Communications Satellites

The first science fiction story to deal with a satellite was probably Edward Everett Hale's The Brick Moon (1869). Joe Haldeman's "Tricentennial" (1976) takes place in part on a cylindrical satellite habitat.

Arthur C. Clarke, best known for his novels Rendezvous with Rama and Childhood's End among others, and for writing the motion picture 2001: A Space Odyssey, is commonly credited as the inventor of the communications satellite - an invention without which modern telecommunications would not exist.

In a technical article (nonfiction) published in 1945 in Wireless World magazine, Clarke first proposed the concept of geosynchronous communications satellites.

A geosynchronous satellite is a satellite placed in orbit at such a distance from the Earth that its orbital speed matches the speed of the Earth's rotation. Therefore, although it is in constant motion, the satellite is always positioned above the same spot on the Earth's surface.

In the article, he noted that it would take a minimum of three satellites to provide coverage to every location on the globe. He suggested positioning the first over Africa or Europe; the second over China or the oceans; and the third over the Americas at a longitude of 90 degrees west.

The title of Clarke's paper was "Can Rocket Stations Give Worldwide Radio Coverage?" He says, "It is the most important thing I ever wrote."

Writing articles for trade journals pays either nothing or a small honorarium; Clarke received the latter for his satellite-communications paper. He once commented that if he had only patented the design for a communications satellite network, he would have made billions of dollars.

In a satellite communications system, each satellite carries transponders that operate at different frequencies. Each frequency corresponds to one or more receiving stations on Earth that are tuned to the same frequency.

The first nation to put a satellite into orbit was Russia, with the 1957 launch of Sputnik. In 1958, just 13 years after the publication of Clarke's landmark paper, NASA began actively developing, building, and launching communications satellites.

Private industry entered the communications satellite business in 1962, when AT&T; designed, built, and paid for the launches of its Telstar series of satellites. The original Telstar satellite weighed 175 pounds and was about the size of a beach ball. It was the first satellite capable of receiving and transmitting voice, television, and data signals across the span of the Atlantic Ocean.

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