Chapter 1 - The origins of NASA
The National Advisory Comitee for Aeronautics was founded in 1915. Although it were the American Wright brothers, who made the first controlled flight in an airplane, the United States soon lagged behind the Eurpoeans in aviation techniques. Because of World War I, the Europeans forced the development of new aircrafts. As a consequence, scientists within the United States demanded a national organization, which would help the States to keep pace with the rapid developments in aeronautics - the NACA.
For fiscal 1915, the fledgling organization received a budget of $5000, an annual appropriation that remained constant for the next five years. This was not much even by standards of that time, but it must be remembered that this was an advisory committee only, "to supervise and direct the scientific study of the problems of flight, with a view to their practical solutions."
Once the NACA isolated a problem, its study and solution was generally done by a government agency or university laboratory. The main committee of 12 members met semiannually in Washington. An Executive Committee of seven members, chosen from the main committee living in the Washington area, supervised the NACA's activities and kept track of aeronautical problems to be considered for action.
The first NACA research center was opened at Langley in Hampton, Virginia. In a wartime environment, the NACA was soon busy. It evaluated aeronautical queries from the Army, conducted experiments and ran engine tests. From the beginning the NACA was not a military organization, however it's research work while World War I focused on military affairs and the Langley Memorial Aeronautical Laboratory was built on a US Army Base. Soon a small airfield and a wind tunnel for aerodynamics testing were set up. Although after the war, the Army transferred its research facilities to Dayton, Ohio, military influence at Langley remained high. In 1920 the NACA owned a airfield, a wind tunnel, a small dynamometer lab, a warehouse and a administration building. With a total staff of 11 people there was plenty room to grow. The Universities over the country began to offer education in aeronautics theory and engineering. Young engineers joined the NACA and the Langley's staff went up to 100 in 1925. During the '20s and '30s, NACA research turned the art of aeronautics into a disciplined engineering profession. Military and private airplane designs greatly benefited from NACA's research, which led to improved wing shapes and engines and retractable landing gears. With more and more commercial airlines in business, the research also concentrated on maximum passenger safety and comfort.
After a while, a new field of aeronautical research emerged: Rocketry. Inspired by Jules Verne and others, scientists around the world became increasingly interested in Rocketry. NACA conducted some rocket experiments, which not only led to the use of rockets by the United States armed services in World War II, but later also led to the development of jet propulsion engines, which replaced the older propeller engines. The NACA - born in response to European progress in aeronautics - benefited through the employment of Europeans, and profited from a continuous interaction with the European community.
Hitler's Germany stopped to share its research results in expectation of the second World War. The "Verein für Raumschiffahrt", which employed the famous Wernher von Braun, was very successful in developing rockets and jet propulsion and therefore the Germans were the only nation, which used ground to ground rockets during the war (The V-2 rocket, Vengance-2). They also put the only WWII jetfighter plane in the skies, the Messerschmitt Me-262 - in 1945, shortly before Germanys surrender and therefore too late to play an active role in the european air war.
For the NACA, the war was a pretty good reason to let the government multiply their resources and fundings. For example: the NACA counted 426 staff at Langley in 1938. After the war, in 1945 total personnel at Langley exceeded 3000 people. In 1941 a second Laboratory, the Ames Aeronautical Laboratory in California, followed in 1942 by the Aircraft Engine Research Laboratory in Ohio were established. NACA's success in producing fast and manoeuvrable planes gave the US Air Force the deciding edge in aerial combat during WWII.
In October 1942, America's first jet plane, took to the air over a remote area of the California desert. There were no official NACA representatives present. The NACA, in fact, did not even know the aircraft existed, and the engine was based entirely on a top secret British design. After the war, the failure of the United States to develop jet engines and supersonic designs was generally blamed on the NACA. Critics argued that the NACA, as America's
premier aeronautical establishment (one which presumably led the world in successful aviation technology) had somehow allowed leadership to slip to the British and the Germans during the late 1930s and during World War II. The US secret service initiated the "Operation Paperclip", a high-level government plan to scoop up leading German scientists and engineers during the closing months of World War II.
Following the war, the NACA, with German scientists know-how, increasingly focused on jet propulsion and the attainment of even higher altitudes and speeds. In 1947 the NACA X-1 (eXperimental jet-1) was the first plane to brake the sound barrier and go supersonic (Mach 1 equals the speed of sound. The designation is named after the Austrian physicist, Ernst Mach).
