Decay watch: 2000 Apr 27 #2

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Thu Apr 27 2000 - 13:49:47 PDT

  • Next message: Mark A. Hanning-Lee: "4/26 obs"

    #23834 = 96- 19 B = GPS 2-25 Delta 2 rocket
    
    Only two elsets appeared over the final 18 hours of this object's life,
    and the first of these, for epoch 00117.96 looks suspect and was ignored
    in my analysis. Despite this, the final elset... 
    GPS 2-25 r1      5.9  2.4  0.0  5.0 v   12       144 x 127 km
    1 23834U 96019B   00118.51427727  .42079649  13253-5  33611-3 0  8671
    2 23834  35.0267 183.8600 0012991 171.4994 189.0574 16.51367527228838
    ... is probably for the final northbound equator crossing and shows it
    running only 1.4 sec early against my previous prediction. I show this
    decay over the SW Indian Ocean at Apr 27 13:29 UTC +-4h near 34.0 S,
    52.3 E. This places it to the SE of Madagascar as it tracked north-
    eastwards towards an equator crossing over Indonesia. SpaceCom has it
    decaying a little earlier while southbound over the S Atlantic at Apr 27
    13:18 +-20m and 21.8 S, 16.0 W. There would have been a pass across the
    USA from the N of Los Angeles at 12:45 UTC to the S of Houston at 12:50.
    
    
    #26302 = 00- 21 B = Progress M1-2 Soyuz rocket
    
    The final elset...
    PrgM1-2 Soyuz r  6.0  3.0  0.0  5.0 d   15       142 x 133 km
    1 26302U 00021B   00118.36140886 -.22136931  12917-4 -21600-3 0   189
    2 26302  51.6341 157.5397 0006686 138.6205 221.3316 16.50689078   258
    ... has this running 2.4 seconds early against the prediction I posted
    earlier today. However, the negative drag leads me to treat it as
    suspect so that I hold to my earlier analysis that this may have decayed
    near a southbound equator crossing off the NE coast of Brazil at Apr 27
    10:51 UTC +-90m at 41.5 W. A little earlier it crossed eastwards over N
    America, passing N of Vancouver at 10:30 UTC, N of Minneapolis at 10:35,
    over Detroit at 10:37 and Washington DC at 10:39. SpaceCom's analysis
    places the decay close to Detroit (Apr 27 10:42 +-55m at 41.9 N at 82.9
    W) but the 55 min uncertainty suggests that it was not tracked on that
    orbit. My SatEvo prediction for the final two revs was:
    PrgM1-2 Soyuz r  6.0  3.0  0.0  5.0 d   15       149 x 138 km
    1 26302U 00021B   00118.36145331  .33648245  11013+1  46997-3 0 90171
    2 26302  51.6286 157.5487 0008616  89.8790 270.2197 16.48409667   258
    PrgM1-2 Soyuz r  6.0  3.0  0.0  5.0 d   15       131 x 124 km
    1 26302U 00021B   00118.42197323  .75665394  54183+1  42145-3 0 90172
    2 26302  51.6270 157.2012 0005552  90.1384 269.9252 16.54392913   262
    
    
    See http://www.wingar.demon.co.uk/satevo/dkwatch/ for more.
    
    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/
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www2.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Thu Apr 27 2000 - 13:54:02 PDT