Decay watch update: December 29

Alan Pickup (alan@wingar.demon.co.uk)
Tue, 29 Dec 1998 17:53:03 +0000

Catching up after a couple of days away...

With the exception of that for #25532, the following SpaceCom decay 
notices were published since my last update on the 26th:

Object                            Notice issued    Predicted decay
                                       UTC              UTC
#25120 = Orbcomm 9 Pegasus r      Dec 27 14:34     Dec 28 14:58 +-18h
#25120 = Orbcomm 9 Pegasus r      Dec 28 03:19     Dec 28 15:37 +-8h
#25120 = Orbcomm 9 Pegasus r      Dec 28 09:18     Dec 28 14:50 +-4h
#25120 = Orbcomm 9 Pegasus r      Dec 28 12:30     Dec 28 14:44 +-2h
#25120 = Orbcomm 9 Pegasus r      Dec 28 18:24     Dec 28 14:44 +-2h

#23539 = Brazilsat B2 Spelda      Dec 27 04:11     Dec 29 04:35 +-1d
#23539 = Brazilsat B2 Spelda      Dec 27 21:45     Dec 28 22:12 +-18h
#23539 = Brazilsat B2 Spelda      Dec 28 16:43     Dec 29 04:21 +-7h
#23539 = Brazilsat B2 Spelda      Dec 28 20:59     Dec 29 03:12 +-5h
#23539 = Brazilsat B2 Spelda      Dec 29 01:40     Dec 29 03:07 +-5h
#23539 = Brazilsat B2 Spelda      Dec 29 05:19     Dec 29 03:07 +-5h
     
#25572 = MCO Delta 2 r1           Dec 26 22:29     Dec 29 16:55 +-2d
#25572 = MCO Delta 2 r1           Dec 27 20:53     Dec 29 19:36 +-1d
#25572 = MCO Delta 2 r1           Dec 28 21:29     Dec 29 21:59 +-15h
#25572 = MCO Delta 2 r1           Dec 29 08:22     Dec 29 20:43 +-8h
#25572 = MCO Delta 2 r1           Dec 29 14:17     Dec 29 20:14 +-4h

#24670 = Cosmos 2335              Dec 28 14:08     Jan  1 13:03 +-2d
#24670 = Cosmos 2335              Dec 29 07:27     Jan  1 04:38 +-2d

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

#25532 = Iridium 2 Delta r        Dec 25 10:47     Jan  6 08:19 +-7d

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


Using SatEvo, I put the decay of #25120, the Orbcomm 9 Pegasus rocket,
at December 28.60, near or shortly after a southbound equator crossing 
near 126 deg E longitude (over Indonesia) at 14:21 UTC. The track 
would have continued over eastern Australia towards the North Island 
of New zealand at 14:36 UTC. The final OIG/SpaceCom analysis (above) 
puts decay some 1,500 km beyond New Zealand at 43.5 deg S, 167.2 deg W.


I calculate that the Brazilsat B2 Spelda (#23539) decayed today at 
December 29.12, near a northbound equator crossing at 02:53 UTC near 
64 deg W. Again the SpaceCom conclusion is very similar.


#25572, the Mars Climate Orbiter Delta 2 rocket, is close to decay and
may do so at about December 29.89, 21:24 UTC +-90 minutes by my SatEvo
calculation. This puts it ENE-bound at about 20 deg N, 110 deg E after 
crossing Vietnam. Predicted elsets for the final revs:
MCO Delta 2 r1   5.9  2.4  0.0  5.0 d            233 x 131 km
1 25572U 98073B   98363.68911367  .23968419  25318+0  57355-3 0 90783
2 25572  23.8761  46.9122 0077805 115.7802 245.0244 16.33968136  2789
MCO Delta 2 r1   5.9  2.4  0.0  5.0 d            216 x 130 km
1 25572U 98073B   98363.75008410  .30046258  45649+0  62722-3 0 90786
2 25572  23.8757  46.4073 0065527 116.6585 244.0138 16.37224708  2796
MCO Delta 2 r1   5.9  2.4  0.0  5.0 d            195 x 129 km
1 25572U 98073B   98363.81091079  .43695711  12019+1  71045-3 0 90788
2 25572  23.8750  45.9008 0050374 117.5393 242.9733 16.41574222  2806
MCO Delta 2 r1   5.9  2.4  0.0  5.0 d            159 x 123 km
1 25572U 98073B   98363.87151680 1.06586532  10125+2  89839-3 0 90786
2 25572  23.8740  45.3922 0028000 118.4240 241.8585 16.49323521  2812


Cosmos 2335 seems to have interrupted its powered descent on the 
morning of December 27. There is still something not-quite-right about 
the elsets since then, and I am not fully certain whether it is still
being manoeuvred in a small way. If it behaves itself, it may decay
at about December 31.9 my my current calculation. Prediction:
Cosmos 2335      6.0  0.0  0.0  4.2 v            257 x 182 km
1 24670U 96069A   98364.04309340  .03097571  40415-2  11126-2 0 91938
2 24670  65.0095 281.0654 0057011 258.7105 100.6483 16.20070350116266
Cosmos 2335      6.0  0.0  0.0  4.2 v            243 x 178 km
1 24670U 96069A   98364.53645536  .03882888  69646-2  11253-2 0 91933
2 24670  65.0083 279.2167 0049074 258.4751 100.9736 16.23478919116344
Cosmos 2335      6.0  0.0  0.0  4.2 v            224 x 172 km
1 24670U 96069A   98365.02864194  .05411029  15677-1  11409-2 0 91935
2 24670  65.0069 277.3619 0039600 258.2392 101.3165 16.27954074116427


Other updated SatEvo predictions are:

   #    Designation    Name               Predicted decay

 25421   98- 46 J   Orbcomm 13 Pegasus r   January  5.1 +-1.5d
  4583   70- 85 A   Meteor 1-6             January  6.1 +-1.5d
 25532   98- 66 F   Iridium 2 Delta r      January  6.5 +-1.5d
 21148   91- 17 B   Lacrosse 2 r           January  8.0 +-2d
 25533   98- 62 C   Sputnik 41             January  9.1 +-2d
 25579   98- 74 C   Iridium 11A CZ-2C r    January 17   +-4d

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/