Helicopters, introduced into limited combat service at the end of World War II, entered both military and civilian service in the postwar era. The value of helicopters in medical evacuation was demonstrated in Korea, and a variety of helicopter operations proliferated in the late 1950s. The NACA flight-tested new designs to help define handling qualities. Using wind tunnel experience, researchers also developed a series of special helicopter airfoil sections, and a rotor test tower aided research in many other areas.
All of this postwar aeronautical activity received respectful and enthusiastic attention from press and public. Although the phenomenon of flight continued to enjoy extensive press coverage, events in the late 1950s suddenly caused aviation to share the limelight with space flight.
Among the legacies of World War II was a glittering array of new technologies spawned by the massive military effort. Atomic energy, radar, radio telemetry, the computer, the large rocket, and the jet engine seemed destined to shape the world's destiny in the next three decades and heavily influence the rest of the century. The world's political order had been drastically altered by the war. Much of Europe and Asia were in ashes. On opposite sides of the world stood the United States and the Soviet Union, newly made into superpowers. It soon became apparent that they would test each other's mettle many times before a balance of power stabilized. And each nation moved quickly to exploit the new technologies.
The atomic bomb was the most obvious and most immediately threatening technological change from World War II. Both superpowers sought the best strategic systems that could deliver the bomb across the intercontinental distances that separated them. Jet-powered bombers were an obvious extension of the wartime and both nations began putting them
into service. The intercontinental rocket held great theoretical promise, but seemed much further down the technological road. Atomic bombs were bulky and heavy. A rocket to lift such a payload would be enormous in size and expense. The Soviet Union doggedly went ahead with attempts to build such rockets. The US Army imported Wernher von Braun and the German engineers who had created the wartime V-2 rockets to help to develop the Atlas intercontinental ballistic missile, a project that had been dormant for four years. Fiscal 1953 saw the Department of Defense for the first time spend more than $1 million on missile research. By the mid-1950s NACA had modern research facilities that had cost a total of $300 million, and a staff totaling 7200.
Against the background of the "Cold War" between the United States and the USSR and the national priority given to military rocketry, the NACA's sophisticated facilities inevitably became involved. With each passing year it was enlarging its missile research in proportion to the old mission of aerodynamic research.
As part of the US participation in the forthcoming International Geophysical Year, it was proposed to launch a small satellite into orbit around the Earth. When USSR announced, that they also would launch a satellite into orbit, the space race was extending beyond boosters and payloads to issues of national prestige.
In 1957, when the "beep, beep" signal from Sputnik 1 was heard around the world the Soviet Union had orbited the world's first manmade satellite.
When the US Army finally launched their Explorer 1 satellite, the payload weighed only 2 pounds against the 1100 pounds of Sputnik 2. An experiment aboard the satellite reported mysterious saturation of its radiation counters at 594 miles altitude. Professor James A. van Allen, the scientist who had built the experiment, thought this suggested the existence of a dense belt of radiation around the Earth at that altitude - the van Allen radiation belts.
The US government sought for an agency, which would help the United States to catch up with the fast advancing USSR space program. Either the Department of Defense or the NACA should begin with the development of a national space program.
The NACA research team had come up with a solid, longterm, scientifically based proposal for a blend of aeronautic and space research. Its concept for manned spaceflight, for example, envisioned a ballistic spacecraft with a blunt reentry shape, backed by a world-encircling tracking system, and equipped with dual automatic and manual controls that would enable the astronaut gradually to take over more and more of the flying of his spacecraft. Also NACA offered reassuring experience of long, close working relationships with the military services in solving their research problems, while at the same time translating the research into civil applications. But NACA's greatest political asset was its peaceful, research-oriented image. President Eisenhower and Senator Johnson and others in Congress were united in wanting above all to avoid projecting cold war tensions into the new arena of outer space.
Chapter 2 - The foundation of the NASA
On 29 July 1958 President Eisenhower signed the National Aeronautics and Space Act of 1958. The act established a broad charter for civilian aeronautical and space research with unique requirements for dissemination of information, absorbed the existing NACA into the new organization as its nucleus, and empowered broad transfers from other government programs. The National Aeronautics and Space Administration came into being on 1 October 1958. All this made for a very busy spring and summer for the people in the small NACA Headquarters in Washington. Once the general outlines of the new organization were clear, both a space program and a new organization had to be charted. The NACA's assistant director for aerodynamic research, headed a committee to plan the new organization.
