Mike McCants reports that AEHF 1 (10039A / 36868) reached synchronous orbit on 2011 Oct 25, near longitude 68 W, one of the operational Milstar/AEHF locations. Based on observations overnight, he provided the following elset, with the caution that eccentricity and argument of perigee remain uncertain: 1 36868U 10039A 11298.86959040 0.00000000 00000-0 00000-0 0 09 2 36868 4.4100 278.5854 0002000 241.0264 118.9823 1.00270000 04 No doubt this is a time of celebration for the team of USAF, Aerospace Corporation and Lockheed Martin personnel who have worked for the past 14 months to overcome the loss of the spacecraft's liquid apogee engine, initially by using its hydrazine attitude control thrusters, followed by thousands of hours of hall current thruster firings over 12 months. Additional information is available in this recent progress report by Spaceflight Now: http://www.spaceflightnow.com/atlas/av019/111009.html Manoeuvring AEHF 1 to its correct orbit, with sufficient propellant remaining to complete its planned mission, adds a new chapter to the long and distinguished history of overcoming serious in-orbit problems in civil, military and commercial spaceflight. I hope that some of technical reports on the rescue operations will appear in journals accessible to the public. A small team of hobbyists led by Mike McCants managed to keep track of AHEF 1 during its long climb to GEO, resulting in an accurate orbital history in TLE format. Here are the final plots of the evolution of the altitude, orbital period and inclination, from launch to arrival in geosynchronous orbit: http://satobs.org/seesat_ref/misc/AEHF_1_the_climb_to_GEO.pdf The tracking was most challenging during the year-long HCT phase, during which the thrusters were fired nearly every day for between 12 and 24 hours. As the orbit evolved, Mike analyzed the trend in the elements and issued search TLEs projected several days ahead. This enabled Mike and colleagues Derek Breit, Scott Campbell, Kevin Fetter, Tim Luton, Greg Roberts, Peter Wakelin and Brad Young to observe the spacecraft during a total of 105 sessions from 2010 Oct 17 through 2011 Oct 26. Very nice work by all involved! Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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