Decay watch: May 21 (Nimiq 1 Proton & platform)

Alan Pickup (alan@wingar.demon.co.uk)
Fri, 21 May 1999 20:52:21 +0100

SpaceCom has not yet identified the objects from the Nimiq 1 launch
or, for that matter, those from the TERRIERS/MUBLCOM launch some days
ago. I expect the following are correct, though...
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Object: #25741 = 99- 27 B = Nimiq 1 Proton r

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

SpaceCom   May 21 08:04     May 22 23:52 +-1d        43.9 S    73.5 W

SatEvo     May 21 19:45     May 22 23:43 +-7h        51.2 S   100.4 W

Latest elset:
Nimiq 1 Proton r                                 206 x 151 km
1 25741U 99027B   99141.66417230  .03569061  12239-4  25460-3 0    81
2 25741  51.6062 220.8844 0041960 272.8787  86.6719 16.35167735   124

SatEvo prediction:
Nimiq 1 Proton r                                 195 x 146 km
1 25741U 99027B   99142.03051415  .04743711  12772-1  20802-3 0 90082
2 25741  51.6053 218.8220 0037222 274.4206  85.1541 16.38254577   186
Nimiq 1 Proton r                                 185 x 142 km
1 25741U 99027B   99142.27432425  .05970140  22314-1  17869-3 0 90083
2 25741  51.6046 217.4439 0033391 275.4509  84.1682 16.40839763   224
Nimiq 1 Proton r                                 173 x 136 km
1 25741U 99027B   99142.51769765  .08350542  48265-1  15486-3 0 90087
2 25741  51.6036 216.0624 0028580 276.4839  83.1907 16.44248866   260
Nimiq 1 Proton r                                 154 x 127 km
1 25741U 99027B   99142.76045287  .15268579  18551+0  14051-3 0 90086
2 25741  51.6022 214.6761 0021352 277.5204  82.2369 16.49603256   309
Nimiq 1 Proton r                                 137 x 117 km
1 25741U 99027B   99142.88145522  .28319967  64469+0  14172-3 0 90087
2 25741  51.6009 213.9801 0015371 278.0410  81.7845 16.54548123   322
Nimiq 1 Proton r                                 123 x 109 km
1 25741U 99027B   99142.94178678  .48598637  23411+1  14588-3 0 90081
2 25741  51.5998 213.6307 0010779 278.3023  81.5754 16.58908064   332

Note: Near identical predictions by SpaceCom and SatEvo, though 
SpaceCom's was made much earlier. This is a morning object after it 
leaves eclipse near 48 deg N latitude at 02:30h local time. Eclipse
entry is near 51 deg S latitude in the evening.
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Object: #25742 = 99- 27 C = Nimiq 1 Proton platform

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

SpaceCom   May 21 08:23     May 21 14:52 +-4h        50.3 N   167.0 W
SpaceCom   May 21 13:30     May 21 14:58 +-2h        49.9 N   130.5 W
SpaceCom   May 21 14:27     May 21 14:15 +-7m        35.6 S    94.6 E

SatEvo     May 21 19:00     May 21 14:31 +-35m       13.1 N   135.2 E

Final elset:
Nimiq 1 Proton platform                          173 x 151 km
1 25742U 99027C   99141.48058839  .20211329  12287-4  93882-3 0    73
2 25742  51.5873 221.9190 0016918 238.0496 121.7234 16.41396766    90

Note: I put decay over the extreme W Pacific, just after a northbound
equator crossing over Indonesia. The small uncertainty in SpaceCom's
final report suggests that there are fixes on the following orbit, so 
a further elset may yet appear. SpaceCom puts decay slightly earlier
than SatEvo, over the SE Indian Ocean.
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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/