Decay watch: May 28
Alan Pickup (alan@wingar.demon.co.uk)
Fri, 28 May 1999 22:52:07 +0100
SpaceCom has issued another decay notice for the Titan, but are still
keeping the elsets secret.
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Object: #25745 = 99- 28 B = USA 144 Titan 4 r
Decay predictions:
Source Prediction made Predicted decay at Latitude Longitude
UTC UTC deg deg
SpaceCom May 24 21:58 Jun 2 11:36 +-5d 63.4 S 94.0 W
SpaceCom May 26 06:28 Jun 1 14:00 +-4d 47.1 N 3.3 W
SpaceCom May 28 11:26 Jun 1 11:29 +-2d 19.2 N 172.6 E
SatEvo May 25 12:00 Jun 3 +-3d
SatEvo May 27 19:00 Jun 1 23:00 +-1.4d (but see note below)
SatEvo May 29 21:25 Jun 1 02:43 +-20h
Latest elset by Pierre Neirinck:
USA 144 Titan 4 r 261 x 194 km
1 25745U 99028 B 99147.90363690 .01450000 00000-0 72065-3 0 03
2 25745 63.3550 81.6250 0050747 168.9210 191.1912 16.17077649 01
SatEvo prediction:
USA 144 Titan 4 r 247 x 188 km
1 25745U 99028 B 99149.07725070 .01876379 16497-2 71594-3 0 90002
2 25745 63.3537 76.9751 0044703 168.9502 191.1483 16.20929681 197
USA 144 Titan 4 r 240 x 185 km
1 25745U 99028 B 99149.50887436 .02119384 21362-2 71360-3 0 90000
2 25745 63.3532 75.2580 0042111 168.9611 191.1316 16.22650017 265
USA 144 Titan 4 r 231 x 180 km
1 25745U 99028 B 99150.06309263 .02561770 33063-2 70901-3 0 90001
2 25745 63.3523 73.0463 0038333 168.9753 191.1090 16.25226423 351
Note: Pierre comments that the elset posted yesterday by Rainer, and
copied in my previous note, contained an average drag value for the
period of the analysis, rather than the instantaneous value for the
epoch. The latter is estimated by Pierre as 0.0125 rather than the
0.01096472 as posted. Using this value of drag, my prediction yesterday
for decay on June 1 at 23:00 UTC would have jumped forwards to June 1
at 05:00. The drag value in Pierre's latest elset is his (new)
instantaneous value - the average value over the period of analysis is
0.01228, in agreement with Rainer's posting today. Again, the SatEvo
prediction is based entirely on Pierre's elset.
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Object: #25683 = 99- 20 B = Landsat 7 Delta r
Decay predictions:
Source Prediction made Predicted decay at Latitude Longitude
UTC UTC deg deg
SpaceCom May 26 20:46 May 30 20:26 +-2d 25.7 S 102.5 W
SpaceCom May 28 19:51 May 30 17:37 +-1d 52.4 S 75.7 W
SatEvo May 25 19:30 Jun 1 00:00 +-1.2d
SatEvo May 26 18:00 May 31 10:00 +-1d
SatEvo May 27 18:00 May 31 09:00 +-0.8d
SatEvo May 28 21:40 May 31 03:50 +-12h
Latest elset:
Lndst7 Delta r 5.9 2.4 0.0 5.0 d 301 x 144 km
1 25683U 99020B 99148.78883613 .03311436 92313-5 24227-3 0 1311
2 25683 107.5582 274.1139 0118401 242.5428 116.4437 16.18884472 6745
SatEvo prediction:
Lndst7 Delta r 5.9 2.4 0.0 5.0 d 292 x 144 km
1 25683U 99020B 99149.03586157 .03770575 37045-2 25017-3 0 91311
2 25683 107.5576 274.7731 0112487 241.9474 116.9105 16.20701072 6782
Lndst7 Delta r 5.9 2.4 0.0 5.0 d 272 x 141 km
1 25683U 99020B 99149.52910790 .04456379 58402-2 23672-3 0 91318
2 25683 107.5561 276.0947 0099422 240.7535 118.2487 16.24733741 6867
Lndst7 Delta r 5.9 2.4 0.0 5.0 d 249 x 138 km
1 25683U 99020B 99150.02101606 .05646273 11290-1 22263-3 0 91316
2 25683 107.5544 277.4209 0084167 239.5551 119.6108 16.29636540 6946
Note: The latest elset has this running 17 seconds early against my
previous prediction.
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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/