Decay watch update: early January 9
Alan Pickup (alan@wingar.demon.co.uk)
Sat, 9 Jan 1999 01:19:39 +0000
In the hope of refining my prediction for the decay of #21148, the
Lacrosse 2 rocket (which briefly became "Lacrosse 3 rocket" in my
previous message) I've been awaiting further elsets from OIG. One
further elset did appear, for epoch 99008.78174788, showing it running
2.4 seconds late on my earlier prediction for that orbit; this was six
hours ago and no more elsets have materialised since.
SpaceCom did, however, issue the following decay notice:
Object Notice issued Predicted decay
UTC UTC
#21148 = Lacrosse 2 r Jan 8 21:38 Jan 9 03:54 +-5h
They intend to issue their next report two hours before decay.
Incorporating the latest elset, I think there is a good chance of the
rocket surviving beyond my earlier decay time of 03:30 UTC, with decay
more likely on the approach to following southbound crossing near 73 deg
W at 04:13. This improves the prospects for decay during the SE-bound
pass across the E USA. The uncertainty, however, is still a couple of
hours either way. A new prediction for the final revs:
Lacrosse 2 r 9.8 3.0 0.0 5.0 145 x 139 km
1 21148U 91017B 99009.02488788 .20306975 37170+0 28263-3 0 91079
2 21148 67.9431 279.2868 0004067 117.9072 242.1340 16.48997115 64955
Lacrosse 2 r 9.8 3.0 0.0 5.0 136 x 132 km
1 21148U 91017B 99009.08549168 .31062752 99289+0 26647-3 0 91072
2 21148 67.9422 279.0765 0003083 117.8247 242.2066 16.52003174 64964
Lacrosse 2 r 9.8 3.0 0.0 5.0 120 x 118 km
1 21148U 91017B 99009.14594619 .89357870 11302+2 33770-3 0 91078
2 21148 67.9406 278.8655 0001569 117.7419 242.2740 16.57878443 64972
Alan
--
Alan Pickup | COSPAR 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
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