Pierre Neirinck produced these elements, using observations by himself, Jim Nix and Alberto Rango, from 09 - 12 April UTC: USA 129 15.0 3.0 0.0 5.1 v 1 24680U 96072A 00104.09606140 .00050275 00000-0 70721-3 0 4337 2 24680 97.8761 168.0429 0471223 190.4260 168.3200 14.83875972 05 Pierre observed the object on 12 April at about 20:05 UTC, as predicted. I failed to see it on 13 April at 04:07:17 UTC; however, the observing conditions were such that I cannot rule out the possibility that it was simply too faint. The predicted magnitude was 7.0, and it would have been nearly 50 percent illuminated. Using 11X80 binoculars, my limiting magnitude was 8 or better. The difference between the predicted magnitude and the limiting magnitude was near the range of normal brightness variation of satellites, so it could well have been too faint too see at the time I observed. In case it had manoeuvred, I continued to wait for 96072A to appear, but was fooled by 82025B, which passed 118 s later, on what appeared to be roughly the predicted path. If 96072A did manoeuvre, and if this occurred as late as the perigee of 22:18:32 UTC on 12 April, then it would still have passed some 30 s after 82025B and 1 deg higher. So, I could easily have missed it while noting my observations of 82025B - in what would be a costly distraction! Since my non-sighting is inconclusive, we must assume that USA 129 has NOT yet manoeuvred, so the manoeuvre alert continues. Based on its past behaviour, an orbit-raising manoeuvre can be expected before its mean motion reaches 14.84 rev/d, sometime before day 105.3 (14 April UTC), at the present rate of decay. My records show only one case of previous operational satellites in this series for which the mean motion was permitted to go higher than 14.84 rev/d. In 1995, on day 233, both 88099A and 92083A reached mean motions in excess of 14.846 rev/d, and then manoeuvred a day or two later. If USA 129's mean motion is permitted to go as high this time, then the manoeuvre could be as late as day 111.3 (20 April), at the present rate of decay. Ted Molczan ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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