future because the Moon's distance from Earth is increasing. The Moon was first reached in September 1959 by an unmanned spacecraft; the United States' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, six manned landings between 1969 and 1972, with the first being Apollo 11. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon's origin, internal structure, the Moon's history. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.
Both the Moon's natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences can be found in language, lunar calendar systems and mythology; the usual English proper name for Earth's natural satellite is "the Moon", which in nonscientific texts is not capitalized. The noun moon is derived from Old English mōna, which stems from Proto-Germanic *mēnô, which comes from Proto-Indo-European *mḗh₁n̥s "moon", "month", which comes from the Proto-Indo-European root *meh₁- "to measure", the month being the ancient unit of time measured by the Moon; the name "Luna" is used. In literature science fiction, "Luna" is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of Earth's moon; the modern English adjective pertaining to the Moon is lunar, derived from the Latin word for the Moon, luna. The adjective selenic is so used to refer to the Moon that this meaning is not recorded in most major dictionaries.
It is derived from the Ancient Greek word for the Moon, σελήνη, from, however derived the prefix "seleno-", as in selenography, the study of the physical features of the Moon, as well as the element name selenium. Both the Greek goddess Selene and the Roman goddess Diana were alternatively called Cynthia; the names Luna and Selene are reflected in terminology for lunar orbits in words such as apolune and selenocentric. The name Diana comes from the Proto-Indo-European *diw-yo, "heavenly", which comes from the PIE root *dyeu- "to shine," which in many derivatives means "sky and god" and is the origin of Latin dies, "day"; the Moon formed 4.51 billion years ago, some 60 million years after the origin of the Solar System. Several forming mechanisms have been proposed, including the fission of the Moon from Earth's crust through centrifugal force, the gravitational capture of a pre-formed Moon, the co-formation of Earth and the Moon together in the primordial accretion disk; these hypotheses cannot account for the high angular momentum of the Earth–Moon system.
The prevailing hypothesis is that the Earth–Moon system formed after an impact of a Mars-sized body with the proto-Earth. The impact blasted material into Earth's orbit and the material accreted and formed the Moon; the Moon's far side has a crust, 30 mi thicker than that of the near side. This is thought to be; this hypothesis, although not perfect best explains the evidence. Eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, Jeff Taylor challenged fellow lunar scientists: "You have eighteen months. Go back to your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don't come to our conference unless you have something to say about the Moon's birth." At the 1984 conference at Kona, the giant impact hypothesis emerged as the most consensual theory. Before the conference, there were parti
A spacecraft is a vehicle or machine designed to fly in outer space. Spacecraft are used for a variety of purposes, including communications, earth observation, navigation, space colonization, planetary exploration, transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, require a launch vehicle. On a sub-orbital spaceflight, a space vehicle enters space and returns to the surface, without having gained sufficient energy or velocity to make a full orbit of the Earth. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific research are space probes. Robotic spacecraft that remain in orbit around a planetary body are artificial satellites.
To date, only a handful of interstellar probes, such as Pioneer 10 and 11, Voyager 1 and 2, New Horizons, are on trajectories that leave the Solar System. Orbital spacecraft may be recoverable or not. Most are not. Recoverable spacecraft may be subdivided by method of reentry to Earth into non-winged space capsules and winged spaceplanes. Humanity has achieved space flight but only a few nations have the technology for orbital launches: Russia, the United States, the member states of the European Space Agency, China, Taiwan (National Chung-Shan Institute of Science and Technology, Taiwan National Space Organization, Israel and North Korea. A German V-2 became the first spacecraft when it reached an altitude of 189 km in June 1944 in Peenemünde, Germany. Sputnik 1 was the first artificial satellite, it was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957. The launch ushered in new political, military and scientific developments. Apart from its value as a technological first, Sputnik 1 helped to identify the upper atmospheric layer's density, through measuring the satellite's orbital changes.
