Реферат по предмету "Английский язык"


The magnificent seven

THE MAGNIFICENT SEVEN
1. In September 1944 London was bombarded by the world's first ballistic missile, V2, "Vengeance Weapon No. 2". It did not make the slightest deflection in the course of the World War II, however gave an impetus to brainwork of American and Soviet rocketeers.
In the course of Hermes operation in 1945 American agents secretly took a group of German rocketeers away from the Soviets' occupation zone. The group was headed by Walter Dornberger, the leader of the Nazi missile project, and Werner von Braun, General Designer of A-4 missile (first name V-2). In addition, parts necessary for assembly of one hundred of missiles were taken across the Atlantic.
2. Sergei Korolyov, who was sent to Germany with the same mission, also managed to select some German specialists, documents and materials. One of such engineers was Helmut Grettrup, Braun's assistant in electronics. The last event on the "rocketry scene" in '45 was a trial launch of several V-2s, organized by General Eisenhower. Those launches were attended by the future General Designer of the Soviet rockets, Sergei Korolyov. A little after the ex-Allies cast the veil of secrecy and began to actively analyze their trophies. Mr. Braun and his companions tested A-4 missile in White) Sands, New Mexico. Korolyov did the same on Kapustin Yar rocket range in Russia. Helmut Grettrup and 150 more engineers designed G-1 rocket, based on A-4 prototype.
Mr. Korolyov and his teammates clearly saw weak spots of A-4, however Stalin's order sounded unambiguously: the rocket had to be duplicated without any modifications. On September 1947 the first Soviet analogue, R- 1, was launched in Kapustin Yar. Simultaneously, a new, improved missile was being designed, R-2. It was commissioned in 1951. Laterthe experimental rocket R-3Aand its following modification, R-5 were created. I_By the early '50s Soviet rocketeers had enough experience creating one-stage ballistic missiles. A group of German scientists headed by Mr. Grettrup also presented their project in 1947. Although the project offered quite advanced solutions, it was not approved and the Germans were soon repatriated.
3. In 1947, Mr. M.K. Tikhonravov, a Head of the group studying multistage rockets at the Research Institute of Artillery, proposed to use a bunch, or a "packet" of R-3 rockets as the first stage. This was named "packet design". During the years 1949-1950 Tikhonravov group designed a project of a two-stage packet-design rocket. Calculations proved that this rocket was able to deliver three tons to a distance of 3000 km and, what is more important, a spacecraft could be lifted to the Earth orbit. In the beginning of 1953 the Soviet Government commanded to start a project on creation of R-7, a two-stage intercontinental ballistic missile.
4. Concurrently with the creation of "the seven", a spacecraft was also being designed. By the end of 1955 the preliminary project was ready and creation of Sputnik began. According to the project, the satellite had to weigh some 1400 kg and bear 300 kg of scientific equipment. However, parameters of the supposed carrier did not allow the lift this much load. The decision was made to cut the weight of a satellite at the expense of scientific equipment.
5. As we remember, first-rate German specialists and parts of rockets were brought to the United States. In 1946 at the White Sands Range the first launch of A-4 rocket was made. The Americans started developing their rocketry program and Werner von Braun had no small share in it. He was the General Designer of a two-stage rocket named Bumper, where A-4 itself served as the first stage. On July 24,1950, Bumper was launched from a new range located on the Canaveral Cape. In the same year Research Center moved from the White Sands to the Redstone Arsenal, located in Huntsville, Alabama and Mr. Braun's team began to work on the Redstone rocket which also was a further modification of A-4.
Back in Peenemuende, Germany Werner von Braun already matured plans of orbiting a satellite for spying upon adversary. These were plans to create a two-stage powerful rocket based on A-4, which would be able to develop the first cosmic velocity with spaceborne payload. That project died adorning.
In 1948 the Secretary of Defense of the U.S. announced the intentions to orbit a shell-satellite in the nearest future, for military purpose, of course. This project required colossal expenses on both creation of a booster rocket and a spacecraft. It was just about the time when semiconductor transistor was only patented; electronics would have become miniature much later.
In 1951 members of the British Interplanetary Society issued their work titled "Minimum Satellite", where a concept of orbiting of a satellite was described at utilization of existing technologies and components. One of the problems encountered by creators of a two-stage rocket was startup of the second-stage engines in weightlessness. Liquid propellant would not flow to where it was necessary. To make a solid fuel stage, a completely new class of solid propellants had to be created. In a packet design rocket the engines of the both stages could be started up already on earth which led to some loss in hoist capacity, but added much robustness.
The Second International Geophysical Year was proclaimed since July 1957 through December 1958. Within the framework of this event the U.S. and the USSR were going to launch their first satellites. The Americans announced their intention in July 1955. The ad hoc committee chose the Vanguard project, proposed by the Naval Research Laboratory.
However, in 1955 Dwight Eisenhower, the then President of the U.S., announced about the priority of military projects. This made the civil program Vanguard a matter of secondary importance. The Martin Company (now Lockheed Martin), where Vanguard rocket was being created, obtained the order on creation of Titan ballistic missile. The most of the company's resources were retargeted to the military project.
In February 1956 the Vanguard rocket was ready. The 'Martin Company and NRL carried out a number of trial launches from December 1956 to October 1957. The launch of a satellite was scheduled to December 1957.
While the Martin Company built their Vanguard, Mr. Braun's team designed their Redstone rocket. A modified A-4 was used as the first stage, the second and third ones were packets of solid propellant accelerators. That rocket was first launched in September 1956. The carrier delivered a dummy warhead over a distance of 5300 kilometers.
6. In 1955 near Tyura-Tam station in Kazakhstan construction of a rocket range began, which later became Baikonur Spaceport. On May 15 the first "seven" started from this range. The first three launches failed. On August 21 the fourth launch was made. The rocket successfully started and several days after the debris of its head were found in prescribed region on Kamchatka Peninsula.
7. Americans realized that orbiting of the first satellite in the USSR was a matter of weeks. They even called a conference devoted to the subject. The conference was scheduled on October 4, 1957, but a few hours later the world was told the news: the USSR was the first state to launch an artificial satellite, Sputnik.
On December, 6 the Vanguard carrier exploded on a launchpad. The first American satellite, Explorer I, was orbited on January 31,1958, by a modified Redstone carrier named Jupiter C.


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