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U.S. weather satellite boosted to graveyard orbit BY STEPHEN CLARK SPACEFLIGHT NOW Posted: May 8, 2001 The American GOES-2 weather satellite was officially retired Saturday after controllers guided the 24-year old spacecraft out of its geostationary orbit. Officials opted to take the satellite out of commission because of the lack of propellant for future thruster firings. It is preferred to foresee any possible fuel problems ahead of time to allow ample opportunities to raise the craft's orbit out of the geostationary belt and into a so-called "graveyard" orbit, freeing up space in the often-used geostationary ring 22,300 miles above Earth. Over the past week, the spacecraft used onboard thrusters to raise its altitude about 185 miles above its original geostationary orbit. The purpose for such a maneuver is twofold: to remove the satellite from geostationary orbit and to offer complete depletion of the craft's propellant, decreasing possibilities for future debris-producing explosions. The final firing of the propulsion system took place early Saturday, followed just hours later at 2108 GMT (5:08 p.m. EDT) by the command to switch off the satellite's communications system, effectively ending the life of the 24-year old weather observation spacecraft-turned-communications relay satellite. The six thruster firings were controlled from the Kokee Park Geophysical Observatory station in Hawaii. Launched aboard a Delta rocket in June 1977, GOES-2 was the second component of NOAA's Geostationary Operational Environmental Satellite system. Until 1993, the satellite provided weather sensing information to forecasters on the ground, allowing them to make more informed and more accurate forecasts. After a brief two-year stand-down, the craft was brought to life again as a relay satellite for the National Science Foundation to broadcast their transmissions from the South Pole to public broadcasting stations around the U.S. |
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