USA 129 has manoeuvred. It was last seen on 2003 Dec 18 at about 12:12 UTC, by Tony Beresford, in this orbit: Observation arc 2003 Dec 07.86 - 18.51 UTC: USA 129 15.0 3.0 0.0 5.3 v 1 24680U 96072A 03352.44858091 .00027406 00000-0 28356-3 0 05 2 24680 97.7982 52.1811 0495592 121.4331 243.6328 14.84556340 09 WRMS residuals = 0.013 deg It was first not seen in the above orbit on Dec 21 at about 19:28 UTC, by Greg Roberts, and confirmed missing by Tony on Dec 22, when he did not seen it -4 min / +3.5 min of about 13:14 UTC. Assuming a reboost typical of the previous five manoeuvres, then the mean motion will have decreased to somewhere between about 14.803 - 14.811 rev/d. The latest that the manoeuvre could have occurred was at the perigee just prior to Greg's non-sighting, which defines the earliest search passes: Earliest likely arrival 1 70004U 03355.77065972 .00025000 00000-0 26303-3 0 07 2 70004 97.7982 55.4465 0510350 110.5013 0.0000 14.81100000 04 The earliest that the manoeuvre could have occurred was at the perigee just after Tony's last observation, which defines the latest search passes: Latest likely arrival 1 70001U 03352.53751157 .00025000 00000-0 26303-3 0 02 2 70001 97.7982 52.2685 0510350 121.1405 0.0000 14.81100000 03 These orbits narrow the search period to about a 10 min duration. The UTC time of passage changes from night to night, but the search duration remains constant. It would be prudent to extend searches a few minutes before and after the duration defined by the search elements. Happy hunting! Ted Molczan ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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