Satellites orbit the earth doing our bidding in waysthat enrich the lives of almost all of us.Through electronic eyes from hundreds of miles overhead, theylead prospectors to mineral deposits invisble on earth’s surface.
Relaying communications at the speed of light, they shrink the planetuntil its most distant people are only a split second apart.They beam world weather to our living room TV and guide shipsthrough storms. Swooping low over areas of possible hostility, spiesin the sky maintain a surveillance that helps keep peace in avolatile 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 atCape 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 diesin the inferno of a defective rocket blast, or is thrust intoimproper 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-clockcrews of ground controllers. They watch over the temperatures andvoltages of the craft’s electronic nervous system and othervital “organs”, always critical with machines whose sunward side maybe 300 degress hotter than the shaded part.Once a satellite achieves orbit–that delicate condition in whichthe pull of earth’s gravity is matched by the outward fling of the Page 2——crafts speed–subtle pressures make it go astray.
Solar flaresmake the satellite go out of orbit. Wisps of outer atmosphere dragits speed. Like strands of spiderweb, gravity feilds of the earth, moon, and sun tug at the orbiting spacefarer. Even the sunshine’ssoft caress exerts a gentle nudge.
Should a satellite begin to wander, ground crews fire small fuel jetsthat steer it back on course. This is done sparingly, for exhaustionof these gases ends a craft’s useful career.Under such stresses, many satellites last 2 years. When death isonly a second away, controllers may command the craft to jump intoa high orbit, so it will move up away from earth, keeping orbitalpaths from becoming too cluttered.
Others become ensnarled in thegravity web; slowly they are drawn into gravitational that serveas space graveyards.A satellite for communications would really be a great antenna tower,hundreds or even thousands of miles above the earth, capable oftransmitting messages almost instantaneously across the oceans andcontinents.Soon after the launch of ATWS-6, “the Teacher in the sky”, (a satellitedesigned to aid people) NASA ground controllers trained its antenna onAppalachia. There is brought evening college classes to schoolteacherswhose isolation denied opportunity for advancement.
The use of Satellites is growing rapidly and so is the differentjobs for them.