It provided data on radio-signal distribution in the ionosphere. Pressurized nitrogen in the satellite's false body provided the first opportunity for meteoroid detection. Sputnik 1 was launched during the International Geophysical Year from Site No.1/5, at the 5th Tyuratam range, in Kazakh SSR. The satellite travelled at 29,000 kilometers per hour, taking 96.2 minutes to complete an orbit, emitted radio signals at 20.005 and 40.002 MHz While Sputnik 1 was the first spacecraft to orbit the Earth, other man-made objects had reached an altitude of 100 km, the height required by the international organization Fédération Aéronautique Internationale to count as a spaceflight. This altitude is called the Kármán line. In particular, in the 1940s there were several test launches of the V-2 rocket, some of which reached altitudes well over 100 km; as of 2016, only three nations have flown crewed spacecraft: USSR/Russia, USA, China. The first crewed spacecraft was Vostok 1, which carried Soviet cosmonaut Yuri Gagarin into space in 1961, completed a full Earth orbit.
There were five other crewed missions. The second crewed spacecraft was named Freedom 7, it performed a sub-orbital spaceflight in 1961 carrying American astronaut Alan Shepard to an altitude of just over 187 kilometers. There were five other crewed missions using Mercury spacecraft. Other Soviet crewed spacecraft include the Voskhod, flown uncrewed as Zond/L1, L3, TKS, the Salyut and Mir crewed space stations. Other American crewed spacecraft include the Gemini spacecraft, Apollo spacecraft, the Skylab space station, the Space Shuttle with undetached European Spacelab and private US Spacehab space stations-modules. China developed, but did not fly Shuguang, is using Shenzhou. Except for the Space Shuttle, all of the recoverable crewed orbital spacecraft were space capsules. Crewed space capsules The International Space Station, crewed since November 2000, is a joint venture between Russia, the United States and several other countries; some reusable vehicles have been designed only for crewed spaceflight, these are called spaceplanes.
The first example of such was the North American X-15 spaceplane, which conducted two crewed flights which reached an altitude of over 100 km in the 1960s. The first reusable spacecraft, the X-15, was air-launched on a suborbital trajectory on July 19, 1963; the first reusable orbital spacecraft, a winged non-capsule, the Space Shuttle, was launched by the USA on the 20th anniversary of Yuri Gagarin's flight, on April 12, 1981. During the Shuttle era, six orbiters were built, all of which have flown in the atmosphere and five of which have flown in space. Enterprise was used only for approach and landing tests, launching from the back of a Boeing 747 SCA and gliding to deadstick landings at Edwards AFB, California; the first Space Shuttle to fly into space was Columbia, followed by Challenger, Discovery and Endeavour. Endeavour was built to replace Challenger when it was lost in January 1986. Columbia broke up during reentry in February 2003; the first automatic reusable spacecraft was the Buran-class shuttle, launched by the USSR on November 15, 1988, although it made only one flight and this was uncrewed.
This spaceplane was designed for a crew and resembled the U
In astronomy, lunar orbit is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by various manned or unmanned spacecraft around the Moon; the altitude at apoapsis for a lunar orbit is known as apolune, apocynthion, or aposelene, while the periapsis is known as perilune, pericynthion, or periselene, from names or epithets of the moon goddess. Low lunar orbit —orbits below 100 km altitude—are of particular interest in exploration of the Moon, but suffer from gravitational perturbation effects that make most unstable, leave only a few orbital inclinations possible for indefinite frozen orbits, useful for long-term stays in LLO; the Soviet Union sent the first spacecraft to the vicinity of the Moon, the robotic vehicle Luna 1, on January 4, 1959. It did not achieve lunar orbit. Luna 3, launched on October 4, 1959, was the first robotic spacecraft to complete a circumlunar free return trajectory, still not a lunar orbit, but a figure-8 trajectory which swung around the far side of the Moon and returned to the Earth.
