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рефераты скачатьThe magnificent seven

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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