Vortex 6 - change of manoeuvre pattern

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Wed Jan 16 2013 - 21:49:51 UTC

  • Next message: Robert Holdsworth: "Re: Identification"

    Greg Roberts and Peter Wakelin have reported Vortex 6 (89035A / 19976) a recent no-show at longitudes expected based on
    its pattern of manoeuvres of recent years. The reason is that it no longer adheres to that pattern, as shown on the
    following chart:
    
    http://satobs.org/seesat_ref/misc/89035A_longitude_vs_epoch.pdf
    
    It used to manoeuvre about every 200 days to remain between approximately 35 E and 43 E, but last year it broke out of
    that pattern and began to move steadily eastward. It was last observed on 2012 Dec 15, by Greg, in the following orbit.
    It was near 58.5 E, drifting 0.224 deg/d east.
    
    1 19976U 89035A   12350.61234644  .00000000  00000-0  00000-0 0    01
    2 19976   7.2160  13.9354 0974210 242.6645 107.1056  1.00336520    07
    
    Mike McCants' int3 propagator places it near 66.4 E tomorrow night (Jan 17 UTC), drifting 0.221 deg/d east. 
    
    Barring further manoeuvres, it appears that it would oscillate between about 41 E and 108 E, over roughly an 860 day
    period. I would not be surprised if it does manoeuvre to take up a new position or range of longitudes. 
    
    Assuming that Greg first looked for it in the int3 propagated orbits before searching elsewhere, it may have manoeuvred
    sometime between Dec 15 and Jan 8, in which case it might be somewhere between 59 E and 64 E, if now roughly
    synchronous.
    
    Ted Molczan
    
    
    _______________________________________________
    Seesat-l mailing list
    http://mailman.satobs.org/mailman/listinfo/seesat-l
    



    This archive was generated by hypermail 2b29 : Wed Jan 16 2013 - 21:50:32 UTC