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Satellites: Artificial Satellites |
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Imagine something looking down on Earth that could tell us about the weather or point out areas such as mineral deposits. Such things exist. They are called satellites. There are many different types of satellite orbiting the Earth, all performing different tasks. Navigation satellites help ships or aeroplanes pinpoint their positions. Astronomers use satellites to look out into the Universe. Some satellites provide us with instant phone calls, others allow us to watch events that are happening around the world 'live' on television. What the Topex/Poseidon satellite is made up of:-
Orbits:- The path that a satellite takes around the earth depends on the job it has to do. For example, the geostationary orbit is 25,880km (22,280 miles) above the equator. Satellites in this will complete one orbit in the same time that Earth completes it's daily spin. So the satellite will always be above the same point on Earth. This is useful for television satellites.
Topex/Poseidon From an orbit 1,320km (820 miles) above the Earth's surface, this US- French satellite is investigating ocean currents and wind speeds over the seas. It has found "Sea-level" is not the same everywhere: the western Atlantic Ocean os 70cm (27in) higher than the eastern side! Repairing Satellites What happens when something goes wrong with a satellite in orbit? It can be mended in space by astronauts. If the fault is a major one, the satellite is brought back to Earth for repair and re-launch. In November 1984, the crew of the space shuttle Discovery recovered a telecommunications satellite and returned it to Earth.
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