NOSS 3-2 post manoeuvre elements

From: Ted Molczan (molczan@rogers.com)
Date: Tue Dec 09 2003 - 20:13:17 EST

  • Next message: paul: "obs 10dec 03344 8305"

    In my earlier update, for epoch 03342.7, I did not include the Centaur, because
    Russell Eberst's single observation had it running 0.79 s late. 
    
    Russell checked his reduction, but found all in order. He had used an excellent
    star pair, and his position agreed closely with my epoch 3341.76 elset, so I
    decided to let future obs resolve the matter.
    
    Peter Wakelin's obs of consecutive passes ending at epoch 03343.79, revealed the
    object running later still, proving that Russell's point is indeed accurate, and
    indicating that the object had recently gained altitude.
    
    First, I looked for a single-impulse event, and found some indication of one on
    2003 Dec 07, between about 17 h - 18 h UTC. However, it would have been very
    tiny, reducing the mean motion by just 0.00012 rev/d, so I evaluated the
    alternative: a steady acceleration over the entire arc since launch.
    
    This produced an excellent fit to most of the points since late Dec 03 UTC, with
    a significant negative rate of decay, so I suspect the Centaur is still venting
    propellant, and getting a tiny boost as a result.
    
    Observation arc 2003 Dec 07.70 - 09.80 UTC:
    
    NOSS leader      0.0  0.0  0.0  4.9 v
    1 71001U 03054A   03343.77910648  .00000057  00000-0  10000-3 0    05
    2 71001  63.4259 285.0442 0127151 180.9376 179.1429 13.39783980    00
    
    WRMS residuals = 0.014 deg
    
    Observation arc 2003 Dec 07.70 - 09.80 UTC:
    
    NOSS trailer     0.0  0.0  0.0  4.9 v
    1 71002U 03054B   03343.77945003  .00000057  00000-0  10000-3 0    09
    2 71002  63.4329 285.0679 0124587 180.9254 179.1558 13.39757203    08
    
    WRMS residuals = 0.017 deg
    
    Observation arc 2003 Dec 03.97 - 09.79 UTC:
    
    NOSS 3-2 r      10.1  3.0  0.0  3.7 v
    1 71003U 03054C   03343.77469956 -.00002230  00000-0 -38302-2 0    09
    2 71003  63.6867 284.6485 0139957 183.5168 176.4888 13.40519591    02
    
    WRMS residuals = 0.020 deg
    
    Ted Molczan
    
    
    
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