Decay watch: February 10
Alan Pickup (alan@wingar.demon.co.uk)
Wed, 10 Feb 1999 22:39:03 +0000
Today's SpaceCom decay notices:
Object Notice issued Predicted decay
UTC UTC
#22584 = GPS 2-19 r2 Feb 10 01:27 Feb 10 13:54 +-15h
#22584 = GPS 2-19 r2 Feb 10 08:22 Feb 10 14:43 +-4h
#22584 = GPS 2-19 r2 Feb 10 12:38 Feb 10 15:06 +-2h
#22584 = GPS 2-19 r2 Feb 10 19:12 Feb 10 14:45 +-13m
#16187 = Molniya 1-65 Feb 10 20:45 Feb 13 15:50 +-2d
#19771 = Gorizont 17 aux motor Feb 8 08:28 Feb 14 23:14 +-4d
-------------------------------
The final elset for the GPS 2-19 PAM-D rocket ...
GPS 2-19 r2 3.0 1.5 0.0 6.5 d 226 x 119 km
1 22584U 93017D 99041.54405435 .68433681 93542-6 81510-3 0 2173
2 22584 34.4372 121.2033 0082116 73.7274 287.2365 16.37555284136599
... shows it running 16 seconds late on the SatEvo prediction I posted
here yesterday. Earlier elsets today were also close to SatEvo's
prediction and I'd be quite happy to stick with my yesterday's
prediction of decay at 15:10 UTC. However, SpaceCom has declared an
unusually small uncertainty of 13 minutes in their decay time of 14:45
UTC. I note that if it had survived another 14 minutes it would have
passed 500 km SW of Los Angeles, so I surmise that its non-detection on
that pass fixes the end of their decay window. Perigee occurred at 14:48
UTC and, given its eccentricity and its sighting on the previous orbit
(as evidenced by the above elset) I agree with SpaceCom that a decay
prior to 14:32 UTC is unlikely.
-------------------------------
The latest elsets for the other two decayers are:
Molniya 1-65 6447 x 72 km
1 16187U 85099A 99041.74370074 .58180951 00000-0 77268-3 0 2543
2 16187 61.6223 131.3538 3306896 262.0876 59.9062 9.17634255 97914
Gorizont 17 aux motor 788 x 141 km
1 19771U 89004E 99041.57802645 .05461783 93217-5 68509-3 0 4746
2 19771 46.3804 221.7150 0472734 6.6611 354.0268 15.33787015162329
The Molniya's elset (above) has it running 2.7 minutes early against the
predictions I posted here yesterday. My latest analysis still shows
decay at February 13.50, now +-0.6 day, and leads to this SatEvo
prediction:
Molniya 1-65 5925 x 76 km
1 16187U 85099A 99042.06476980 .63583411 62918-1 98502-3 0 92546
2 16187 61.6219 130.8868 3118413 262.1512 61.8855 9.55887232 97945
Molniya 1-65 5579 x 76 km
1 16187U 85099A 99042.27151849 .67731510 71152-1 99707-3 0 92540
2 16187 61.6217 130.5677 2988807 262.1947 63.3384 9.83018264 97969
Molniya 1-65 5065 x 76 km
1 16187U 85099A 99042.57095656 .74825393 87449-1 10180-2 0 92540
2 16187 61.6213 130.0767 2787618 262.2616 65.5966 10.25632286 97998
Molniya 1-65 4726 x 76 km
1 16187U 85099A 99042.76361112 .80280304 10220+0 10341-2 0 92548
2 16187 61.6210 129.7405 2648325 262.3074 67.1625 10.55487876 98019
The predicted decay of #19771, the aux motor, has slipped to February
16.0 +-1.1 day according to my current analysis.
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/