Decay watch: Apr 15 (Satcom Delta)

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 15 Apr 1999 21:12:36 +0100

The decay of the Satcom Delta has slipped a wee bit...
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Object: #14329 = 83- 94 B = Satcom 2R Delta 1 r

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

SpaceCom   Apr  8 20:00     Apr 15 16:32 +-4d        17.9 S     6.4 E
SpaceCom   Apr 11 21:32     Apr 15 20:46 +-2d         3.1 S   107.8 W
SpaceCom   Apr 12 23:35     Apr 15 22:16 +-2d         0.9 N   122.8 W
SpaceCom   Apr 13 22:29     Apr 15 21:10 +-1d        25.4 N    13.0 W
SpaceCom   Apr 14 22:18     Apr 15 22:35 +-15h       25.1 N    50.5 W
SpaceCom   Apr 15 18:22     Apr 16 00:21 +-6h        10.9 N     0.0 E

SatEvo     Apr  9 21:45     Apr 15 14:00 +-1.5d
SatEvo     Apr 11 19:55     Apr 15 15:15 +-1d
SatEvo     Apr 12 19:55     Apr 15 13:47 +-15h       23.9 N   117.7 E
SatEvo     Apr 13 19:45     Apr 15 20:57 +-15h       21.4 N    50.1 W
SatEvo     Apr 14 21:00     Apr 15 22:39 +-6h        23.3 N    15.2 W
SatEvo     Apr 15 19:40     Apr 15 00:28 +-2h         8.8 S    39.7 E

Latest elset:
Satcm2R Del 1 r  6.4  2.0  0.0  5.0 d            196 x 152 km
1 14329U 83094B   99105.62151738  .08192590  00000-0  62890-3 0   274
2 14329  25.4361  54.9091 0033809 109.8064 250.6610 16.36831201725770

SatEvo prediction for final revs:
Satcm2R Del 1 r  6.4  2.0  0.0  5.0 d            169 x 138 km
1 14329U 83094B   99105.86474763  .23086987  41551+0  48352-3 0 90276
2 14329  25.4349  52.9061 0023810 113.2195 247.0315 16.44559368725813
Satcm2R Del 1 r  6.4  2.0  0.0  5.0 d            158 x 132 km
1 14329U 83094B   99105.92534325  .34957119  10325+1  43707-3 0 90275
2 14329  25.4344  52.4030 0019609 114.0767 246.1285 16.47965491725822
Satcm2R Del 1 r  6.4  2.0  0.0  5.0 d            137 x 120 km
1 14329U 83094B   99105.98576949  .79695394  57870+1  42196-3 0 90279
2 14329  25.4336  51.8981 0012775 114.9371 245.1956 16.54113023725837

Note: The latest elset above shows it running 14 seconds late against 
yesterday's SatEvo prediction. I now predict decay about halfway 
around the final orbit above. That orbit takes it close to the Florida
Keys at 23:56 UTC, then over the Bahamas and the Atlantic. It crosses 
Africa from S Mauritania (00:14) to Dar Es Salaam, Tanzania, at 00:28
near my nominal decay point. If it survives, after crossing the 
Indian Ocean it overflies Australia from Carnarvon, W Australia, at
00:47 to Townsville, Queensland, at 00:54.
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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/