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Satellite Communications: History & Applications, Tsiolkovsky to Modern Tech, Study Guides, Projects, Research of Physics

This literature review explores the origins of satellite communications, from the early ideas of scientists like tsiolkovsky and oberth to the practical applications proposed by clarke and the launch of the first satellites. Discover how satellite communications revolutionized radio and tv broadcast, weather forecasting, navigation, military operations, and the connection of remote areas.

What you will learn

  • Who is generally credited with originating the modern concept of Satellite Communications?
  • Who was the first person to study space travel as a science?
  • What are some practical applications of geosynchronous orbit in satellite communications?

Typology: Study Guides, Projects, Research

2016/2017

Uploaded on 06/14/2017

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CHAPTER TWO: LITERATURE REVIEW
Scientists from different countries conceived various ideas for communications through space
along with the technological breakthroughs in different fields of science. The Russian scientist
Konstantin Tsiolkovsky (1857-1935) was the first person to study space travel as a science and in
1879 formulated his Rocket Equation, which is still used in the design of modern rockets. He
also wrote the first theoretical description of a man- made satellite and noted the existence of a
geosynchronous orbit. But he did not identify any practical applications of geosynchronous orbit.
The noted German Scientist and rocket expert, Hermann Oberth, in 1923 proposed that the crews
of orbiting rockets could communicate with remote regions on earth by signaling with mirrors.
In 1928, Austrian Scientist Hermann Noordung suggested that the geostationary orbit might be
a good location for manned space vehicle. Russian Scientists in 1937 suggested that television
images could be relayed by bouncing them off the space vehicles. During 1942-1943, a series of
articles by George O Smith were published in Astounding Science Fictions concerning an
artificial planet, Venus Equilateral, which functioned as relay station between Venus and Earth
Station when direct communication was blocked by Sun. However, Arthur C. Clarke, an
electronic engineer and the well-known science fiction writer is generally credited with
originating the modern concept of Satellite Communications. In 1945, Clarke, in his article
`Extra Terrestrial Relays: Can Rocket Stations give Worldwide Radio Coverage?’ published
in Wireless World outlined the basic technical considerations involved in the concept of satellite
communications. Clarke proposed orbiting space stations, which could be provided with
receiving and transmitting equipment and could act as a repeater to relay transmission between
any two points of the hemisphere beneath. He calculated that at an orbital radius of 42,000 km.
the space station’s orbit would coincide with the earth’s rotation on its axis and the space station
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CHAPTER TWO: LITERATURE REVIEW

Scientists from different countries conceived various ideas for communications through space along with the technological breakthroughs in different fields of science. The Russian scientist Konstantin Tsiolkovsky (1857-1935) was the first person to study space travel as a science and in 1879 formulated his Rocket Equation, which is still used in the design of modern rockets. He also wrote the first theoretical description of a man- made satellite and noted the existence of a geosynchronous orbit. But he did not identify any practical applications of geosynchronous orbit. The noted German Scientist and rocket expert, Hermann Oberth, in 1923 proposed that the crews of orbiting rockets could communicate with remote regions on earth by signaling with mirrors. In 1928, Austrian Scientist Hermann Noordung suggested that the geostationary orbit might be a good location for manned space vehicle. Russian Scientists in 1937 suggested that television images could be relayed by bouncing them off the space vehicles. During 1942-1943, a series of articles by George O Smith were published in Astounding Science Fictions concerning an artificial planet, Venus Equilateral, which functioned as relay station between Venus and Earth Station when direct communication was blocked by Sun. However, Arthur C. Clarke, an electronic engineer and the well-known science fiction writer is generally credited with originating the modern concept of Satellite Communications. In 1945, Clarke, in his article `Extra Terrestrial Relays: Can Rocket Stations give Worldwide Radio Coverage?’ published in Wireless World outlined the basic technical considerations involved in the concept of satellite communications. Clarke proposed orbiting space stations, which could be provided with receiving and transmitting equipment and could act as a repeater to relay transmission between any two points of the hemisphere beneath. He calculated that at an orbital radius of 42,000 km. the space station’s orbit would coincide with the earth’s rotation on its axis and the space station

would remain fixed as seen from any point on the earth. He also pointed out that three such synchronous stations located 120 degrees apart above the equator could provide worldwide communications coverage. The concept was later considered to be generating a billion dollar business in the area of communications. However, Clarke did not patent the most commercially viable idea of twentieth century as he thought satellites would not be technically and economically viable until the next century.

