USA 116 (95066A / 23728) was last observed by David Brierley, on 2008 Nov 18, near 17:18 UTC: http://satobs.org/seesat/Nov-2008/0112.html It was in the following orbit: USA 116 15.0 4.0 0.0 5.1 v 1 23728U 95066A 08323.69802823 .00000600 00000-0 31670-4 0 02 2 23728 97.9290 101.5081 0307000 194.3756 165.6243 14.83044340 09 Tony Beresford attempted to observe it in the same orbit, on 2008 Nov 24 near 18:20 UTC, but did not see it: http://satobs.org/seesat/Nov-2008/0171.html I estimate that the object should have reached magnitude 4.2 +/- 1.5, so Tony had a reasonable probability of observing it with the unaided eye. If it has manoeuvred, then based on its history of the past 6 years or so, the following search elsets bracket the likely range of mean-motion and eccentricity: 400 X 837 km 1 70001U 08323.73413194 .00000574 00000-0 30000-4 0 02 2 70001 97.8500 101.5440 0312000 194.2578 358.4000 14.82460000 01 400 X 847 km 1 70002U 08323.73413194 .00000569 00000-0 30000-4 0 07 2 70002 97.8500 101.5440 0319000 194.2578 358.4000 14.81000000 08 Epoch of both is the first perigee after David's observation of Nov 18, so they yield worst-case predictions in terms of lateness relative the last known orbit. If the object were in the 70001 orbit, then it would have passed within the period that Tony waited for it. If in the 70002 orbit, it would have passed about 5 minutes after Tony stopped waiting. The object has seldom manoeuvred since it was replaced as the primary eastern KH satellite in 2001 Oct, by USA 161 (01044A / 26934), and there was nothing about its recent orbit that suggested the need to make a manoeuvre. The object holds the record as the longest surviving KH, just shy of 13 years, so the possibility that it has been de-orbited cannot be excluded. Observers interested in attempting to recover the object are advised to first check the last known orbit (in case Tony missed it due its having been unusually faint); if not seen, then switch to a planar search, using either the 70001 or the 70002 elset. Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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