Scott Campbell, Bob Christy, Bram Dorreman, Kevin Fetter, Tim Luton, Rob Matson, Mike McCants, Greg Roberts, Patrick Schmeer, Peter Wakelin, Brad Young, and I, contributed observations used to determine one or more of the following element sets. Scott's observations of AEHF 1, in the early hours of Sep 24 UTC, confirm the recent, small manoeuvre, centred on the apogee of Sep 22 at 21:41:57 UTC. Adding his observations to those of Tim Luton, from the night before, enables the elements to be refined: AEHF 1 4707 X 49983 km 1 36868U 10039A 10267.19905349 .00000000 00000-0 00000-0 0 03 2 36868 15.1729 298.8480 6713000 198.7207 113.6791 1.40208517 04 Arc 20100923.07-0924.22 WRMS resid 0.003 totl 0.001 xtrk The period remains uncertain by perhaps several 10s of seconds, so expect at least that much time uncertainty tonight. I have updated the manoeuvre history to include the latest burn: http://satobs.org/seesat_ref/misc/AEHF_1_manoeuvres_v2.5.pdf I note that this burn is the smallest of the Segment 1 and 2 burns to-date, and total delta-V and estimated fuel consumption now slightly exceed (by ~6 percent) what I estimated was possible using fuel available after the aborted LAE (liquid apogee engine) manoeuvres. This may indicate that the REA (reaction engine assembly) manoeuvres have been, or are nearly completed. If so, then the spacecraft will cease its 0.1 rpm passive thermal control roll, and deploy its solar arrays, to enable operation of the 4.5 kW Hall Current Thrusters, which will complete the manoeuvres to reach the planned 4.8 deg, geo-synchronous orbit, sometime next summer. FIA Radar 1 1067 X 1080 km 1 37162U 10046A 10267.02968548 .00000000 00000-0 00000-0 0 01 2 37162 122.9931 105.9891 0008524 81.6596 278.5335 13.49540846 02 Arc 20100923.02-0924.06 WRMS resid 0.023 totl 0.010 xtrk It appears that 10046A's orbit may be frozen in eccentricity and argument of perigee, which is a common feature of remote sensing satellites, especially radars. The orbits of the first four Lacrosses, and the mysterious USA 193, were similarly frozen. This finding is subject to confirmation through further observation, which should reveal that the argument of perigee oscillates about a value close to 90 deg, and the eccentricity oscillates about a value similar to that of the above elements. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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