USA 202 elements from observations by Greg Roberts

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Tue Feb 17 2009 - 19:21:46 UTC

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    Object 91142 / 09543A, tracked by Greg Roberts on 2009 Feb 12 and 15 UTC, is in
    fact the recently launched USA 202 (09001A / 33490), aka NROL-26.:
    
    http://satobs.org/seesat/Feb-2009/0268.html
    
    http://satobs.org/seesat/Feb-2009/0356.html
    
    As Greg said in his first report, he had a pretty good idea of its identity, and
    given the extreme brightness he observed - mag 2 to 4.5 just 11 deg above the
    horizon - it could only be a SIGINT bird with a huge antenna.
    
    USA 202          0.0  0.0  0.0 -0.2 v                35716 X 35937 km
    1 33490U 09001A   09046.30341339  .00000000  00000-0  00000-0 0    07
    2 33490   2.9191 337.6602 0026171 185.6682 174.3032  1.00132477    08
    Arc 2009 Feb 12.83 - 15.89, WRMS residuals = 0.003 deg
    
    At the epoch, it was located at 82.89 E, and drifting west 0.507 deg/d.
    
    Greg also extended the observational arc of USA 202's Delta 4 2nd stage:
    
    USA 202 r        0.0  0.0  0.0  2.0 v                35939 X 38085 km
    1 33491U 09001B   09046.43849096  .00000000  00000-0  00000-0 0    05
    2 33491   2.9765 333.7228 0247283  14.0035 346.6711  0.96058198    02
    Arc 2009 Jan 20.79 - Feb 15.79, WRMS residuals = 0.008 deg
    
    A cursory look at their elements reveals that upon deploying the payload into a
    35716 X 35937 km orbit and separating from it, the 2nd stage manoeuvred to raise
    its perigee from 35716 km to 38085 km, which became its new apogee. As a result,
    its original apogee became its perigee, and its argument of perigee shifted
    about 188 deg.
    
    When the payload reaches its planned longitude, it will manoeuvre to decrease
    its mean altitude by about 40 km, resulting in a geo-synchronous orbit.
    
    Ted Molczan
    
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