Satellites :: essays research papers

Satellites orbit the earth doing our bidding in waysthat enrich the lives of almost all of us. Throughelectronic eyes from hundreds of miles overhead,they lead prospectors to mineral deposits invisbleon earths surface. Relaying communications at thespeed of light, they shrink the planet until its mostdistant people are only a split second apart. They broadcast world weather to our living room TV andguide ships through storms. Swooping low overareas of possible hostility, spies in the sky maintaina superintendence that helps keep peace in a volatileworld. How many objects, exaclty, are orbitingout there? Todays count is 4,914. The satellitesbegin with a launch, which in the U.S. takes placeat Cape Canaveral in Florida, NASAs WallopsFlight Center in Virginia, or, for polar orbiters,Vandenberg Air Force Base in California. Onesatellite in 20 is cripple by the jolt of lift-off, ordies in the inferno of a defective rocket blast, or isthrust into improper orbit. A few simply disappear intothe immensity of space. When a satellite emergesfrom the rockets protective shroud, radiotelemetyregularly reports on its health to round-the-clockcrews of foothold controllers. They watch over thetemperatures and voltages of the crafts electronicnervous system and new(prenominal) vital "organs", alwayscritical with machines whose sunward side may be300 degress hotter than the shaded part. Once asatellite achieves orbit--that delicate condition inwhich the hassock of earths gravity is matched by theoutward fling of the Page 2 ------ craftsspeed--subtle pressures make it go astray. Solarflares make the satellite go out of orbit. Wisps ofouter automated teller machine drag its speed. Like strands ofspiderweb, gravity feilds of the earth, moon, andsun tug at the orbiting spacefarer. Even thesunshines soft caress exerts a gentle nudge.Should a satellite begin to wander, ground crewsfire small fuel jets that steer it back on course. Thisis done sparingly, for exhaustion o f these gasesends a crafts useful career. Under such stresses,many satellites last 2 years. When death is only asecond away(p), controllers may command the craftto jump into a high orbit, so it will move up awayfrom earth, keeping orbital paths from becomingtoo cluttered. Others become ensnarled in the