This craft provided the first pictures of the far side of the Lunar surface. The Soviet Luna 10 became the first spacecraft to orbit the Moon in April 1966, it studied micrometeoroid flux, lunar environment until May 30, 1966. A follow-on mission, Luna 11, was launched on August 24, 1966 and studied lunar gravitational anomalies and solar wind measurements; the first United States spacecraft to orbit the Moon was Lunar Orbiter 1 on August 14, 1966. The first orbit was an elliptical orbit, with an apolune of 1,008 nautical miles and a perilune of 102.1 nautical miles. The orbit was circularized at around 170 nautical miles to obtain suitable imagery. Five such spacecraft were launched over a period of thirteen months, all of which mapped the Moon for the purpose of finding suitable Apollo program landing sites; the most recent was the Lunar Atmosphere and Dust Environment Explorer, which became a ballistic impact experiment in 2014. The Apollo program's Command/Service Module remained in a lunar parking orbit while the Lunar Module landed.
The combined CSM/LM would first enter an elliptical orbit, nominally 170 nautical miles by 60 nautical miles, changed to a circular parking orbit of about 60 nautical miles. Orbital periods vary according to the sum of apoapsis and periapsis, for the CSM were about two hours; the LM began its landing sequence with a Descent Orbit Insertion burn to lower their periapsis to about 50,000 feet, chosen to avoid hitting lunar mountains reaching heights of 20,000 feet. After the second landing mission, the procedure was changed on Apollo 14 to save more of the LM fuel for its powered descent, by using the CSM's fuel to perform the DOI burn, raising its periapsis back to a circular orbit after the LM had made its landing. Gravitational anomalies distorting the orbits of some Lunar Orbiters led to the discovery of mass concentrations beneath the lunar surface caused by large impacting bodies at some remote time in the past; these anomalies are of sufficient magnitude to cause a lunar orbit to change over the course of several days.
The Apollo 11 first manned landing mission employed the first attempt to correct for the perturbation effect. The parking orbit was "circularized" at 66 nautical miles by 54 nautical miles, expected to become the nominal circular 60 nautical miles when the LM made its return rendezvous with the CSM, but the effect was overestimated by a factor of two. Study of the mascons' effect on lunar spacecraft led to the discovery in 2001 of "frozen orbits" occurring at four orbital inclinations: 27°, 50°, 76°, 86°, in which a spacecraft can stay in a low orbit indefinitely; the Apollo 15 subsatellite PFS-1 and the Apollo 16 subsatellite PFS-2, both small satellites released from the Apollo Service Module, contributed to this discovery. PFS-1 ended up in a long-lasting orbit, at 28° inclination, completed its mission after one and a half years. PFS-2 was placed in a unstable orbital inclination of 11°, lasted only 35 days in orbit before crashing into the lunar surface. List of orbits Mass concentration Orbital mechanics
Lunar Orbiter 1
The Lunar Orbiter 1 robotic spacecraft, part of NASA's Lunar Orbiter program, was the first American spacecraft to orbit the Moon. It was designed to photograph smooth areas of the lunar surface for selection and verification of safe landing sites for the Surveyor and Apollo missions, it was equipped to collect selenodetic, radiation intensity, micrometeoroid impact data. Mission controllers injected the spacecraft into a parking orbit around Earth on August 10, 1966, at 19:31 UTC; the trans-lunar injection burn occurred at 20:04 UTC. The spacecraft experienced a temporary failure of the Canopus star tracker and overheating during its cruise to the Moon; the star tracker problem was resolved by navigating using the Moon as a reference, the overheating was abated by orienting the spacecraft 36 degrees off-Sun to lower the temperature. Lunar Orbiter 1 was injected into an elliptical near-equatorial lunar orbit 92.1 hours after launch. The initial orbit was 189.1 by 1,866.8 kilometers and had a period of 3 hours 37 minutes and an inclination of 12.2 degrees.