2.1 THE HISTORY OF SATELLITE In launching of satellite, the theory of satellites was simple enough - shoot something out into space at the right speed and on the correct trajectory and it will stay up there, orbiting Earth for years-if not forever. If the orbit is the right distance in space the satellite will keep pace with the rotation of the Earth. Herman potočnik described a space station in geosynchronous orbit in the year 1928, and Arthur C. Clarke proposed a station in geosynchronous orbit to relay communication and broadcast television in 1945. The world’s first artificial satellite which is the Sputnik I was launched successfully by the Soviet Union on 4th October, 1957. The satellite was about the size of a basketball, it weighed 183 pounds, and took about 1hour 38 minutes to orbit the earth on its elliptical path. This event marks the beginning of the space age. A month later, the Soviet Union launched another which the called Sputnik II ,but this time with a passenger with the name Laika, a dog who is known for being the first known living creature to escape earth to outer space, this caused an increase in the space research. United States launched another satellite they called Explorer in February 1958. (Launius, 2010) The first communication satellite launched on the 18 th^ of December, 1958 was called^ SCORE ( signal communication by orbital relay). The main task of this SCORE project was to demonstrate that an atlas missile could be put into orbit, the satellite SCORE broadcasted a

miles above the equator. That meant it was always on station to provide line of sight communications between Europe and North America. Early Bird didn't have a battery - and worked only when its solar panels were exposed to the sun The launch of the Intelsat 3 satellites in 1969 created a global TV and speech communications network that spanned the Atlantic, Pacific and Indian Oceans. The introduction of multiple-beam antennas in the 1980s brought new improvements in efficiency, as a satellite's power could now be concentrated on small regions of the Earth, making possible smaller-aperture (coverage area), lower-cost ground stations. The Capacity (the number of simultaneous television and speech channels carried) grew as well.

2.2 HOW SATELLITE WORKS

The basic elements of a satellite communications system are shown in Figure 2-1 below. The process begins at an earth station--an installation designed to transmit and receive signals from a satellite in orbit around the earth. Earth stations send information in the form of high powered, high frequency (GHz range) signals to satellites which receive and retransmit the signals back to earth where they are received by other earth stations in the coverage area of the satellite. The area which receives a signal of useful strength from the satellite is known as the satellite's footprint. The transmission system from the earth station to the satellite is called the uplink, and the system from the satellite to the earth station is called the downlink.

Figure 2- SATELLITE POSITIONING

The positions of the satellites are controlled by international agreements drawn up by the IRFB (International Radio Frequencies Board). The IRFB also coordinates the frequencies used for satellite broadcasting, to prevent interference which would be caused by two or more satellites using the same frequency. The transmission frequencies used by consumer satellites are in the KU-band, which roughly stretches from 10 to 17 GHz. The range within the KU-band that is actually used by consumer satellites is between 10.7 GHz and 12.75 GHz.

10.7 - 11.7 GHzFSS+MPS 11.7 - 12.5 DBS

  1. Military Satellites : These satellites are used to gather intelligence, also used as a communication satellite for military purposes, and also used as a weapon.
  2. (^) Connection of Remote Areas: Some areas in earth do not have direct wired connection to the network for some geographical problem, these satellites placed in such areas provides complete coverage for the area.
  3. Global Mobile Communication: Mobile phones like GSM and AMPS do not cover all parts of a country, and these areas not covered occasionally have low population, this is where this satellite comes very useful because it is built to boost the areas coverage. (P.Nicopolitidis, 2006)