Decay watch: June 23

Alan Pickup (alan@wingar.demon.co.uk)
Wed, 23 Jun 1999 20:02:29 +0100

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Object: #23558 = 86- 17 JE = GFZ 1

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

SpaceCom   Jun 17 00:38     Jun 23 13:22 +-4d        47.6 S     5.3 W
SpaceCom   Jun 19 15:53     Jun 23 15:21 +-2d        14.9 N    96.6 E
SpaceCom   Jun 20 18:00     Jun 23 13:52 +-2d        10.0 N   115.1 E
SpaceCom   Jun 21 17:40     Jun 23 14:14 +-1d        50.7 N   152.9 W
SpaceCom   Jun 22 06:57     Jun 23 02:10 +-12h        1.3 S    75.0 W
SpaceCom   Jun 22 13:51     Jun 23 00:53 +-7h        30.8 N    26.2 W
SpaceCom   Jun 22 18:42     Jun 22 23:52 +-6h        25.6 N   119.1 E
SpaceCom   Jun 23 01:27     Jun 23 03:38 +-8h         1.7 N    95.0 W
SpaceCom   Jun 23 05:29     Jun 23 03:38 +-8h         1.7 N    95.0 W

SatEvo     Jun 17 19:30     Jun 23 18:00 +-1.3d
SatEvo     Jun 20 17:15     Jun 23 16:44 +-16h
SatEvo     Jun 21 20:00     Jun 23 15:59 +-10h
SatEvo     Jun 22 19:25     Jun 23 00:41 +-3h         0.0      51.9 W
SatEvo     Jun 23 18:20     Jun 23 02:08 +-3h         0.0      74.1 W

Final elset:
GFZ 1            0.3  0.0  0.0 11.0 d            153 x 145 km
1 23558U 86017JE  99173.54432378  .04702966  12612-4  10413-3 0  7754
2 23558  51.6200 231.9360 0006075 300.2980  59.6781 16.46260097763208

Note: SpaceCom appears to have lost this well before its decay. The 
final elset is for the same rev as yesterday's "latest" elset but 
suggests that the equator crossing came one second later.
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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

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

Latest elset (7.3 min late against yesterday's prediction):
Moln 3-28 r2                                     2255 x 77 km
1 16686U 86031D   99174.69855183  .99999999  12127-4  11106-2 0  5031
2 16686  61.7686 152.5292 1443212 262.0427  81.5548 13.24858445 85041

SatEvo prediction:
Moln 3-28 r2                                     1815 x 76 km
1 16686U 86031D   99174.92081488 1.55996348  63781+0  10685-2 0 95031
2 16686  61.7401 151.8954 1187436 262.1229  84.2639 13.85254624 85077
Moln 3-28 r2                                     1480 x 75 km
1 16686U 86031D   99175.06322195 1.91710515  11163+1  10899-2 0 95035
2 16686  61.7197 151.4540 0982214 262.1796  86.5750 14.34290090 85094
Moln 3-28 r2                                     1091 x 73 km
1 16686U 86031D   99175.20045012 2.62166313  27577+1  11245-2 0 95033
2 16686  61.6944 150.9932 0731270 262.2395  89.4029 14.95167339 85112
Moln 3-28 r2                                     854 x 72 km
1 16686U 86031D   99175.26683240 3.38740314  53339+1  11662-2 0 95031
2 16686  61.6829 150.7533 0571492 262.2711  91.2058 15.34441013 85121
Moln 3-28 r2                                     541 x 70 km
1 16686U 86031D   99175.33139780 5.55357324  25412+2  13003-2 0 95033
2 16686  61.6618 150.5040 0352702 262.3042  93.6771 15.88842458 85133

Note: I judge that decay is most likely near the perigee point of
the penultimate predicted orbit above. It is possible it may survive 
into the next orbit and even until the following perigee. With the
period and apogee height changing so rapidly, it could be several 
minutes early or late and several degrees off track.
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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/