Decay watch update: December 18
Alan Pickup (alan@wingar.demon.co.uk)
Fri, 18 Dec 1998 21:56:54 +0000
OIG shows the following decay notices to be in effect:
Object Notice issued Predicted decay
UTC UTC
#25120 = Orbcomm 9 Pegasus r Dec 16 10:38 Dec 29 11:40 +-8d
#25499 = C 2350 aux motor Dec 18 20:14 Dec 19 14:09 +-11h
Current elsets for these are:
Orbc9 Pegasus r 1.3 1.0 0.0 7.0 d 326 x 225 km
1 25120U 97084J 98352.22386277 .00636851 18886-3 86588-3 0 3931
2 25120 44.9516 322.7925 0075907 109.9089 251.0029 15.99808377 55551
C 2350 Prot deb (aux motor) 2292 x 97 km
1 25499U 98025E 98352.87086016 .99999999 29478-4 24594-2 0 1282
2 25499 47.2036 207.2373 1449266 83.7550 293.2924 13.17565073 5944
I now show decay of the Pegasus on December 28 +-2 days.
For once, I agree with USSPACECOM's decay prediction for the auxiliary
motor. My own calculation puts decay at December 19.58 (14:00 UTC +-5h).
SatEvo predicted elsets:
C 2350 Prot deb (aux motor) 2023 x 96 km
1 25499U 98025E 98353.02002082 1.28850748 46408+0 27079-2 0 91289
2 25499 47.1888 206.6437 1295219 84.3265 290.2619 13.53492739 5967
C 2350 Prot deb (aux motor) 1573 x 96 km
1 25499U 98025E 98353.23602318 1.72447654 10014+1 31116-2 0 91289
2 25499 47.1661 205.7186 1023526 85.2181 286.3754 14.17345230 5997
C 2350 Prot deb (aux motor) 1012 x 96 km
1 25499U 98025E 98353.44089433 2.73188723 33918+1 37865-2 0 91285
2 25499 47.1351 204.7402 0660383 86.1622 281.3579 15.04228758 6027
C 2350 Prot deb (aux motor) 765 x 96 km
1 25499U 98025E 98353.50611206 3.74004194 89378+1 43944-2 0 91288
2 25499 47.1246 204.3973 0490847 86.4934 279.1059 15.45351312 6031
C 2350 Prot deb (aux motor) 375 x 90 km
1 25499U 98025E 98353.56899731 9.99999999 50000+2 64667-2 0 91281
2 25499 47.1000 204.0417 0216018 86.8371 275.6320 16.15295303 6042
The final orbit above has perigee (in daylight) over the Bay of Biscay
with the track taking it eastwards over France (14:01 UTC) and
Switzerland towards Bulgaria (14:06 UTC). Given the rapid increase in
mean motion over the coming hours, the along track timing could be
several minutes in error.
Alan
--
Alan Pickup | COSPAR 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | SatEvo page: http://www.wingar.demon.co.uk/satevo/