Decay watch: 2001 Feb 9

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Fri Feb 09 2001 - 10:10:50 PST

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    From my updated Decay Watch page...
    _____________________________________________________________________
    Object: #26606 = 00- 71 B = GPS 47 Delta 2 rocket
    
    Final decay analyses:
    Source   Prediction made    Predicted decay at      Latitude Longitude
                   UTC                UTC                  deg      deg
    SpaceCom   Feb  8 20:56     Feb  8 19:12 +-7m        37.0 S   149.0 E
    SatEvo     Feb  9 17:50     Feb  8 18:55 +-1h        15.6 S    67.8 E
    
    Final elsets:
    GPS 47 Delta r   7.0  2.0  0.0  5.5 d   15       212 x 121 km
    1 26606U 00071B   01039.63225463  .14401474  00000-0  17852-3 0  1894
    2 26606  37.5173 290.4097 0069026 162.5795 197.7969 16.39795973 13547
    GPS 47 Delta r   7.0  2.0  0.0  5.5 d   15       198 x 136 km
    1 26606U 00071B   01039.63225688  .14784469  37195-5  36380-3 0  1911
    2 26606  37.5075 290.4258 0047410 174.7115 185.4191 16.39580550 13545
    GPS 47 Delta r   7.0  2.0  0.0  5.5 d   15       190 x 92 km
    1 26606U 00071B   01039.75357097  .29084828  00000-0  96601-4 0  1904
    2 26606  37.5033 289.5053 0074888 158.4208 202.0356 16.49416004 13566
    
    Note: It has been difficult, indeed impossible, to reconcile the 
    various final elset issued for this object. For example, the final two
    show the perigee dropping by 44 km while the apogee fell only 8 km -
    somewhat the wrong way around. In the end, I have all but ignored the 
    final elset in my analysis, deriving the following elset instead
    which has an equator crossing time 5 sec later than that published by
    SpaceCom:
    GPS 47 Delta r   7.0  2.0  0.0  5.5 d   15       157 x 121 km
    1 26606U 00071B   01039.75360976  .57461099  21987+1  43130-3 0 91818
    2 26606  37.5166 289.5474 0027073 181.7216 178.2690 16.50199063 13562
    I put the decay southbound over the Indian Ocean, but with a large 
    uncertainty given that poor quality of the published data. In fact, 
    Tony Beresford has forwarded an observation of what appears to be the
    re-entry of this rocket seen from south-eastern South Australia at
    19:15 UTC. This time may be 3-4 minutes too late, but the location
    is very much in accordance with SpaceCom's estimated decay point.
    _____________________________________________________________________
    
    
    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 Feb 09 2001 - 10:13:13 PST