Decay watch: April 23/24

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 23 Apr 1998 23:24:30 +0100

The most recent elset for the Iridium 51 Long March rocket is:
Ir 51 CZ-2C r   12.0  3.5  0.0  4.3 d            212 x 136 km
1 25264U 98018C   98113.71000865  .08454168 -12303-5  23899-3 0  1070
2 25264  86.3625 358.4912 0057908  57.4334 303.3457 16.36928954  4572
This shows it 3.2 sec early against the "9095" SatEvo evoltion I posted
yesterday.
I now predict decay for about April 24.08 (~02:00 UTC +-2h).
Predicted elsets:
Ir 51 CZ-2C r   12.0  3.5  0.0  4.3 d            187 x 132 km
1 25264U 98018C   98113.89305421  .17612395  20621+0  32950-3 0 91075
2 25264  86.3608 358.3855 0042312  56.6176 303.7864 16.42322584  4600
Ir 51 CZ-2C r   12.0  3.5  0.0  4.3 d            177 x 130 km
1 25264U 98018C   98113.95393578  .22805122  39553+0  34779-3 0 91075
2 25264  86.3600 358.3502 0035643  56.3447 303.9946 16.44747818  4615
Ir 51 CZ-2C r   12.0  3.5  0.0  4.3 d            162 x 127 km
1 25264U 98018C   98114.01471039  .34114854  99284+0  37994-3 0 91079
2 25264  86.3589 358.3147 0027411  56.0713 304.1889 16.48099807  4625
Ir 51 CZ-2C r   12.0  3.5  0.0  4.3 d            138 x 118 km
1 25264U 98018C   98114.07531669  .84684564  76845+1  49508-3 0 91079
2 25264  86.3571 358.2791 0015252  55.7969 304.3475 16.54243731  4637
The final rev takes it northbound across the equator at 119 deg E at
01:48 UTC at southbound across the equator at 72 deg W at 02:32 UTC.
That southbound ground-track passes between Quebec and Montreal at 
02:21 UTC and between New York and Boston a minute or so later.

The latest elset for the other decaying Iridium rocket ...
Iridm 43 Delta r 5.9  2.4  0.0  5.6 d            238 x 183 km
1 25044U 97069F   98113.71896087  .02337494 -13891-5  78195-3 0  2574
2 25044  83.5247 342.4817 0041786  82.7688 277.8396 16.23277329 25898
... shows it 14 seconds late on yesterday's prediction.
My new evolution indicates decay at April 25.7 +-0.4d.
Prediction:
Iridm 43 Delta r 5.9  2.4  0.0  5.6 d            231 x 180 km
1 25044U 97069F   98114.02698221  .03079270  48726-2  89896-3 0 92575
2 25044  83.5241 342.1725 0038427  81.4853 278.9501 16.25171359 25949
Iridm 43 Delta r 5.9  2.4  0.0  5.6 d            218 x 175 km
1 25044U 97069F   98114.51907705  .04072999  93640-2  91228-3 0 92578
2 25044  83.5228 341.6767 0032346  79.4272 280.9370 16.28638800 26029
Iridm 43 Delta r 5.9  2.4  0.0  5.6 d            199 x 167 km
1 25044U 97069F   98115.00993506  .06307365  25190-1  92529-3 0 92576
2 25044  83.5211 341.1791 0024838  77.3624 282.9152 16.33555248 26107

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
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