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Artificial earth satellites


Artificial earth satellites
The launch of the first satellite in the Soviet Union began to think back in those days, when there were working on a ballistic missile R-7. In 1956, a group of scientists has been formed headed by Academician Mstislav Keldysh, which was tasked to develop a program of scientific experiments for the first artificial Earth satellite. After a preliminary review of all on-board systems, which should have been provided with the satellite, it appeared that nothing is impossible to meet the weight of less than 1,250 kg (weight of one shell was 250 kg, the power supply system - 450 kg; in addition, a lot of weight had a massive antenna ). There was then a rocket could not tell the first cosmic velocity (about 8 km / s) such a heavy machine. Then in late 1956, one of the employees of the Queen, Michael Tikhonravov, proposed the project more simple and easy satellite with a mass of about 80 kg. In June 1957, the final drawings were ready to build the satellite, and in late August, began his trial.

To launch the satellite on the orbit CB Queen on the basis of R-7 has developed a special two-stage missile with a total weight of 267 tonnes, consisting of four side rocket units of RD-107 and one central block of RD-108. All engines are included at the start of the work at the same time. After 120 seconds after the start of the side frame is discarded (the second stage by this time reached a height of 50 km and had a rate of 2, 3 km / s). Central Unit continued to work another 180 seconds. At an altitude of 200 km of the central unit switches off, after which the satellite is separated from it by a rod spring, the protective heat shield is dropped and began to coast. Successful missile launch took place October 4, 1957. The day was opened by the beginning of a new era of space in Earth's history.

The first satellite marked a key point of the art. On the one hand, it symbolized the end of a complex stage of development of ballistic missiles, and on the other - was the germ from which grew all the later space technology.

The satellite was shaped like a sphere with a diameter of 580 mm. Weight it amounted 83, 6 kg. On the outer surface of the ball antenna transmitters installed in four rods. The length of two of them was 2 to 4 m, and the rest - 2 m. The rods were connected to the antenna insulators fixed to the satellite body via hinges, enabling them to be rotated through a certain angle. All equipment with energy sources placed in an airtight aluminum alloy. Before starting the satellite was filled with nitrogen gas. To maintain a stable internal temperature nitrogen forced circulation system has been developed. To connect two radio antennas, which emit each in its frequency is the same signal, like the telegraph. Inside the case were placed delicate sensors which changed several transmission signal (frequency of the transmitted pulses and their duration) with varying temperature and pressure inside the satellite. Power transmitters was sufficient for reliable reception of signals by all radio amateurs in the world. The power supply was capable of operating all the equipment within three weeks.

Already 3 November 1957 was launched into space a second Soviet satellite weighing 508 kg 3. It represents the last stage of the carrier rocket, on which several containers placed scientific instrumentation, and cut off the dog Laika.

In front of the satellite is a spectrograph to study the Sun, the spherical container with radio transmitters and pressurized cabin with a dog. In the case of a rocket placed two instruments for studying cosmic rays. By design, spherical container was similar to the first artificial satellite. Here, apart from the transmitter is a power supply and a variety of sensors. Hermetic cabin, which was placed Laika, took the form of a cylinder. On its removable bottom was constructed of plexiglass porthole. The cabin, made of aluminum alloys, there were a device for feeding, air conditioning, recycling plants and thermal control system. Regeneration is done by chemical elements, which absorb carbon dioxide and release oxygen. Special sensors recorded pulse, blood pressure and breathing dogs. All this, as well as information on the temperature and pressure in the cabin was reported to the Earth with the help of special equipment, which includes hours of programming device. The observation program was designed for seven days, but after that the satellite mission lasted for many days. Only April 14, 1958, made about 2370 rpm, the second satellite burned up in the atmosphere.

At this time in space, flew for the third satellite - American "Explorer 1". The reason why the American satellite in space proved not the first or even the second, not only has the technical implications. In 1955, when the US government decided to prepare for the launch of the satellite, we were offered three competing programs, for each of which stood his powerful military department: Army, Air Force and Navy. The preference was eventually given to the Navy project "Avangard", which received the privileged funding. Meanwhile the army at that time already has the best American rocket "Redstone" created under Brown's leadership. (Brown, at the time headed the Redstone Arsenal, where the missile was designed.) In September 1956, the Army successfully launched a four-ballistic missiles "Jupiter-C», which as the first stage was used the Brown "Redstone", and as a second , third and fourth - "Baby Sergent" solid rocket. Three of this stage of the rocket were natural, and the fourth was carrying sand in tanks for fuel. This level reached an altitude of 1094 km. Later, repeatedly tried to prove that if the fourth stage was fueled by, it could well become the first artificial satellite, and space age would have started a year earlier. But be that as it may, it does not happen. Meanwhile, the project "Avangard", which from the outset pursued the failure, scandal ended in failure: when starting December 6, 1957 a rocket "Vanguard", barely looking up from the launch pad, fell to the ground within the launch site and burned. it was decided to launch the satellite on the basis of the rocket "Redstone" After that, in order to save the prestige. The satellite "Explorer-1" was created in an emergency rush to the Jet Propulsion Laboratory of the California Technical University. 8 satellite weighed 21 kg and had hardware to 5 kg. In addition to a Geiger counter on board housed in microphone for recording meteor particles, temperature sensors, transmitters and power supplies. Starting on January 31, 1958 was successful. Sputnik in orbit worked eight weeks. Despite its miniature size, "Explorer 1" led to important observations. It was through his messages was discovered the radiation belts surrounding the Earth at an altitude of more than 1000 km.

In the same year, on May 15 the Soviet Union launched its third satellite. It was already possible to call this automated research station. 3 satellite length was 5 m, diameter - 1, 5 m, weight - 1327 kg, the equipment had to scientific 968 kg. Design and construction of the satellite have been worked out much more carefully than the first two. To automatically control the operation of all the scientific and measuring equipment in it was found a temporary e-mail software and device made entirely on the semiconductor elements.

Also onboard power source was equipped with a satellite solar battery. The voltage produced by this battery, it was more than that of the on-board battery, so the sunny side of the whole apparatus was fed from it. This third satellite operated for much longer than the first two - he was in flight 691 a day, and the last signal from it was passed April 6, 1960.

The first spacecraft notable for their individuality. Even without delving deep into their structure, one only appearance could tell at once that it is a completely different device. But cell phones, manufactured each time customized, expensive. Therefore, in the following years in the USSR, it was decided to move from the individual satellites for mass production. Thus began serial Soviet satellite "Cosmos". March 16, 1962 the first satellite of the series was launched.

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