The National Aeronautics and Space Administration (NASA, /ˈnæsə/) is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research.[note 1]
NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA). The new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science.[7][8][9] Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, and later 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 also responsible for the Launch Services Program which provides oversight of launch operations and countdown management for uncrewed NASA launches.
NASA science is focused on better understanding Earth through the Earth Observing System;[10] advancing heliophysics through the efforts of the Science Mission Directorate's Heliophysics Research Program;[11] exploring bodies throughout the Solar System with advanced robotic spacecraft missions such as New Horizons;[12] and researching astrophysics topics, such as the Big Bang, through the Great Observatories and associated programs
From 1946, the National Advisory Committee for Aeronautics (NACA) had been experimenting with rocket planes such as the supersonic Bell X-1.[14] In the early 1950s, there was a challenge to launch an artificial satellite for the International Geophysical Year (1957–58), resulting in the American Project Vanguard among others. After the Soviet launch of the world's first artificial satellite (Sputnik 1) 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 (known as the "Sputnik crisis"), urged immediate and swift action; President Dwight D. Eisenhower and his advisers counseled more deliberate measures. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever.[9] 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 [Sputnik] 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.[15]
While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency (ARPA) was created in February 1958 to develop space technology for military application.[16]
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; its 8,000 employees, an annual budget of US$100 million, three major research laboratories (Langley Aeronautical Laboratory, Ames Aeronautical Laboratory, and Lewis Flight Propulsion Laboratory) and two small test facilities.[17] A NASA seal was approved by President Eisenhower in 1959.[18] 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, who was now working for the Army Ballistic Missile Agency (ABMA), which in turn incorporated the technology of American scientist Robert Goddard's earlier works.[19] Earlier research efforts within the US Air Force[17] and many of ARPA's early space programs were also transferred to NASA.[20] In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology.[17]
Leadership
The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, and reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee usually is associated with the President's political party (Democratic or Republican), and a new administrator is usually 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.[21]
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.[22]
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.[23]
The second administrator, James E. Webb (1961–1968), 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 landing goal by the end of the 1960s, Webb directed major management restructuring and facility expansion, establishing the Houston Manned Spacecraft (Johnson) Center and the Florida Launch Operations (Kennedy) Center. Capitalizing on Kennedy's legacy, President Lyndon Johnson kept continuity with the Apollo program by keeping Webb on when he succeeded Kennedy in November 1963. But Webb resigned in October 1968 before Apollo achieved its goal, and Republican President Richard M. Nixon replaced Webb with Republican Thomas O. Paine.
James Fletcher was responsible for early planning of the Space Shuttle program during his first term as administrator under President Nixon. He was appointed for a second term as administrator from May 1986 through April 1989 by President Ronald Reagan to help the agency recover from the Space Shuttle Challenger disaster.
Former astronaut Charles Bolden served as NASA's twelfth administrator from July 2009 to January 20, 2017.[24] Bolden is one of three former astronauts who became NASA administrators, along with Richard H. Truly (served 1989–1992) and Frederick D. Gregory (acting, 2005).
The agency's administration is located at NASA Headquarters in Washington, DC and provides overall guidance and direction.[25] Except under exceptional circumstances, NASA civil service employees are required to be citizens of the United States.[26]
Space flight programs
NASA has conducted many crewed and uncrewed spaceflight programs throughout its history. Uncrewed programs launched the first American artificial satellites into Earth orbit for scientific and communications purposes, and sent scientific probes to explore the planets of the solar system, starting with Venus and Mars, and including "grand tours" of the outer planets. Crewed programs sent the first Americans into low Earth orbit (LEO), won the Space Race with the Soviet Union by landing twelve men on the Moon from 1969 to 1972 in the Apollo program, developed a semi-reusable LEO Space Shuttle, and developed LEO space station capability by itself and with the cooperation of several other nations including post-Soviet Russia. Some missions include both crewed and uncrewed aspects, such as the Galileo probe, which was deployed by astronauts in Earth orbit before being sent uncrewed to Jupiter.
