Decay watch: Iridium 19 Delta 2 rocket (and others)
Alan Pickup (alan@wingar.demon.co.uk)
Wed, 15 Apr 1998 19:55:51 +0100
The current published elset for the Iridium 19 Delta 2 rocket is:
Iridm 19 Delta r 5.9 2.4 0.0 5.6 d 231 x 186 km
1 24970U 97056F 98105.64081303 .02234011 -13263-5 74239-3 0 2701
2 24970 83.5881 265.4891 0034772 285.9210 73.8285 16.24102168 31471
This has it 143 seconds late on the predicted evolution I posted two
days ago. The drag it meets has climbed more slowly than I expected,
possibly because the atmosphere has been settling down as solar activity
has subsided from its remarkably high level of a week ago. On the 9th,
for example, the SESC sunspot number approached 200 - a level typical of
a strong sunspot maximum.
Not surprisingly, my predicted decay date has slipped and now stands at
April 17.8 +-0.4d. Predicted elsets:
Iridm 19 Delta r 5.9 2.4 0.0 5.6 d 224 x 182 km
1 24970U 97056F 98106.01024888 .02880543 44389-2 81666-3 0 92705
2 24970 83.5874 265.1214 0031610 284.3775 75.2716 16.26191884 31533
Iridm 19 Delta r 5.9 2.4 0.0 5.6 d 212 x 177 km
1 24970U 97056F 98106.50209041 .03773095 82690-2 82413-3 0 92707
2 24970 83.5862 264.6300 0026828 282.3152 77.3846 16.29419796 31616
Iridm 19 Delta r 5.9 2.4 0.0 5.6 d 193 x 167 km
1 24970U 97056F 98107.05402990 .06089158 24065-1 82963-3 0 92700
2 24970 83.5844 264.0752 0020153 279.9873 79.7853 16.34637514 31708
Iridm 19 Delta r 5.9 2.4 0.0 5.6 d 163 x 148 km
1 24970U 97056F 98107.54265231 .15514578 17928+0 51001-3 0 92705
2 24970 83.5812 263.5792 0011336 277.9069 81.9645 16.43754236 31782
The Iridium 51 Long March (CZ-2C) rocket is now predicted to re-enter on
April 24. Joining the mass-suicide of Iridium rockets is the Iridium 43
Delta 2 rocket which I now expect to decay about April 25. The latter
enters the Earth's shadow near latitude 56 deg N during local evening
and exits over Antarctica.
Alan
--
Alan Pickup | COSPAR site 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | SatEvo satellite page: http://www.wingar.demon.co.uk/satevo/