Talks with the Advanced Research Projects Agency identified the military space programs that were space science-oriented and were obvious transfers to the new agency. Plans were formulated for building a new center for space science research, satellite development, flight operations, and tracking: The Goddard Space Flight Center was dedicated in March 1961. The 8000 people, three laboratories (now renamed research centers) and two stations, with a total facilities value of $300 million and an annual budget of $100 million were transferred intact to NASA. There followed an intense two-year period of organization, build up, fill in, planning, and general catch up. Only one week after NASA was formed, Congress gave the go ahead to Project Mercury, America's first manned spaceflight program. The Space Task Group was established at Langley to get the job done. The new programs brought into the organization were slowly integrated into the NACA nucleus. Many spaceminded specialists were drawn into NASA, attracted by the exciting new vistas. Long-range planning was accelerated. The first NASA 10-year plan was presented to Congress in February 1960. It called for an expanding program on a broad front: manned spaceflight (first orbital, then circumlunar), scientific satellites to measure radiation and other features of the near-space environment, lunar probes to measure the lunar space environment and to photograph the Moon, planetary probes to measure and to photograph Mars and Venus, weather satellites to improve our knowledge of Earth's broad weather patterns, continued aeronautical research, and development of larger launch vehicles for lifting heavier payloads. The cost of the program was expected to vary between $1 billion and $1.5 billion per year over the 10-year period.
High speed airplane research continued and led to the NASA's X-15, which attained a speed of Mach 6,7 which is 7,270 km/hr, the fastest speed ever reached by a jet. The X-15 contributed heavily to research in spaceflight as well as to high-speed aircraft research. Using the powerful X-15 engines, the first vertical takeoff and landing plane was developed.
A 4000-person Development Operations Division, headed by Wernher von Braun, was transferred from the Army to NASA along with the big Saturn booster project.
Chapter 3 - The race for the Moon
Against the background of the "Cold War", US President J.F. Kennedy announced in 1961, for the obvious reason of gaining prestige, that the United States would dedicate this decade to bringing a man up to the moon and returning him to Earth. The job was handed over to NASA, the United States' civilian Agency for Space Exploration.
The NASAs conquest of the moon was divided in three programs: the Mercury Program and the Gemini Program, whichs purpose it was to test the limits of NASAs space vehicles and to train astronauts for the final Apollo Program.
The Mercury program was the earliest NASA project to put an astronaut into space. It utilized one-person, bell-shaped capsules that were boosted into orbits 161 to 283 km above the Earth. The capsules reentered the atmosphere ballistically, and parachutes were deployed on the final descent to ocean splashdown. The capsules were then recovered by U.S. naval vessels and helicopters. The project successfully flew two suborbital and four orbital manned missions.
The project cost slightly more than $400 million and involved the technical skills of more than 2 million men and women in the research, development, and testing of the spacecraft, its launch vehicles, and a worldwide tracking and communications network.
Although manned spaceflight had been studied since the late 1940s, serious development of a manned satellite was not considered by Congress until after the Soviet Union launched Sputniks 1 and 2 in October and November 1957. In March 1958, the NACE proposed a wingless, manned satellite that could follow a ballistic path to reenter the atmosphere without exposing the crew to excessively high temperatures or dangerous acceleration. The chief points of this proposal were incorporated into the Mercury program.
The size and weight of the Mercury spacecraft were dictated by the lifting capability of the intercontinental ballistic missiles of the US Army. The capsule was designed to weigh less than 1,350 kg, because the lifting capacities of these missiles was limited.
The astronaut reclined on a contour couch designed to provide protection from accelerations of as much as 20 gravities.
The attitude, or position, of the capsule was controlled by an array of 18 hydrogen-peroxide gas thrusters. These could pitch the spacecraft up or down, yaw it left or right, or roll it. The pilot could fire them by means of a hand controller or leave attitude control to an autopilot.
Following the launch, the most critical part of the flight was the firing of the braking rockets. The pilot was required to put the capsule in a precise attitude for retrofire in order to land in the sea near the recovery ships.
During 1960-61, the Mercury capsule was launched by a Redstone missile on a series of suborbital flights that tested the integrity of its structure and the effectiveness of the launch escape tower. The tower contained a powerful rocket that would pull the spacecraft away from the launch vehicle in the event the launcher failed during liftoff. It was activated only once, when the Redstone launcher failed in November 1960. The tower rocket pulled the spacecraft high above the Atlantic Ocean so that it could parachute into the water.
One of the first Mercury flights took a 17-kg chimpanzee named Ham on a suborbital flight, from which he was recovered unharmed.
During other manned suborbital flights the control systems of the spacecraft were tested.
Following a series of Mercury unmanned orbital test flights Lt. Col. John H. GLENN, Jr., flew a three-orbit (4 hr 55 min) mission (1962) in the spacecraft he named Friendship 7. As the first American to fly in orbit, Glenn received a hero's welcome on the same scale as that accorded Charles A. Lindbergh after his New York-Paris flight in 1927.