Crewed programs
The experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for crewed spaceflight. This was followed by a one-man space capsule program, and in turn by a two-man capsule program. Reacting to loss of national prestige and security fears caused by early leads in space exploration by the Soviet Union, in 1961 President John F. Kennedy proposed the ambitious goal "of landing a man on the Moon by the end of [the 1960s], and returning him safely to the Earth." This goal was met in 1969 by the Apollo program, and NASA planned even more ambitious activities leading to a human mission to Mars. However, reduction of the perceived threat and changing political priorities almost immediately caused the termination of most of these plans. NASA turned its attention to an Apollo-derived temporary space laboratory, and a semi-reusable Earth orbital shuttle. In the 1990s, funding was approved for NASA to develop a permanent Earth orbital space station in cooperation with the international community, which now included the former rival, post-Soviet Russia. To date, NASA has launched a total of 166 crewed space missions on rockets, and thirteen X-15 rocket flights above the USAF definition of spaceflight altitude, 260,000 feet (80 km).[28]
X-15 rocket plane (1959–1968)
The North American X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force and Navy. The design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems.[29] Requests for proposal were issued on December 30, 1954, for the airframe, and February 4, 1955, for the rocket engine. The airframe contract was awarded to North American Aviation in November 1955, and the XLR30 engine contract was awarded to Reaction Motors in 1956, and three planes were built. The X-15 was drop-launched from the wing of one of two NASA Boeing B-52 Stratofortresses, NB52A tail number 52-003, and NB52B, tail number 52-008 (known as the Balls 8). Release took place at an altitude of about 45,000 feet (14 km) and a speed of about 500 miles per hour (805 km/h).
Twelve pilots were selected for the program from the Air Force, Navy, and NACA (later NASA). A total of 199 flights were made between 1959 and 1968, resulting in the official world record for the highest speed ever reached by a crewed powered aircraft (current as of 2014), and a maximum speed of Mach 6.72, 4,519 miles per hour (7,273 km/h).[30] The altitude record for X-15 was 354,200 feet (107.96 km).[31] Eight of the pilots were awarded Air Force astronaut wings for flying above 260,000 feet (80 km), and two flights by Joseph A. Walker exceeded 100 kilometers (330,000 ft), qualifying as spaceflight according to the International Aeronautical Federation. The X-15 program employed mechanical techniques used in the later crewed spaceflight programs, including reaction control system jets for controlling the orientation of a spacecraft, space suits, and horizon definition for navigation.[31] The reentry and landing data collected were valuable to NASA for designing the Space Shuttle.[29]
Project Mercury (1958–1963)
Shortly after the Space Race began, an early objective was to get a person into Earth orbit as soon as possible, therefore the simplest spacecraft that could be launched by existing rockets was favored. The US Air Force's Man in Space Soonest program considered many crewed spacecraft designs, ranging from rocket planes like the X-15, to small ballistic space capsules.[32] By 1958, the space plane concepts were eliminated in favor of the ballistic capsule.[33]
When NASA was created that same year, the Air Force program was transferred to it and renamed Project Mercury. The first seven astronauts were selected among candidates from the Navy, Air Force and Marine test pilot programs. On May 5, 1961, astronaut Alan Shepard became the first American in space aboard Freedom 7, launched by a Redstone booster on a 15-minute ballistic (suborbital) flight.[34] John Glenn became the first American to be launched into orbit, by an Atlas launch vehicle on February 20, 1962, aboard Friendship 7.[35] Glenn completed three orbits, after which three more orbital flights were made, culminating in L. Gordon Cooper's 22-orbit flight Faith 7, May 15–16, 1963.[36] Katherine Johnson, Mary Jackson, and Dorothy Vaughan were three of the human computers doing calculations on trajectories during the Space Race.[37][38][39] Johnson was well known for doing trajectory calculations for John Glenn's mission in 1962, where she was running the same equations by hand that were being run on the computer.[37]
The Soviet Union (USSR) competed with its own single-pilot spacecraft, Vostok. They sent the first man in space, by launching cosmonaut Yuri Gagarin into a single Earth orbit aboard Vostok 1 in April 1961, one month before Shepard's flight.[40] In August 1962, they achieved an almost four-day record flight with Andriyan Nikolayev aboard Vostok 3, and also conducted a concurrent Vostok 4 mission carrying Pavel Popovich.
Project Gemini (1961–1966)
Based on studies to grow the Mercury spacecraft capabilities to long-duration flights, developing space rendezvous techniques, and precision Earth landing, Project Gemini was started as a two-man program in 1962 to overcome the Soviets' lead and to support the Apollo crewed lunar landing program, adding extravehicular activity (EVA) and rendezvous and docking to its objectives. The first crewed Gemini flight, Gemini 3, was flown by Gus Grissom and John Young on March 23, 1965.[41] Nine missions followed in 1965 and 1966, demonstrating an endurance mission of nearly fourteen days, rendezvous, docking, and practical EVA, and gathering medical data on the effects of weightlessness on humans.[42][43]
Under the direction of Soviet Premier Nikita Khrushchev, the USSR competed with Gemini by converting their Vostok spacecraft into a two- or three-man Voskhod. They succeeded in launching two crewed flights before Gemini's first flight, achieving a three-cosmonaut flight in 1964 and the first EVA in 1965. After this, the program was canceled, and Gemini caught up while spacecraft designer Sergei Korolev developed the Soyuz spacecraft, their answer to Apollo.
