Decay watch: February 12

Alan Pickup (alan@wingar.demon.co.uk)
Fri, 12 Feb 1999 20:25:09 +0000

This is the first of an experimental restructured form of my "Decay
watch" notes. It brings together the SpaceCom decay notices, my own
SatEvo decay predictions, and the current OIG and SatEvo-predicted
elsets on an object-by-object basis.  Comments welcome...

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Object: #16187 = 85- 99 A = Molniya 1-65

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

SpaceCom   Feb 11 10:12     Feb 13 08:19 +-1d         61.6 S   135.3 E
SpaceCom   Feb 12 09:58     Feb 13 10:13 +-15h        61.7 S    98.6 E

SatEvo     Feb 11 20:15     Feb 13 11:53 +-9h         61 S      80   E
SatEvo     Feb 12 20:15     Feb 13 13:29 +-5h         61.7 S    56.9 E

Current elset:
Molniya 1-65                                     3143 x 77 km
1 16187U 85099A   99043.59408928  .05263536  13943-4  54111-4 0  2728
2 16187  61.6989 127.9857 1918910 262.3286 230.5576 12.16111357 98105

My SatEvo-predicted elsets based (as always) on an analysis using
several recent elsets:
Molniya 1-65                                     2666 x 80 km
1 16187U 85099A   99043.80097858 1.34069726  35250+0  14987-2 0 92720
2 16187  61.6660 127.4836 1668141 262.3949  78.4282 12.72205493 98130
Molniya 1-65                                     2134 x 80 km
1 16187U 85099A   99044.03153430 1.65990122  61853+0  16166-2 0 92721
2 16187  61.6316 126.8700 1371716 262.4773  81.7760 13.40700362 98168
Molniya 1-65                                     1541 x 79 km
1 16187U 85099A   99044.24966018 2.27507677  15038+1  17296-2 0 92726
2 16187  61.5932 126.2193 1016782 262.5664  85.7850 14.24594896 98193
Molniya 1-65                                     1064 x 77 km
1 16187U 85099A   99044.38735968 3.28440516  40242+1  18228-2 0 92720
2 16187  61.5672 125.7575 0710207 262.6307  89.2494 14.98753883 98219
Molniya 1-65                                     760 x 76 km
1 16187U 85099A   99044.45345744 4.64444546  11521+2  19481-2 0 92726
2 16187  61.5471 125.5145 0503216 262.6650  91.5906 15.49649659 98225
Molniya 1-65                                     270 x 75 km
1 16187U 85099A   99044.51716684 9.99999999  50000+2  21764-2 0 92720
2 16187  61.5252 125.2575 0149279 262.7016  95.5993 16.37546965 98233

Note: Beware - the latest, and several recent elsets for this have drag
terms which are much too low or are set at the ceiling value of
0.99999999. This makes my analysis just a bit more difficult. The latest
elset shows it running 87 seconds early against the prediction I posted
yesterday. It could easily decay one or two orbits earlier, near perigee
at 61 deg S.
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Object: #19771 = 89- 4 E = Gorizont 17 aux motor

Decay predictions:

Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Feb 11 15:15     Feb 15 11:49 +-18h        46.4 N    41.6 W
SpaceCom   Feb 12 04:41     Feb 15 05:01 +-2d         42.6 S   106.5 W

SatEvo     Feb 11 20:15     Feb 16.0 +-0.9d
SatEvo     Feb 12 20:50     Feb 15 11:29 +-15h        22 N     101 W

Current elset:
Gorizont 17 aux motor                            645 x 140 km
1 19771U 89004E   99043.51759435  .07531289  10011-4  75058-3 0  4861
2 19771  46.3705 211.0617 0373400  17.3604 343.9972 15.58339449162623

SatEvo prediction:
Gorizont 17 aux motor                            600 x 139 km
1 19771U 89004E   99044.02915005  .08280008  63011-2  72679-3 0 94867
2 19771  46.3681 208.1836 0342011  20.2396 341.0840 15.66358593162703
Gorizont 17 aux motor                            550 x 137 km
1 19771U 89004E   99044.53795381  .09429236  90782-2  71379-3 0 94866
2 19771  46.3655 205.2858 0307089  23.1389 338.2151 15.75333737162780
Gorizont 17 aux motor                            493 x 136 km
1 19771U 89004E   99045.04364794  .11162019  14483-1  70293-3 0 94866
2 19771  46.3626 202.3655 0267111  26.0609 335.2597 15.85677821162865

Note: The latest elset shows this to be 45 sec early on yesterday's
prediction, which gave too great a weight to a published elset with a
too-low perigee.
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Object: #13103 = 82- 6 C = OPS 2849 deb

Decay predictions:

Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Feb 12 13:04     Feb 19 10:40 +-4d        54.5 S    91.1 E

SatEvo     Feb 12 19:40     Feb 21.1 +-3d

Current elset:
OPS 2849 deb                                     268 x 259 km
1 13103U 82006C   99041.17710652  .00578256  15951-3  90767-3 0   345
2 13103  97.4709 222.8800 0006388 276.8846  83.1708 16.03951669 69686

No SatEvo elsets provided at present.

Note: A new addition to SpaceCom's list. Elsets for this were
declassified recently. According to the new 60d Decay Forecast, this has
a Radar Cross Section (RCS) of 1.03 m^2. Unfortunately, t0e latest elset
is more than two days old.
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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/