Project Mercury ended with a 22-orbit (34 hr 20 min) flight in 1963.
Four years and 10 months after NASA was created, the first American manned space program had been completed.
The Gemini program was a series of piloted spaceflights in the mid-1960s. The series was authorized by Congress in 1961 as an intermediate step, between the Mercury Program and the Apollo Program, in the U.S. effort to land on the Moon. It was called Gemini, which means 'twins' in Latin, because each piloted flight carried two astronauts into orbit.
The earlier Mercury program had demonstrated that a trained astronaut could fly in orbit for up to 34 hours. The NASA next had to determine whether trained crew members could endure the weightlessness of orbital freefall long enough to survive a journey to the Moon and back. This was one important objective of the Gemini program. Others were to develop rendezvous and docking techniques needed for the lunar mission and to train personnel in their use.
A highly maneuverable spacecraft was required, with an elaborate life-support system that could maintain a crew for up to 14 days. A NASA team designed a two-person spacecraft, that fulfilled all the needs it was created for. Within five years, the program had achieved all of its objectives. Its total cost was $1,283,400,000, including $797,400,000 for the spacecraft, $409,800,000 for launch vehicles, and $76,200,000 for support facilities. The flight series used the $79,900,000 global tracking and communications network established in Project Mercury.
The first piloted Gemini mission, Gemini 3, was flown in March 1965. Five days earlier, the Soviet cosmonaut Aleksei Leonov had spent ten minutes outside Vokshod 2 in the first demonstration of extravehicular activity (EVA) during orbital flight. This feat was duplicated in June on the four-day, 62-orbit flight of Gemini 4. The NASA astronaut remained outside for 20 minutes in a 14-kg space suit designed for EVA.
The program also attempted to achieve rendezvous and docking with another vehicle in orbit. The original plans called for a Gemini spacecraft to dock with an AGENA rocket. The first attempt was canceled in October 1965, when the Agena blew up after having been launched by an Atlas missile. After an unsuccessful effort during which the launch rocket sputtered but did not lift off, Gemini 6 was sent into orbit in December 1965.
Meanwhile, the Gemini 7 spacecraft had been launched and it was decided that Gemini 7 would serve as the vehicle with which Gemini 6 would rendezvous. Gemini 6 was piloted within one foot of Gemini 7 on December 15. This was the first successful rendezvous in space. The crew of Gemini 7 went on to set a new endurance record in space: they made a controlled landing in the Atlantic on December 18, 1965, after 330 hours and 35 minutes in orbit. Their mission proved that trained men could endure a round trip to the Moon. On its 220 orbits of the Earth, Gemini 7 had flown 20 times the distance to the Moon.
Rendezvous and docking with an Agena target rocket was achieved on March 16, 1966, during the mission of Gemini 8, by NASA astronaut Neil A. Armstong. The mission was abruptly terminated, however, when a malfunction in the Gemini "Orbital Attitude and Maneuvering System" thrusters forced the crew to undock and make an emergency landing in the western Pacific Ocean.
Overheating and face-plate fogging, which had interfered with early EVA (extravehicular activity) efforts, were overcome by Air Force Maj. Edwin E. "Buzz" Aldrin, Jr., on the flight of Gemini 12. After he and Lovell docked with an Agena rocket, Aldrin succeeded in performing 2 hours and 9 minutes of continuous work outside the spacecraft. The splashdown of Gemini 12 on Nov. 15, 1966, ended the program.
The Apollo program was the successful conclusion of the NASAs effort to achieve, within the decade, the goal of landing a man on the Moon and returning him safely to Earth. It followed the Gemini manned-flight program conducted in 1966-67 to develop the necessary techniques of orbiting, docking, and extravehicular activity (EVA). The main elements of the Apollo project were the three-man Apollo spacecraft; the two-man Lunar Excursion Module or Lunar Module and the Saturn family of rockets. These units made up the first manned, interplanetary transportation system. Using this system, astronauts landed on the Moon, where they explored and collected samples at six sites on the near side between July 1969 and the end of December 1972. The total cost of developing and operating the Apollo-Saturn transportation system in the lunar program was $25 billion.
Between October 1968, when the Apollo-Saturn transportation system underwent its first full space test, and July 1975, when it was used for the last time, the NASA launched 15 manned Apollo-Saturn flights. During the testing period three fatalities occurred on the launchpad at the Kennedy Space Center, Florida, but none in actual flight.
