Re: Decay watch: Iridium Long March rocket

Alan Pickup (alan@wingar.demon.co.uk)
Tue, 20 Jan 1998 05:11:10 +0000

The two further elsets which have appeared since my last posting..

Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            208 x 141 km
1 25079U 97077C   98019.71866627  .05573299 -12488-5  20489-3 0  1338
2 25079  86.2648  98.9696 0050707 356.6681   3.4285 16.36737773  6682
Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            191 x 139 km
1 25079U 97077C   98019.96296012  .17424429 -81019-6  48990-3 0  1348
2 25079  86.2694  98.8287 0039927 352.6173   7.4904 16.40209953  6727

..show it 1.0 and 6.0 seconds late on my most latest prediction. The
drag term in the latter elset appears almost double what (I think) it
should be. Otherwise the indication is that decay will occur near a
northbound equator crossing at 09:19 UTC at 161 deg W longitude. This is
almost two complete orbits after its near-overflight of L.A. at 06:32.
The uncertainty in this new decay estimate is one orbit or so.

New predictions for the final revs:
Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            166 x 132 km
1 25079U 97077C   98020.20655228  .16872814  22968+0  24670-3 0 91347
2 25079  86.2674  98.6837 0026420 351.5273   8.4282 16.46379094  6761
Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            157 x 129 km
1 25079U 97077C   98020.26729746  .22677706  45214+0  25530-3 0 91345
2 25079  86.2666  98.6474 0021783 351.2538   8.7083 16.48741119  6773
Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            144 x 123 km
1 25079U 97077C   98020.32793920  .36947264  13776+1  28059-3 0 91349
2 25079  86.2655  98.6109 0015850 350.9796   8.9917 16.52193522  6789
Iridm CZ-2C r   10.0  3.0  0.0  3.0 d            113 x 107 km
1 25079U 97077C   98020.38839672 2.56402791  50000+2  69591-3 0 91343
2 25079  86.2638  98.5742 0005111 350.7043   9.2862 16.61204691  6798

Alan
-- 
 Alan Pickup | COSPAR site 2707:   55d53m48.7s N   3d11m51.2s W    156m asl
 Edinburgh   | Home:      alan@wingar.demon.co.uk       +44 (0)131 477 9144
 Scotland    | SatEvo satellite page: http://www.wingar.demon.co.uk/satevo/