NOSS 3-3 elements

From: Ted Molczan (molczan@rogers.com)
Date: Sun Mar 13 2005 - 12:12:44 EST

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    NOSS 3-3 (A)     0.0  0.0  0.0  4.0 v
    1 28537U 05004A   05071.85691448  .00000011  00000-0  20000-4 0    03
    2 28537  63.4359  66.8198 0128055 179.5464 180.5699 13.39754399    03
    Arc 2005 Mar 03.83 - 12.87, WRMS residuals = 0.027 deg
    
    NOSS 3-3 (C)     0.0  0.0  0.0  4.0 v
    1 28541U 05004C   05071.85700506  .00000011  00000-0  20000-4 0    04
    2 28541  63.4372  67.0105 0128275 179.3702 180.7507 13.39754976    02
    Arc 2005 Mar 08.99 - 12.88, WRMS residuals = 0.022 deg
    
    NOSS 3-3 r       0.0  0.0  0.0  4.7 v
    1 28538U 05004B   05071.84923411  .00000030  00000-0  50000-4 0    05
    2 28538  63.8239  68.1460 0136307 175.2018 185.0354 13.42846713    03	
    Arc 2005 Mar 07.14 - 12.87, WRMS residuals = 0.020 deg
    
    Description of 2-line elements: http://www.satobs.org/element.html
    
    I no longer believe that 05004C raised its orbit between the observations of
    2005 Mar 09 at 10:55 UTC, and Mar 10 at 12:00 UTC; therefore, I have reinstated
    the earlier arc starting date/time that I used previously.
    
    It will be interesting to see how long the payloads cruise at their present mean
    motion before manoeuvring to match that of the other operational groups, near
    13.40465 rev/d.
    
    Perhaps the upper limit could be deduced by the date at which the nearly
    coplanar 91076C,D,E group would overtake 05004A,C. As of the above epoch, their
    node crossings trailed those of 05004A,C by 2197 s, closing at the rate of about
    45.8 s/d, which puts the overtaking date about 48 d later, or about Apr 29.
    
    Presumably, optimal spacing would not have the these groups above the horizon at
    the same time, so the manoeuvre to station-keep should come well before or after
    that date.
    
    Another possibility is for 05004A,C to manoeuvre to an intermediate cruising
    mean motion, and remain there for some time, before their final manoeuvre to
    station-keep. As I noted in an earlier post, the NOSS 3-1 and 3-2 groups cruised
    for several months at a temporary mean motion within approx +/- 0.0015 rev/d of
    the operational mean motion.
    
    Regardless of when it is achieved, any station-keeping with 91076C,D,E will be
    in time only, because 91076C,D,E's plane will drift nearly 0.009 deg/d west
    relative 05004A,C's.
    
    Ted Molczan
    
    
    
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