Apollo program (1961–1972)
NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA). The new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science.[7][8][9] Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, and later 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 also responsible for the Launch Services Program which provides oversight of launch operations and countdown management for uncrewed NASA launches.
NASA science is focused on better understanding Earth through the Earth Observing System;[10] advancing heliophysics through the efforts of the Science Mission Directorate's Heliophysics Research Program;[11] exploring bodies throughout the Solar System with advanced robotic spacecraft missions such as New Horizons;[12] and researching astrophysics topics, such as the Big Bang, through the Great Observatories and associated programs
From 1946, the National Advisory Committee for Aeronautics (NACA) had been experimenting with rocket planes such as the supersonic Bell X-1.[14] In the early 1950s, there was a challenge to launch an artificial satellite for the International Geophysical Year (1957–58), resulting in the American Project Vanguard among others. After the Soviet launch of the world's first artificial satellite (Sputnik 1) 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 (known as the "Sputnik crisis"), urged immediate and swift action; President Dwight D. Eisenhower and his advisers counseled more deliberate measures. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever.[9] 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 [Sputnik] 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.[15]
While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency (ARPA) was created in February 1958 to develop space technology for military application.[16]
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; its 8,000 employees, an annual budget of US$100 million, three major research laboratories (Langley Aeronautical Laboratory, Ames Aeronautical Laboratory, and Lewis Flight Propulsion Laboratory) and two small test facilities.[17] A NASA seal was approved by President Eisenhower in 1959.[18] 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, who was now working for the Army Ballistic Missile Agency (ABMA), which in turn incorporated the technology of American scientist Robert Goddard's earlier works.[19] Earlier research efforts within the US Air Force[17] and many of ARPA's early space programs were also transferred to NASA.[20] In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology.[17]
Leadership
The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, and reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee usually is associated with the President's political party (Democratic or Republican), and a new administrator is usually 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.[21]
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.[22]
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.[23]
The second administrator, James E. Webb (1961–1968), 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 landing goal by the end of the 1960s, Webb directed major management restructuring and facility expansion, establishing the Houston Manned Spacecraft (Johnson) Center and the Florida Launch Operations (Kennedy) Center. Capitalizing on Kennedy's legacy, President Lyndon Johnson kept continuity with the Apollo program by keeping Webb on when he succeeded Kennedy in November 1963. But Webb resigned in October 1968 before Apollo achieved its goal, and Republican President Richard M. Nixon replaced Webb with Republican Thomas O. Paine.
James Fletcher was responsible for early planning of the Space Shuttle program during his first term as administrator under President Nixon. He was appointed for a second term as administrator from May 1986 through April 1989 by President Ronald Reagan to help the agency recover from the Space Shuttle Challenger disaster.
Former astronaut Charles Bolden served as NASA's twelfth administrator from July 2009 to January 20, 2017.[24] Bolden is one of three former astronauts who became NASA administrators, along with Richard H. Truly (served 1989–1992) and Frederick D. Gregory (acting, 2005).
The agency's administration is located at NASA Headquarters in Washington, DC and provides overall guidance and direction.[25] Except under exceptional circumstances, NASA civil service employees are required to be citizens of the United States.[26]
Space flight programs
NASA has conducted many crewed and uncrewed spaceflight programs throughout its history. Uncrewed programs launched the first American artificial satellites into Earth orbit for scientific and communications purposes, and sent scientific probes to explore the planets of the solar system, starting with Venus and Mars, and including "grand tours" of the outer planets. Crewed programs sent the first Americans into low Earth orbit (LEO), won the Space Race with the Soviet Union by landing twelve men on the Moon from 1969 to 1972 in the Apollo program, developed a semi-reusable LEO Space Shuttle, and developed LEO space station capability by itself and with the cooperation of several other nations including post-Soviet Russia. Some missions include both crewed and uncrewed aspects, such as the Galileo probe, which was deployed by astronauts in Earth orbit before being sent uncrewed to Jupiter.
