РефератыИностранный языкSaSatellites Essay Research Paper Satellites orbit the

Satellites Essay Research Paper Satellites orbit the

Satellites Essay, Research Paper


Satellites orbit the earth doing our bidding in ways


that enrich the lives of almost all of us. Through


electronic eyes from hundreds of miles overhead,


they lead prospectors to mineral deposits invisble


on earth’s surface. Relaying communications at the


speed of light, they shrink the planet until its most


distant people are only a split second apart. They


beam world weather to our living room TV and


guide ships through storms. Swooping low over


areas of possible hostility, spies in the sky maintain


a surveillance that helps keep peace in a volatile


world. How many objects, exaclty, are orbiting


out there? Today’s count is 4,914. The satellites


begin with a launch, which in the U.S. takes place


at Cape Canaveral in Florida, NASA’s Wallops


Flight Center in Virginia, or, for polar orbiters,


Vandenberg Air Force Base in California. One


satellite in 20 is crippled by the jolt of lift-off, or


dies in the inferno of a defective rocket blast, or is


thrust into improper orbit. A few simply vanish into


the immensity of space. When a satellite emerges


from the rocket’s protective shroud, radiotelemety


regularly reports on its health to round-the-clock


crews of ground controllers. They watch over the


temperatures and voltages of the craft’s electronic


nervous system and other vital "organs", always


critical with machines whose sunward side may be


300 degress hotter than the shaded part. Once a


satellite achieves orbit–that delicate condition in

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which the pull of earth’s gravity is matched by the


outward fling of the Page 2 crafts


speed–subtle pressures make it go astray. Solar


flares make the satellite go out of orbit. Wisps of


outer atmosphere drag its speed. Like strands of


spiderweb, gravity feilds of the earth, moon, and


sun tug at the orbiting spacefarer. Even the


sunshine’s soft caress exerts a gentle nudge.


Should a satellite begin to wander, ground crews


fire small fuel jets that steer it back on course. This


is done sparingly, for exhaustion of these gases


ends a craft’s useful career. Under such stresses,


many satellites last 2 years. When death is only a


second away, controllers may command the craft


to jump into a high orbit, so it will move up away


from earth, keeping orbital paths from becoming


too cluttered. Others become ensnarled in the


gravity web; slowly they are drawn into


gravitational that serve as space graveyards. A


satellite for communications would really be a


great antenna tower, hundreds or even thousands


of miles above the earth, capable of transmitting


messages almost instantaneously across the


oceans and continents. Soon after the launch of


ATWS-6, "the Teacher in the sky", (a satellite


designed to aid people) NASA ground controllers


trained its antenna on Appalachia. There is


brought evening college classes to schoolteachers


whose isolation denied opportunity for


advancement. The use of Satellites is growing


rapidly and so is the different jobs for them.

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