Decay watch update: December 17

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 17 Dec 1998 21:09:24 +0000

OIG have the published the following decay notices for the Centaur
rocket since my update yesterday:

Object                            Notice issued    Predicted decay
                                       UTC              UTC
#22928 = Telstar 401 Centaur r    Dec 16 19:44     Dec 17 08:07 +-12h
                                  Dec 17 01:38     Dec 17 08:02 +-12h
                                  Dec 17 05:53     Dec 17 07:50 +-12h
                                  Dec 17 08:36     Dec 17 07:50 +-12h

No further elsets were issued meantime, so perhaps the small change in
the predicted decay time, with no improvement in the width of the decay
window, may be due to the use of updated atmospheric density information
derived from other tracking data.

The final OIG analysis of decay at 07:50 UTC +-12h is only a few minutes
later than my final one for 07:28 UTC +- 6h, reported yesterday. As
Harro says, it might have dropped several hours earlier.

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

The following OIG decay notices have yet to be superseded:

Object                            Notice issued    Predicted decay
                                       UTC              UTC
#25120 = Orbcomm 9 Pegasus r      Dec 16 10:38     Dec 29 11:40 +-8d
#25499 = C 2350 aux motor         Dec 16 17:30     Dec 18 16:28 +-1d

The latest elsets for these are:

Orbc9 Pegasus r  1.3  1.0  0.0  7.0 d            332 x 224 km
1 25120U 97084J   98351.41194369  .00632318  00000-0  87297-3 0  3893
2 25120  44.9534 327.7245 0080638 104.1713 256.8746 15.98772952 55422
C 2350 Prot deb (aux motor)                      4616 x 105 km
1 25499U 98025E   98351.28298727  .56425918  19186-4  29959-2 0  1171
2 25499  47.2009 212.1832 2581346  78.6249  43.0313 10.62818962  5762

I still predict the decay of the Orbcomm 9 Pegasus rocket for December
28 +-3 days. I now predict the re-entry of the auxiliary motor from the
Cosmos 2350 launch at December 19.2 +-0.5 day. Re-entry is most likely
soon after perigee which will occur just before northern apex, its most
northerly point at 47 deg N. Given that the above elset for this is
already 14 hours old, predicted elsets are probably too uncertain to
quote here.

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/