На
Главную
ГДЗ:
Английский
язык Алгебра Геометрия Физика Химия Русский
язык Немецкий
язык
Подготовка к экзаменам (ЕГЭ) Программы и пособия Краткое содержание Онлайн учебники
Шпаргалки Рефераты Сочинения Энциклопедии Топики с переводами
Все темы:"Рефераты по Иностранные языки"
The magnificent seven.
THE MAGNIFICENT SEVEN
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.
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.
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.
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.
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.
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.
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.
1 2 3 4 5