Decay watch: Iridium 69 rocket

Alan Pickup (alan@wingar.demon.co.uk)
Fri, 5 Jun 1998 03:49:23 +0100

The Long March 2C rocket responsible for Iridiums 69 & 71 will decay at
about June 7.2 (+-0.4 d) according to my current calaculations, though
the current 60d decay forecast "effective" on June 3 has/had it decaying
on June 4!

The rocket leaves eclipse near 51 deg N latitude 1-2 hours after local
midnight so is best placed for Europe and Canada. Eclipse entry occurs
over Antarctica. Note that perigee occurs in darkness while northbound
over the N hemisphere.

The most recent elset:
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            286 x 153 km
1 25321U 98026C   98155.99422698  .02758028 -13228-5  36552-3 0  1153
2 25321  86.3297 277.0210 0100441  34.7080 326.1774 16.20007709  5299

My SatEvo prediction, based on a fit through this and other recent
elsets:
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            281 x 152 km
1 25321U 98026C   98156.11768302  .03381908  32148-2  40996-3 0 91157
2 25321  86.3294 276.9510 0097579  34.1726 326.4517 16.21039297  5314
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            275 x 152 km
1 25321U 98026C   98156.30280749  .03568969  35251-2  40385-3 0 91156
2 25321  86.3290 276.8459 0093124  33.3686 327.2150 16.22325527  5349
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            266 x 151 km
1 25321U 98026C   98156.54940437  .03848313  40362-2  39359-3 0 91151
2 25321  86.3283 276.7055 0086834  32.2952 328.2336 16.24153071  5382
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            256 x 150 km
1 25321U 98026C   98156.79571332  .04169116  59042-2  38127-3 0 91157
2 25321  86.3276 276.5650 0080060  31.2202 329.2529 16.26125834  5423
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            245 x 149 km
1 25321U 98026C   98157.04170936  .04740245  91517-2  38011-3 0 91154
2 25321  86.3268 276.4241 0072667  30.1434 330.2729 16.28309217  5467
Iridm 69 CZ r   10.0  3.0  0.0  4.5 d            233 x 148 km
1 25321U 98026C   98157.28735202  .05573080  13986-1  37741-3 0 91157
2 25321  86.3259 276.2830 0064443  29.0645 331.2927 16.30828414  5507

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/