Crewed programs
The experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for crewed spaceflight. This was followed by a one-man space capsule program, and in turn by a two-man capsule program. Reacting to loss of national prestige and security fears caused by early leads in space exploration by the Soviet Union, in 1961 President John F. Kennedy proposed the ambitious goal "of landing a man on the Moon by the end of [the 1960s], and returning him safely to the Earth." This goal was met in 1969 by the Apollo program, and NASA planned even more ambitious activities leading to a human mission to Mars. However, reduction of the perceived threat and changing political priorities almost immediately caused the termination of most of these plans. NASA turned its attention to an Apollo-derived temporary space laboratory, and a semi-reusable Earth orbital shuttle. In the 1990s, funding was approved for NASA to develop a permanent Earth orbital space station in cooperation with the international community, which now included the former rival, post-Soviet Russia. To date, NASA has launched a total of 166 crewed space missions on rockets, and thirteen X-15 rocket flights above the USAF definition of spaceflight altitude, 260,000 feet (80 km).[28]
X-15 rocket plane (1959–1968)
The North American X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force and Navy. The design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems.[29] Requests for proposal were issued on December 30, 1954, for the airframe, and February 4, 1955, for the rocket engine. The airframe contract was awarded to North American Aviation in November 1955, and the XLR30 engine contract was awarded to Reaction Motors in 1956, and three planes were built. The X-15 was drop-launched from the wing of one of two NASA Boeing B-52 Stratofortresses, NB52A tail number 52-003, and NB52B, tail number 52-008 (known as the Balls 8). Release took place at an altitude of about 45,000 feet (14 km) and a speed of about 500 miles per hour (805 km/h).
Twelve pilots were selected for the program from the Air Force, Navy, and NACA (later NASA). A total of 199 flights were made between 1959 and 1968, resulting in the official world record for the highest speed ever reached by a crewed powered aircraft (current as of 2014), and a maximum speed of Mach 6.72, 4,519 miles per hour (7,273 km/h).[30] The altitude record for X-15 was 354,200 feet (107.96 km).[31] Eight of the pilots were awarded Air Force astronaut wings for flying above 260,000 feet (80 km), and two flights by Joseph A. Walker exceeded 100 kilometers (330,000 ft), qualifying as spaceflight according to the International Aeronautical Federation. The X-15 program employed mechanical techniques used in the later crewed spaceflight programs, including reaction control system jets for controlling the orientation of a spacecraft, space suits, and horizon definition for navigation.[31] The reentry and landing data collected were valuable to NASA for designing the Space Shuttle.[29]
Project Mercury (1958–1963)
Shortly after the Space Race began, an early objective was to get a person into Earth orbit as soon as possible, therefore the simplest spacecraft that could be launched by existing rockets was favored. The US Air Force's Man in Space Soonest program considered many crewed spacecraft designs, ranging from rocket planes like the X-15, to small ballistic space capsules.[32] By 1958, the space plane concepts were eliminated in favor of the ballistic capsule.[33]
When NASA was created that same year, the Air Force program was transferred to it and renamed Project Mercury. The first seven astronauts were selected among candidates from the Navy, Air Force and Marine test pilot programs. On May 5, 1961, astronaut Alan Shepard became the first American in space aboard Freedom 7, launched by a Redstone booster on a 15-minute ballistic (suborbital) flight.[34] John Glenn became the first American to be launched into orbit, by an Atlas launch vehicle on February 20, 1962, aboard Friendship 7.[35] Glenn completed three orbits, after which three more orbital flights were made, culminating in L. Gordon Cooper's 22-orbit flight Faith 7, May 15–16, 1963.[36] Katherine Johnson, Mary Jackson, and Dorothy Vaughan were three of the human computers doing calculations on trajectories during the Space Race.[37][38][39] Johnson was well known for doing trajectory calculations for John Glenn's mission in 1962, where she was running the same equations by hand that were being run on the computer.[37]
The Soviet Union (USSR) competed with its own single-pilot spacecraft, Vostok. They sent the first man in space, by launching cosmonaut Yuri Gagarin into a single Earth orbit aboard Vostok 1 in April 1961, one month before Shepard's flight.[40] In August 1962, they achieved an almost four-day record flight with Andriyan Nikolayev aboard Vostok 3, and also conducted a concurrent Vostok 4 mission carrying Pavel Popovich.
Project Gemini (1961–1966)
Based on studies to grow the Mercury spacecraft capabilities to long-duration flights, developing space rendezvous techniques, and precision Earth landing, Project Gemini was started as a two-man program in 1962 to overcome the Soviets' lead and to support the Apollo crewed lunar landing program, adding extravehicular activity (EVA) and rendezvous and docking to its objectives. The first crewed Gemini flight, Gemini 3, was flown by Gus Grissom and John Young on March 23, 1965.[41] Nine missions followed in 1965 and 1966, demonstrating an endurance mission of nearly fourteen days, rendezvous, docking, and practical EVA, and gathering medical data on the effects of weightlessness on humans.[42][43]
Under the direction of Soviet Premier Nikita Khrushchev, the USSR competed with Gemini by converting their Vostok spacecraft into a two- or three-man Voskhod. They succeeded in launching two crewed flights before Gemini's first flight, achieving a three-cosmonaut flight in 1964 and the first EVA in 1965. After this, the program was canceled, and Gemini caught up while spacecraft designer Sergei Korolev developed the Soyuz spacecraft, their answer to Apollo.
Apollo program (1961–1972)
ليست هناك تعليقات:
إرسال تعليق