Communication+Sateelites

Communication Satellite

Communication Satellite is an artificial satellite in the space for the telecommunication in the Earth. Satellite is an object which has been placed into orbit by human endeavor. Communication Satellites are used in a variety amount of ways, including Geostationary Orbits, Molniya oribts, other Elliptical Rrbits, and Low Earth Orbits.

The first satellite was launched by the Soviet in October 4, 1957 and the first U.S satellite was in 1958. In 1960, NASA launched an Echo Satellite, it was 30 m long and was used for radio communications. Hughes' Syncom 2 was launched in 1963, it was the world's first active repeater satellite. Satellite that was built by British and French NASA officers launched in July 10, 1962 and that was the first privately sponsored space launch. An immediate antecedent of the geostationary satellite was Hughes' Syncom 2, launched on July 26, 1963. Hughes' Syncom 2 goes around the Earth once per day at constant speed, but because it still had north-south motion, special equipment was needed to track it.

A Geostationary Orbit goes around the earth at a constant speed once per day over the equator. A Low Earth Orbit is a circular orbit about 400 km above the Earth's surface, and because its really low, it is possible to be seen from the Earth within a radius of roughly 1000 km from the sub-satellite point. Molniya Orbit was launched by Soviet Union for military communication. Molniya satellite were placed into high eccentric elliptical orbits known as Moniya Orbits.

The satellites work in a few steps. The first process begins at an earth station. An installation transmit and receive signals from a satellite in orbit around the earth. Earth station send information in the form of high powered, high frequench signals to satellites which receive and retransmit the signals back to earth where they are received by other earth stations in the area where satellite can send signals. The area that are received by satellite signals are called "satellite's footprint." The earth station sending information to the satellite is called "uplink" and satellite to the earth is called "downlink."

http://science.nasa.gov/Realtime/jtrack/3d/JTrack3d.html -If you go to this site, you will see an Earth surrounded by a lot of dots, these dots are satellite. If you click one of the dots, it will show the route of the satellite go around the earth. If you press shift+click, it will zoom in, and ctrl+click will zoom out. If you click the earth and drag it, you will see the Earth by 3D.

http://www.nasa.gov/home/ -This is NASA site. NASA's mission is to develop the future in space exploration, scientific discovery and aeronautics research. President Dwight D. Eisenhower established the NASA (National Aeronautics and Space Administration) in 1958, response to the Soviet Union launching the first artificial satellite the previous year. NASA Headquarter is in Washington giving the agency what to do, under the leadership of Administrator.