Re: Decay Watch: Molniya 3-16

Alan Pickup (alan@wingar.demon.co.uk)
Thu, 29 Jan 1998 08:24:24 +0000

In message <3.0.2.32.19980128232402.00698294@pcisys.net>, Ron Lee
<ronlee@pcisys.net> writes
>I just looked for it at 06:12 UT on 29 Jan.  Missed it even though 
>looking +/- 5 minutes.  I ran Satevo with the elset and came up with
>the following for 29.5 UT:
>
>Molniya 3-16                                     20645 x 111 km
>1 12512U 81054A   98029.50457832  .09822878  25698-2  37252-2 0 90471
>2 12512  61.9706  91.5285 6127116 272.6190  23.2120  4.00289491123613
>

This may be currently lost by USSpaceCom, but I expect they with recover
it before re-entry (February 3??).

I've tried several fits to recent elsets, none of them ultra-convincing.
SatEvo is just not cut out to handle objects in which the luni-solar
induced perigee decline is the driving factor. Over short spells, I find
that reducing its "Q" factor gives a somewhat better fit, and the
following prediction uses a Q factor of 0.5. I'm sure the perigee height
(100 km) below is too high - it is probably closer to 80 km.

Molniya 3-16                                     21094 x 100 km
1 12512U 81054A   98028.99585374  .10805435  55849-2  26429-2 0 90417
2 12512  61.7476  91.6818 6183541 272.6339  22.7170  3.92562432123592
Molniya 3-16                                     20776 x 100 km
1 12512U 81054A   98029.24901901  .11245053  60097-2  26875-2 0 90415
2 12512  61.7177  91.5791 6147454 272.6471  23.0229  3.98143474123607
Molniya 3-16                                     20458 x 100 km
1 12512U 81054A   98029.49861995  .11712229  64837-2  27343-2 0 90411
2 12512  61.6870  91.4757 6110587 272.6606  23.3364  4.03872160123616
Molniya 3-16                                     20138 x 100 km
1 12512U 81054A   98029.74466428  .12209397  70146-2  27834-2 0 90414
2 12512  61.6555  91.3718 6072901 272.6744  23.6580  4.09756364123629
Molniya 3-16                                     19817 x 100 km
1 12512U 81054A   98029.98715854  .12739309  75866-2  28352-2 0 90411
2 12512  61.6257  91.2673 6034351 272.6885  23.9881  4.15804590123630
Molniya 3-16                                     19495 x 100 km
1 12512U 81054A   98030.22610798  .13299170  75861-2  28885-2 0 90415
2 12512  61.5950  91.1622 5994893 272.7029  24.3272  4.22025861123642
Molniya 3-16                                     19173 x 100 km
1 12512U 81054A   98030.46151900  .13855922  82015-2  29361-2 0 90418
2 12512  61.5661  91.0564 5954560 272.7176  24.6751  4.28416726123651

Note that this shows it more than 8 minutes earlier than Ron's
prediction at the equator crossing around 98029.5. Other evolutions also
bring it around earlier than Ron's prediction, and I wouldn't be
surprised it it was earlier still.

Alan
-- 
 Alan Pickup | COSPAR site 2707:   55d53m48.7s N   3d11m51.2s W    156m asl
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