Decay watch: 2000 Sep 8

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Fri Sep 08 2000 - 13:17:17 PDT

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    In a warning dated 2088 February 20, SpaceCom is predicting the decay of
    #22 = 59- 9 A = Explorer 7 on 2088 February 27 at 01:22 +-2 min. Some
    mistake, I suspect.
    
    Otherwise, from my updated Decay Watch page...
    _____________________________________________________________________
    
    #10362 = 77- 91 A = Cosmos 955
    
    Final decay analyses:
       SpaceCom: Sep  7 19:07 +-51m       38.7 N    37.5 W
       SatEvo:   Sep  7 18:58 -20+30m     19.8 N    40.3 W
    
    Final elsets:
    Cosmos 955       5.0  1.5  0.0  5.4 v   24       141 x 124 km
    1 10362U 77091A   00251.72658542  .24099736  00000-0  18090-3 0  6160
    2 10362  81.1767 228.2965 0012902 233.0568 127.0179 16.52481185261781
    Cosmos 955       5.0  1.5  0.0  5.4 v   24       138 x 134 km
    1 10362U 77091A   00251.73738821  .16256400 -88171-6  16341-3 0  6174
    2 10362  81.1625 228.2676 0002405 108.0005 316.2839 16.51290804261787
    
    Neither of the two final elsets appears perfect - the first may have a
    too-high eccentricity and the second indicates an unlikely shift in the
    perigee around the orbit. The two orbits differ in equator crossing time
    by 1.5 sec, being respectively 0.02 sec (!) early and 1.5 sec late with
    respect to my final pre-decay prediction which satisfied the previous 7
    elsets with a mean residual of 0.09 sec and a maximum residual of 0.24
    sec. The final elset of this prediction is:
    Cosmos 955       5.0  1.5  0.0  5.4 v   24       131 x 127 km
    1 10362U 77091A   00251.72655319  .63055520  56252+1  42015-3 0 96157
    2 10362  81.1717 228.2932 0003463 223.9331 136.0394 16.53980418261781
    
    I show this decaying northbound over the Atlantic to the north of 
    Brazil.
    _____________________________________________________________________
    
    Object: #14693 = 84- 11 E = Palapa B2 r (PAM-D)
    
    SpaceCom has not renewed its estimate for this decay to occur on
    September 9, which must be an error. My current estimate is for
    September 24 +-6d.
    _____________________________________________________________________
    
    
    Alan
    -- 
    Alan Pickup / COSPAR 2707:  55d53m48.7s N   3d11m51.2s W      156m asl
    Edinburgh  / SatEvo & elsets:    http://www.wingar.demon.co.uk/satevo/
    Scotland  / Decay Watch: http://www.wingar.demon.co.uk/satevo/dkwatch/
    
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    This archive was generated by hypermail 2b29 : Fri Sep 08 2000 - 13:20:16 PDT