Decay watch update: New Year's Day

Alan Pickup (alan@wingar.demon.co.uk)
Fri, 1 Jan 1999 18:17:55 +0000

These SpaceCom decay notices are current or have been issued and 
superseded since my update yesterday:

Object                            Notice issued    Predicted decay
                                       UTC              UTC
     
#25603 = C 2362 Proton deb L      Dec 31 18:02     Jan  1 01:54 +-6h

#25602 = C 2362 Proton deb K      Dec 31 18:02     Jan  1 03:39 +-7h

#24670 = Cosmos 2335              Dec 31 19:57     Jan  1 02:26 +-5h
#24670 = Cosmos 2335              Jan  1 00:47     Jan  1 02:55 +-2h
#24670 = Cosmos 2335              Jan  1 05:42     Jan  1 04:33 +-37m

#25421 = Orbcomm 13 Pegasus r     Dec 31 22:40     Jan  4 21:01 +-2d

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

 #4583 = Meteor 1-6               Jan  1 08:08     Jan  8 07:57 +-4d

#25533 = Sputnik 41               Dec 30 20:36     Jan  9 21:00 +-6d

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

It seems we were all caught out by the longevity of Cosmos 2335. My 
final (clearly inebriated!) SatEvo prediction (made 8 hours earlier) 
had decay forecast for December 31.99 (23:50 UTC +-2h). Re-entry, 
if SpaceCom is correct, came at January 1 04:33 UTC +-37 minutes. 
The final (highest-numbered) elset, one of three issued for the nodal 
crossing, was:

Cosmos 2335      6.0  0.0  0.0  4.2 v            118 x 107 km
1 24670U 96069A   99001.12741337  .99999999  78494-5  33829-3 0  2154
2 24670  65.0141 273.1274 0008319 249.2722 110.5261 16.60290174116609

This epoch corresponds to 03:03 UTC and I think it unlikely that Cosmos
2335 could have lasted for the additional 90 minutes, more than one
orbit, implied by SpaceCom's final decay notice. My own analysis implies 
decay at January 1.146 03:30 UTC.

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

Four of the debris objects from the Cosmos 2362/3/4 launch are rapid 
decayers, and three have probably decayed today, January 1. These are
the two mentioned above, the K and L objects, plus #25591 = 1998- 77 M. 
There are too few elsets for these to be sure of the decay times, but 
the times given above for K and L look reasonable. M may have decayed 
at about January 1.6. The fourth object, #25599 = 1998- 77 G, may
survive until the 2nd.


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/