Decay watch update: December 30

Alan Pickup (alan@wingar.demon.co.uk)
Wed, 30 Dec 1998 19:57:08 +0000

The following SpaceCom decay notices are current or have been released
during the past day:

Object                            Notice issued    Predicted decay
                                       UTC              UTC
     
#25572 = MCO Delta 2 r1           Dec 29 17:49     Dec 29 20:16 +-3h
#25572 = MCO Delta 2 r1           Dec 30 04:22     Dec 29 20:16 +-1h

#24670 = Cosmos 2335              Dec 29 22:33     Dec 31 22:54 +-1d

#25421 = Orbcomm 13 Pegasus r     Dec 29 07:47     Jan  4 22:25 +-4d

#25532 = Iridium 2 Delta r        Dec 30 18:20     Jan  6 17:52 +-4d

#25533 = Sputnik 41               Dec 28 07:25     Jan 10 10:38 +-8d

               -------------------------------

The final elset for #25572, the Mars Climate Orbiter Delta 2 rocket was:

Iridm 2 Delta r  5.9  2.4  0.0  5.6 d            317 x 206 km
1 25532U 98066F   98364.69815706  .01149445 -12527-5  10852-2 0  1146
2 25532  82.4466 253.5062 0083337 140.8065 220.1355 16.04743010  8530

This shows it 2.5 seconds early against the predicted orbital evolution 
I posted here yesterday. Incorporating this into my final SatEvo
analysis gives decay near a southbound equator crossing at December 9.84
(20:11 UTC) but with a possibility that it survived for another rev.
This is in good agreement with the predictions by SpaceCom and Harro
Zimmer. Surprisingly, the OIG status report says that this decayed on
the 30th.

               -------------------------------

Against yesterday's prediction, #24670, Cosmos 2335, was running almost 
19 seconds early at the epoch of latest elset for epoch 98364.59785206.
I now predict decay for December 31.87 (20:47 UTC +-6h).
Prediction:
Cosmos 2335      6.0  0.0  0.0  4.2 v            224 x 168 km
1 24670U 96069A   98365.02823787  .05865933  18249-1  10849-2 0 92009
2 24670  65.0027 277.3691 0042879 255.9377 103.5852 16.28827289116425
Cosmos 2335      6.0  0.0  0.0  4.2 v            207 x 162 km
1 24670U 96069A   98365.33487104  .08451891  43070-1  11076-2 0 92002
2 24670  65.0013 276.2047 0034179 255.7902 103.8299 16.33101407116475
Cosmos 2335      6.0  0.0  0.0  4.2 v            172 x 146 km
1 24670U 96069A   98365.70142992  .21736297  33521+0  71421-3 0 92006
2 24670  64.9982 274.8000 0019152 255.6124 104.1749 16.42588483116534
Cosmos 2335      6.0  0.0  0.0  4.2 v            144 x 131 km
1 24670U 96069A   98365.82296398  .58614139  32123+1  56272-3 0 92004
2 24670  64.9958 274.3283 0010045 255.5528 104.3357 16.50705219116550


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/