Decay watch: Mar 23

Alan Pickup (alan@wingar.demon.co.uk)
Tue, 23 Mar 1999 21:27:02 +0000

A late elset for the late Proton, the MPL Delta came down on schedule
and the first decay warning for the Iridium 11A S/D...

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Object: #25658 = 99- 13 B = AsiaSat 3S Proton r

Final final elset:
AsiaSat 3S Proton r                              144 x 120 km
1 25658U 99013B   99081.52484637  .32472972  12725-4  20240-3 0   117
2 25658  51.5919 181.2330 0018338 264.3768  95.5186 16.52671664   250

Note: This does not alter my conclusion concerning yesterday's decay,
other than to reduce the uncertainty by a few minutes.
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Object: #25607 = 99-  1 C = Mars Polar Lander Delta 2 r1

Decay predictions:
Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Mar 14 14:32     Mar 23 03:32 +-5d        12.3 N    67.2 W
SpaceCom   Mar 16 01:23     Mar 23 01:19 +-4d        11.5 S   149.0 E
SpaceCom   Mar 19 06:49     Mar 23 06:32 +-2d         9.1 N   105.9 W
SpaceCom   Mar 20 03:19     Mar 23 00:39 +-2d         7.6 N    11.9 W
SpaceCom   Mar 21 00:43     Mar 23 00:22 +-1d        25.7 N    75.0 W
SpaceCom   Mar 22 00:48     Mar 23 01:10 +-15h       23.9 S   110.1 E
SpaceCom   Mar 22 12:06     Mar 23 00:36 +-9h        13.1 N    23.7 W
SpaceCom   Mar 23 01:03     Mar 23 01:49 +-51m       25.9 N   103.3 W
SpaceCom   Mar 23 02:12     Mar 23 01:49 +-1m        25.9 N   103.6 W

SatEvo     Mar 15 21:20     Mar 23 01:00 +-2d
SatEvo     Mar 16 20:45     Mar 22 21:17 +-1.5d
SatEvo     Mar 19 19:30     Mar 23 03:23 +-18h       17.7 N    79.9 W
SatEvo     Mar 20 23:25     Mar 23 00:22 +-10h       23.4 N    55.3 W
SatEvo     Mar 21 20:20     Mar 23 01:22 +-6h         0       172.0 E
SatEvo     Mar 22 21:40     Mar 23 01:22 +-4h         0       171.7 E
SatEvo     Mar 23 20:40     Mar 23 01:52 +-25m       22.2 N    72.5 W

Final elset:
MPL Delta 2 r1   5.9  2.4  0.0  5.0 d            157 x 133 km
1 25607U 99001C   99081.99717650  .42740142 -12150-4  56095-3 0  1684
2 25607  25.8306  13.1233 0018272 116.1167 243.9054 16.47876139 12194

Note: The final elset shows it running 21 seconds late with respect to
yesterday's SatEvo prediction. I wonder if SpaceCom's ultra-precise 
decay report indicates that the decay was witnessed (over NE Mexico, 
W of Brownsville, TX). The SpaceCom time appears to be for "ground 
impact" while my estimate is for the re-entry event which I place 
further along the track near perigee, SE of the Bahamas.
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Object: #25580 = 98- 74 D = Iridium 11A Smart Dispensor

Decay predictions:
Source   Prediction made    Predicted decay at      Latitude Longitude
               UTC                UTC                  deg      deg

SpaceCom   Mar 23 10:26     Apr  2 10:53 +-6d        50.3 S    25.0 W

SatEvo     Mar 23 20:40     Apr  2 00:00 +-2.5d

Latest elset:
Irid 11A S/D     4.0  2.0  0.0  5.5 d            346 x 182 km
1 25580U 98074D   99082.64095980  .00899599  00000-0  52304-3 0  1771
2 25580  86.3001 148.8013 0123655 142.5277 218.5413 16.03768227 14769

Note: This is poorly placed for observation. It enters eclipse while 
northbound near 67 deg S latitude at ~21h local time; it leaves 
eclipse near 71 deg N at ~23h local time while still moving northwards.
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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/