Decay watch: June 28

Alan Pickup (alan@wingar.demon.co.uk)
Mon, 28 Jun 1999 21:00:20 +0100

Solar activity is now at a very high level, higher than at any time
during the current solar cycle. The SESC sunspot number for the 27th
was 341, while the 10.7 cm radio flux stood at 207 in the usual units,
suggesting that drag rates should be high too. Meantime, the decaying
Molniya r2 was denied a second reprieve...
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Object: #16686 = 86- 31 D = Molniya 3-28 r2

Decay predictions:
Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Jun 17 01:00     Jun 23 16:44 +-4d        46.6 S    44.7 W
SpaceCom   Jun 20 05:29     Jun 24 05:35 +-2d        27.7 S   139.1 E
SpaceCom   Jun 21 01:35     Jun 24 05:27 +-2d        56.8 S   102.6 E
SpaceCom   Jun 21 08:42     Jun 24 05:17 +-2d        60.9 S    53.9 E
SpaceCom   Jun 22 16:51     Jun 24 07:40 +-1d        47.4 S    88.3 E
SpaceCom   Jun 23 05:19     Jun 24 05:39 +-15h       60.2 S    84.8 E
SpaceCom   Jun 23 05:19     Jun 24 05:39 +-15h       60.2 S    84.8 E
SpaceCom   Jun 23 21:52     Jun 24 05:55 +-5h        56.8 S    95.8 E
SpaceCom   Jun 27 10:44     Jun 28 10:48 +-5h        35.4 S    36.4 E
SpaceCom   Jun 28 04:46     Jun 28 10:50 +-4h        28.1 S    41.7 E
SpaceCom   Jun 28 08:48     Jun 28 10:20 +-1h        26.1 S    98.8 W
SpaceCom   Jun 28 14:57     Jun 28 10:20 +-1h        26.1 S    98.8 W

SatEvo     Jun 17 19:35     Jun 24 00:00 +-2d
SatEvo     Jun 20 17:30     Jun 24 09:52 +-1.3d
SatEvo     Jun 21 20:20     Jun 24 05:27 +-18h
SatEvo     Jun 22 19:55     Jun 24 05:31 +-11h
SatEvo     Jun 23 18:40     Jun 24 07:34 +-5h        61.3 S    22.8 E
SatEvo     Jun 24 19:15     Jun 27 20:00 +-?
SatEvo     Jun 25 22:30     Jun 28 11:55 +-20h
SatEvo     Jun 26 19:00     Jun 28 13:39 +-14h
SatEvo     Jun 27 18:45     Jun 28 12:01 +-6h        61.6 S    59.2 W
SatEvo     Jun 28 18:40     Jun 28 10:32 +-25m       61.8 S    24.2 W

Final elset:
Moln 3-28 r2                                     313 x 78 km
1 16686U 86031D   99179.35395817  .99999999  91673-5  33605-3 0  5462
2 16686  61.7302 136.6770 0179350 268.4519 217.6436 16.28938049 85729

Note: The final elset has it running 43 seconds early against the
prediction I posted here yesterday. I estimate that this decayed
near perigee on the above orbit, near its southernmost point over
the far S Atlantic. SpaceCom put it a bit earlier on the rev, while 
southbound over the SE Pacific.
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Object: #25670 = 99- 17 B = DSP 19 Titan 4 r

Decay predictions:
Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Jun 27 10:54     Jul  1 10:37 +-19h       22.2 S   171.6 W
SpaceCom   Jun 28 17:18     Jul  1 15:31 +-2d         4.7 S   123.7 W

SatEvo     Jun 27 18:50     Jul  2 09:07 +-1d
SatEvo     Jun 28 19:45     Jul  2 04:38 +-16h

Latest elset (7 sec early against yesterday's prediction):
DSP 19 Titan4r  10.0  2.5  0.0  3.0 d 31         283 x 154 km
1 25670U 99017B   99179.64841814  .02010182 -73587-5  30750-3 0  1470
2 25670  28.6212  60.2637 0097263 289.6923  69.3193 16.20456219 12531

SatEvo prediction:
DSP 19 Titan4r  10.0  2.5  0.0  3.0 d 31         275 x 152 km
1 25670U 99017B   99180.01768384  .02364182  17590-2  32337-3 0 91475
2 25670  28.6209  57.3872 0092872 294.3665  64.6670 16.22196717 12592
DSP 19 Titan4r  10.0  2.5  0.0  3.0 d 31         252 x 147 km
1 25670U 99017B   99181.00037210  .03101765  35328-2  24325-3 0 91476
2 25670  28.6199  49.6951 0079765 306.8656  52.4058 16.27483604 12759
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Alan

-- 
 Alan Pickup | COSPAR 2707:  55d53m48.7s N  3d11m51.2s W   156m asl
 Edinburgh   | Tel: +44 (0)131 477 9144     Fax: +44 (0)870 0520750
 Scotland    | SatEvo page:   http://www.wingar.demon.co.uk/satevo/