Launched July 16, 1969, Apollo 11 made the first manned lunar landing on July 20. As Lt. Col. Michael Collins orbited the Moon in the mother ship Columbia, Neil Armstrong and Col. Edwin E. Aldrin, Jr., touched down in a region called "Sea of Tranquility", in the Lunar Module Eagle with the historic report: "Houston, Tranquility Base here. The Eagle has landed." Armstrong was the first out. Dropping the last meter from the ladder, he said: "That's one small step for man, one giant leap for mankind" (NASA later reported that the word "a" had been lost in transmission).
On the Moon, Armstrong and Aldrin erected the American flag and set up scientific instruments, including a laser beam reflector, a seismometer that later transmitted evidence of a moonquake, and a sheet of aluminum foil to trap Solar Wind particles. The astronauts took soil and rock photographs and collected 24.4 kg of rock and dirt samples. Armstrong, the first out and the last back into the Lunar Module, spent 2 hours and 13 minutes outside. After Armstrong and Aldrin returned to Columbia in the ascent stage of the Eagle, Collins fired the Apollo main engine and lifted the vessel out of lunar orbit for the return to Earth. The ascent stage of the Eagle was left in lunar orbit. The crew landed in the Pacific Ocean on July 24, 1969, reaching the NASAs goal of visiting the moon within the 60's.
After the successful moon landing of Apollo 12, where 33.9kg of rocks were picked up and returned to Earth, the Apollo 13 mission failed.
Two days after Apollo 13 was launched in 1970, an oxygen tank exploded in the Service Module and crippled the vessel's power and life-support systems so badly that a planned landing in the Fra Mauro formation of the Moon was canceled. The crew used the descent engine of the Lunar Module Aquarius to accelerate the crippled spacecraft around the Moon and back to Earth. Using Aquarius as a lifeboat, they returned to the vicinity of Earth, entered the Command Module, and landed it safely on April 17. Investigation showed that a thermostatically controlled switch had failed and allowed the oxygen tank to overheat.
The Apollo Program, which started during a time of intense competition between the United States and the USSR, ended in a demonstration of detente in space: a joint orbital flight of the Apollo and Soyuz spaceships, known as the Apollo-Soyuz Test Project. Technically, the joint mission in low Earth orbit demonstrated intership crew transfer and space rescue. The total cost to NASA of the Apollo-Soyuz Test Project was $250 million.
The vessels docked over a spot in the Atlantic Ocean some 1,030 km west of Portugal on July 17, 1972. During the next two days, the crews made four transfers between the two ships and completed five planned experiments. The nine-day mission was the last one of the Apollo program.
Eleven missions of the Apollo Program were missions in the lunar landing program, including two test flights in low Earth orbit, two test flights in lunar orbit, six landings, and one circumlunar flight, during which the planned landing was aborted (Apollo 13).
The question, why the U.S. put a man on the moon before the USSR did, is easy to answer: The USSR had powerful boosters at their disposal and therefore didn't need to minimize the weight of their spacecrafts. The NASA benefited from the low weight of their spacecrafts, which made it possible to build the Lunar Module, which could land and then take off from the Moon's surface.
Chapter 4 - The Shuttle Program
The NASAs Space Shuttle is a reusable spacecraft designed to be launched into orbit by rockets and then to return to the Earth's surface by gliding down and landing on a runway. The Shuttle was selected in the early 1970s as the principal space launcher and carrier vehicle to be developed by the NASA. It was planned as a replacement for the expensive, expendable booster rockets used since the late 1950s for launching major commercial and governmental satellites. Together with launch facilities, mission control and supporting centers, and a tracking and data-relay satellite system, it would complete NASA's new Space Transportation System.
After various delays, the program got under way in the early 1980s. Despite a number of problems, the craft demonstrated its versatility in a series of missions until, in January 1986, a fatal Shuttle disaster during launch forced a long delay until the program was resumed late in 1988.
Ultimele referate adaugate
- Opere romantice - autori si opere reprezentative Gioacchino Rossini, Giuseppe Verdi, Richard Wagner
- Mihai beniuc - „poezii"
- Mihai eminescu - student la berlin
- Mircea Eliade - Mioara Nazdravana (mioriţa)
- Chirita in provintie de Vasile Alecsandri -expunerea subiectului
- Dragoste de viata de Jack London
|Ion Luca Caragiale
- Triumful talentului… (reproducere) de Ion Luca Caragiale
- Fantasticul in proza lui Mircea Eliade - La tiganci
- „Personalitate creatoare” si „figura a spiritului creator” eminescian