Decay watch: Apr 30

Alan Pickup (alan@wingar.demon.co.uk)
Fri, 30 Apr 1999 20:53:55 +0100

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Object: #12519 = 81- 54 E = Molniya 3-16 r2

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

SpaceCom   Apr 22 12:05     Apr 29 12:41 +-1d         8.6 S    56.3 E
SpaceCom   Apr 26 13:27     Apr 30 09:35 +-2d         6.3 S   101.1 E
SpaceCom   Apr 27 07:48     Apr 30 07:49 +-2d        36.9 S   106.7 E
SpaceCom   Apr 28 11:01     Apr 30 06:16 +-1d        41.1 S   126.0 E
SpaceCom   Apr 29 06:25     Apr 30 06:49 +-15h       58.5 N   153.8 W
SpaceCom   Apr 29 15:24     Apr 30 03:25 +-2h        12.7 S   169.6 W
SpaceCom   Apr 29 21:37     Apr 30 03:27 +-4h         4.8 S   165.9 W
SpaceCom   Apr 30 01:36     Apr 30 03:25 +-2h        13.9 S   170.3 W
SpaceCom   Apr 30 03:28     Apr 30 03:21 +-33m       25.2 S   176.4 W

SatEvo     Apr 23 20:45     May  1 04:00 +-2d
SatEvo     Apr 26 18:30     May  1 19:04 +-1.3d      40.4 S    73.4 W
SatEvo     Apr 27 20:00     May  1 03:29 +-1d        41.6 S   162.2 E
SatEvo     Apr 28 20:45     May  1 00:27 +-16h       40.6 S   150.6 W
SatEvo     Apr 29 06:45     Apr 30 15:15 +-10h       41.8 S    12.1 W
SatEvo     Apr 29 19:35     Apr 30 09:12 +-6h        40.9 S    81.0 E
SatEvo     Apr 29 22:35     Apr 30 04:42 +-2h        42.8 S   147.4 E
SatEvo     Apr 30 18:30     Apr 30 03:12 +-30m       45.4 S   167.0 E

Final elset:
Molniya 3-16 r2                                  431 x 99 km
1 12519U 81054E   99119.91311007  .70177935  11432-4  67532-3 0  8187
2 12519  61.8478 106.1893 0249786 308.0587 150.2174 16.03473185100389

Note: This is one that SpaceCom got correct and SatEvo came second :(
This was an almost unique test for SatEvo, and it clearly needs more 
tuning to cope with deep perigee decayers like this.
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Object: #388 = 62- 39 D = FTV 3502 Scout r

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

SpaceCom   Apr 27 00:20     May  3 18:06 +-4d        65.6 N   171.1 W
SpaceCom   Apr 29 06:46     May  3 01:51 +-2d        79.5 N    38.4 E
SpaceCom   Apr 29 22:12     May  2 22:42 +-2d        36.1 N   132.5 E

SatEvo     Apr 27 19:45     May  4 00:00 +-2d
SatEvo     Apr 29 19:50     May  3 11:00 +-1d
SatEvo     Apr 30 19:05     May  3 01:27 +-18h
Latest elset:
FTV3502 Scout r  1.5  0.5  0.0  6.5 d            229 x 223 km
1 00388U 62039D   99120.47814531  .02229213  69922-2  16275-2 0  7052
2 00388  98.5326 335.1576 0004583 280.0677  80.0132 16.17526201974065

SatEvo predictions:
FTV3502 Scout r  1.5  0.5  0.0  6.5 d            221 x 216 km
1 00388U 62039D   99121.03444896  .02913030  41460-2  15092-2 0 97057
2 00388  98.5316 335.8865 0004150 277.8818  82.0711 16.20355248974153
FTV3502 Scout r  1.5  0.5  0.0  6.5 d            212 x 207 km
1 00388U 62039D   99121.52802981  .03696644  62053-2  14841-2 0 97056
2 00388  98.5304 336.5359 0003702 275.9336  84.0242 16.23589212974235
FTV3502 Scout r  1.5  0.5  0.0  6.5 d            201 x 196 km
1 00388U 62039D   99122.02049474  .05006895  13675-1  14085-2 0 97052
2 00388  98.5289 337.1872 0003169 273.9796  85.9842 16.27793523974310

Note: In future, and to avoid wasting (even more of) my time I propose 
to estimate the SatEvo-predicted decay latitudes and longitudes only 
during the final hours before a decay. I will still report SpaceCom's 
estimates. FWIW, today's GSFC 60-Day Decay Forecast predicts the decay
of this on Apr 30 (!)
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Object: #8755 = 76- 24 B = Cosmos 808 r

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

SatEvo     Apr 28 21:00     May  9 19:00 +-3d
SatEvo     Apr 30 19:10     May  7 23:00 +-2d

Latest elset:
Cosmos 808 r     3.8  2.6  0.0  5.1 v            240 x 230 km
1 08755U 76024B   99120.13369010  .00731020  31506-3  58923-3 0  2431
2 08755  81.2111 143.0262 0007400 173.6169 186.5436 16.14322382276485

Note: The 60-Day DF has this decaying on May 1.
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Object: #22583 = 93- 17 C = GPS 2-19 r1

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

SatEvo     Apr 30 19:15     May  4 21:00 +-2d

Latest elset:
GPS 2-19 r1      5.9  2.4  0.0  5.0 v            278 x 207 km
1 22583U 93017C   99120.48566958  .01503945  26340-5  10624-2 0  7677
2 22583  36.1419 106.5819 0054052 134.2160 226.3110 16.11573528328264

Note: Another decayer for May 1, according to the 60-Day DF.
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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/