Decay watch: 2000 Jan 18

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Tue Jan 18 2000 - 00:17:33 PST

  • Next message: Tony Beresford: "Re: Decay watch: 2000 Jan 18"

    SpaceCom has issued a decay warning for Molniya 1-57 (#13964 = 83 25 A),
    predicting the decay for 2000 Jan 18 23:53 +-12h. The latest two elsets
    for this are:
    
    Molniya 1-57                                     17673 x 112 km
    1 13964U 83025A   00017.47231975  .24275053 -62284-5  75672-2 0  2120
    2 13964  62.6204  86.1367 5749795 269.1184  28.4376  4.60114414123420
    Molniya 1-57                                     16319 x 89 km
    1 13964U 83025A   00018.16225747  .00061526 -25963-5  62270-5 0  2136
    2 13964  62.5906  85.7510 5564675 268.8927 125.7718  4.93058053123452
    
    The drag term in the latest elset is much too low, while the 
    perigee height implied by the previous elset is too high.
    With the perigee being forced lower by luni-solar gravitational
    effects, which SatEvo does not model, expect the Molniya to run 
    early with respect to my orbit prediction:
    
    Molniya 1-57                                     15769 x 90 km
    1 13964U 83025A   00018.51145827  .25965451  15705-1  25547-2 0 92132
    2 13964  62.5906  85.5625 5479255 268.9048  31.1612  5.07337094123477
    Molniya 1-57                                     14643 x 90 km
    1 13964U 83025A   00019.08624672  .28907271  18523-1  25752-2 0 92133
    2 13964  62.5906  85.2304 5294054 268.9263  32.9636  5.38830418123500
    
    I doubt, though, whether it will decay today, as SpaceCom predict. I
    also fear that SpaceCom may be on the verge of losing this for a couple
    of days.
    
    More details at http://www.wingar.demon.co.uk/satevo/dkwatch/
    
    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/
    
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