On August 21, perilune was dropped on August 25 to 40.5 km. The spacecraft acquired photographic data from August 18 to 29, 1966, readout occurred through September 14, 1966. A total of 42 high-resolution and 187 medium-resolution frames were taken and transmitted to Earth covering more than 5 million square kilometers of the Moon's surface, accomplishing about 75% of the intended mission, although a number of the early high-resolution photos showed severe smearing, it took the first two pictures of Earth from the distance of the Moon. Accurate data were acquired from all other experiments throughout the mission. Orbit tracking showed a slight "pear-shape" of the Moon based on the gravity field, no micrometeorite impacts were detected; the spacecraft was tracked until it impacted the lunar surface on command at 7 degrees north latitude, 161 degrees east longitude on the Moon's far side on October 29, 1966, on its 577th orbit. The early end of the nominal one-year mission resulted from a shortage of remaining attitude control gas and other deteriorating conditions and was planned to avoid transmission interference with Lunar Orbiter 2.
Lunar Orbiter Image Recovery Project Exploration of the Moon Lunar Orbiter 2 Lunar Orbiter 3 Lunar Orbiter 4 Lunar Orbiter 5 Destination Moon: A History of the Lunar Orbiter Program by the NASA History Office Lunar Orbiter Photo Gallery - Mission 1 by the Lunar and Planetary Institute
The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research. NASA was established in 1958; the new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles; the agency is responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA science is focused on better understanding Earth through the Earth Observing System. From 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1.
In the early 1950s, there was challenge to launch an artificial satellite for the International Geophysical Year. An effort for this was the American Project Vanguard. After the Soviet launch of the world's first artificial satellite on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts; the US Congress, alarmed by the perceived threat to national security and technological leadership, urged immediate and swift action. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge be met by an energetic program of research and development for the conquest of space... It is accordingly proposed that the scientific research be the responsibility of a national civilian agency...
NACA is capable, by rapid extension and expansion of its effort, of providing leadership in space technology. While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency was created in February 1958 to develop space technology for military application. On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA; when it began operations on October 1, 1958, NASA absorbed the 43-year-old NACA intact. A NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA. A significant contributor to NASA's entry into the Space Race with the Soviet Union was the technology from the German rocket program led by Wernher von Braun, now working for the Army Ballistic Missile Agency, which in turn incorporated the technology of American scientist Robert Goddard's earlier works. Earlier research efforts within the US Air Force and many of ARPA's early space programs were transferred to NASA.
In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology. The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee is associated with the President's political party, a new administrator is chosen when the Presidency changes parties; the only exceptions to this have been: Democrat Thomas O. Paine, acting administrator under Democrat Lyndon B. Johnson, stayed on while Republican Richard Nixon tried but failed to get one of his own choices to accept the job. Paine was confirmed by the Senate in March 1969 and served through September 1970. Republican James C. Fletcher, appointed by Nixon and confirmed in April 1971, stayed through May 1977 into the term of Democrat Jimmy Carter. Daniel Goldin was appointed by Republican George H. W. Bush and stayed through the entire administration of Democrat Bill Clinton.
Robert M. Lightfoot, Jr. associate administrator under Democrat Barack Obama, was kept on as acting administrator by Republican Donald Trump until Trump's own choice Jim Bridenstine, was confirmed in April 2018. Though the agency is independent, the survival or discontinuation of projects can depend directly on the will of the President; the first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research; the second administrator, James E. Webb, appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's Moon la
The Apollo program known as Project Apollo, was the third United States human spaceflight program carried out by the National Aeronautics and Space Administration, which succeeded in landing the first humans on the Moon from 1969 to 1972. First conceived during Dwight D. Eisenhower's administration as a three-man spacecraft to follow the one-man Project Mercury which put the first Americans in space, Apollo was dedicated to President John F. Kennedy's national goal of "landing a man on the Moon and returning him safely to the Earth" by the end of the 1960s, which he proposed in an address to Congress on May 25, 1961, it was the third US human spaceflight program to fly, preceded by the two-man Project Gemini conceived in 1961 to extend spaceflight capability in support of Apollo. Kennedy's goal was accomplished on the Apollo 11 mission when astronauts Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module on July 20, 1969, walked on the lunar surface, while Michael Collins remained in lunar orbit in the command and service module, all three landed safely on Earth on July 24.
