Satellites

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Satellites A satellite is defined as an object that orbits or revolves around another object. In basic terms, this relationship is due to the gravitational pull of the larger object while the smaller one has enough velocity and momentum to circle the larger one (Fitzgerald &Dennis). This is a good definition if one is only speaking of the broad principles of why and how objects attract one another and where in nature this occurs. The billions of stars and planets together make up a vast network of orbiting objects that each can rightfully be called satellites. By studying the way the Universe and Solar System works, scientists have been able to send man made devices into earth's orbit to serve the needs of a technologically developing world. We have benefitted our world by using satellite technology to preform tasks and provide a range of innovated services. The main applications of satellites are in the fields of communication, Earth Remote Sensing, weather, and scientific research. In some ways the use of satellites has made our world smaller. Satellites make it possible to establish a connection between two people that are on opposite ends of the globe via a telephone call or the use of the internet. Each of these satellites have many parts, but two parts are common to all satellites are called the payload and the bus. These groups of devices make the satellite capable of accomplishing their tasks. An example of a communications satellite is the EchoStar 3. It is used to send TV signals to homes in North America. For this simple use of broadcasting TV through these technical machines, there are over one hundred communications satellites orbiting earth today. Communication satellites are also used as relay stations in space. People use them to bounce messages from one part of the world to another. These messages can be telephone calls, TV pictures, or even Internet connections. Many communications satellites have footprints. Communication satellites like the EchoStar 3 are in a geosynchronous orbit. This means that the satellite always stays over one spot on Earth. The area on Earth that it can see is called the satellite's footprint. For example a footprint that covers all of Africa can be used by one person to send a message to another person in Africa. One could also use communications satellites as relay stations to send messages to people over a system of satellites with many footprints.

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