DETECTION AND HISTORY OF SATELLITE COMMUNICATIONS

 Nearly a century before the communication is created and enabled the satellite in orbit

some people have been talking about the idea of ​​using satellites like it for the benefit of man. Although initially only a fantasy in the form of fiction pouring. For example, a short story made ​​by several authors including

1. Edward Everett Hale in 1869 , The Brick Moon .
2. the king of science fiction , Jules Verne , in his novel Begum 's Millions in 1879 .
3. In 1945 , Arthur C. Clark has written the first scientific article on the theory of the use of artificial satellites as a means of telecommunication . Article he wrote was titled Extra - Terrestrial Relays . Before Clark writes Extra - Terrestrial Relays , actually there are people who also discusses the idea of ​​using a space vehicle as a means of telecommunication .
4. He is Herman Potocnik who in 1928 published his book Das Problem der des Weltraums Befahrung - der Raketen - Motor . In fact, this is the Slovenian -born man who first revealed his term through the geostationary orbit . And he described the long-distance communication that takes place between the earth with the vehicle through radio waves . But Potocnik not mention the idea of ​​the functions of the vehicle as a relay or intermediary in the process of long-distance communication . It makes not much of a person who first talked about satellite communications as a scientific idea .

Sputnik-1 on December 18, 1958 More than one year after the Soviet Union successfully launched a communications satellite launched America's first time in the world in the SCORE project. The satellite orbits the Earth in just 12 days. And with the satellite intermediaries, Eisenhower delivered a message that was widely broadcast. Due rocket technology at that time have not been able to throw a load of equipment that must be transported by a communications satellite into orbit, the satellite's position as it was followed by a giant balloon 30 feet in diameter,

name Echo-1. launched on August 12, 1960 and occupies an altitude of about 1,600 kilometers from Earth. The exterior of the balloon is coated with a thin aluminum that serves to reflect radio waves from the ground station. Its function is really a mirror reflector. Since the function only reflect radio waves using its aluminum skin, the reflected waves are received by ground stations to be very weak. Even so, the intermediary Echo-1, radio communications can be performed at a distance of up to 4,000 kilometers (connecting the U.S. east coast to California).

Telstar To overcome the weaknesses of the Echo-1 Telstar was launched on July 10, 1962 it was launched, the satellite communication has been equipped with the most advanced technology of his day. Telstar has a weight of 64 kilograms. Equipped with 3,600 solar cells that serves to create an electric current and charge the Nickel Cadmium battery on the satellite. Moreover it has no less than one thousand transistors and a tube amplifier that can strengthen the signal received from the Earth up to 10,000-fold. A few hours after the live TV broadcast of the first times in the world of an earth station in Andover managed to cross the Atlantic Ocean. So since that's when the man began to enter the era of satellite communications. And now, the use of intermediaries as a means of telecommunication satellites has become common for almost everyone.

Based on the stages of its path, the satellite experienced a six-stage development.

1. In the first stage , the satellite using a rocket thrown as far as possible in space so that the satellite could be right around the Earth in one day to one round . As we know , the Earth rotates in 24 hours on its axis for one rotation ( rotation ) . Therefore , at an altitude of about 36,000 kilometers from the Earth , the satellite communication in a practical standstill despite the truth being in orbit around the Earth . At every hour , a distance of 15 satellites degrees of the orbital path . 
2. In the second stage rocket created correction system which is set by the computer to prevent shifting of satellite orbits . In the following years of rocket correction capability and fuel utilization has been further refined so that a capable communication satellite in orbit for years . 
3. In the third stage is characterized by the development of three- axis stabilization system that makes the satellite has not changed its position and antennae always leads to Earth . Some small rocket engines work in unison to maintain the position of the satellite . Previously, the method used is made ​​satellites continuously rotating on its axis . This makes the antenna rotating movement only occasionally leads to Earth . The solution is made ​​antenna that comes with buckshot strands that do not participate rotating antenna with the satellite body . Same function as exactly as buckshot tires on the bike . 
4. In the fourth stage rocket has been created that is capable of carrying much heavier loads . If the rocket in 1962, which is only capable of transporting Telstar weighs 64 kilograms , then the rocket today should be able to throw its weight satellites already in tonnes to the geostationary orbit . 
5. In the phase 5 people have been able to make the electronic elements are much smaller than the same element in the initial generation satellites . Until the equipment can be included in a satellite can be more and more . Tool that is used to receive and send signals transponder name . If the Intelsat V satellite , which was launched in 1980 only has 12 transponders , the artificial satellites today have dozens or even hundreds of transponders . 
6. In the sixth stage has been used with a high frequency signal that has a short wave . This development resulted in an antenna on Earth could be made to the cross section ( the cup ) whose diameter is much smaller than the antenna on the previous generation .