Five subsequent Apollo missions landed astronauts on the Moon, the last in December 1972. In these six spaceflights, twelve men walked on the Moon. Apollo ran from 1961 to 1972, with the first manned flight in 1968, it achieved its goal of manned lunar landing, despite the major setback of a 1967 Apollo 1 cabin fire that killed the entire crew during a prelaunch test. After the first landing, sufficient flight hardware remained for nine follow-on landings with a plan for extended lunar geological and astrophysical exploration. Budget cuts forced the cancellation of three of these. Five of the remaining six missions achieved successful landings, but the Apollo 13 landing was prevented by an oxygen tank explosion in transit to the Moon, which destroyed the service module's capability to provide electrical power, crippling the CSM's propulsion and life support systems; the crew returned to Earth safely by using the lunar module as a "lifeboat" for these functions. Apollo used Saturn family rockets as launch vehicles, which were used for an Apollo Applications Program, which consisted of Skylab, a space station that supported three manned missions in 1973–74, the Apollo–Soyuz Test Project, a joint US-Soviet Union Earth-orbit mission in 1975.
Apollo set several major human spaceflight milestones. It stands alone in sending manned missions beyond low Earth orbit. Apollo 8 was the first manned spacecraft to orbit another celestial body, while the final Apollo 17 mission marked the sixth Moon landing and the ninth manned mission beyond low Earth orbit; the program returned 842 pounds of lunar rocks and soil to Earth contributing to the understanding of the Moon's composition and geological history. The program laid the foundation for NASA's subsequent human spaceflight capability and funded construction of its Johnson Space Center and Kennedy Space Center. Apollo spurred advances in many areas of technology incidental to rocketry and manned spaceflight, including avionics, telecommunications, computers; the Apollo program was conceived during the Eisenhower administration in early 1960, as a follow-up to Project Mercury. While the Mercury capsule could only support one astronaut on a limited Earth orbital mission, Apollo would carry three astronauts.
Possible missions included ferrying crews to a space station, circumlunar flights, eventual manned lunar landings. The program was named after Apollo, the Greek god of light and the sun, by NASA manager Abe Silverstein, who said that "I was naming the spacecraft like I'd name my baby." Silverstein chose the name at home one evening, early in 1960, because he felt "Apollo riding his chariot across the Sun was appropriate to the grand scale of the proposed program."In July 1960, NASA Deputy Administrator Hugh L. Dryden announced the Apollo program to industry representatives at a series of Space Task Group conferences. Preliminary specifications were laid out for a spacecraft with a mission module cabin separate from the command module, a propulsion and equipment module. On August 30, a feasibility study competition was announced, on October 25, three study contracts were awarded to General Dynamics/Convair, General Electric, the Glenn L. Martin Company. Meanwhile, NASA performed its own in-house spacecraft design studies led by Maxime Faget, to serve as a gauge to judge and monitor the three industry designs.
In November 1960, John F. Kennedy was elected president after a campaign that promised American superiority over the Soviet Union in the fields of space exploration and missile defense. Up to the election of 1960, Kennedy had been speaking out against the "missile gap" that he and many other senators felt had developed between the Soviet Union and United States due to the inaction of President Eisenhower. Beyond military power, Kennedy used aerospace technology as a symbol of national prestige, pledging to make the US not "first but, first and, first if, but first period." Despite Kennedy's rhetoric, he did not come to a decision on the status of the Apollo program once he became president. He knew little about the technical details of the space program, was put off by the massive financial commitment required by a manned Moon landing; when Kennedy's newly appointed NASA Administrator James E. Webb requested a 30 percent budget increase for his agency, Kennedy supported an acceleration of NASA's large booster program but deferred a decision on the broader issue.
On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person to fly in space, reinforcing American fears about being left behind in a technological competition with the Soviet Union. At a meeting of the US House Committee on Science and Astronaut