Fobos-Grunt: decay estimate

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Sat Dec 17 2011 - 16:18:45 UTC

  • Next message: ronlee@pcisys.net: "Re: Phobos-Grunt Online Flare Prediction"

    The mean rate of decay of the semi-major axis of the twenty-three (23) USSTRATCOM TLEs from epoch 11346.58616089 to
    11351.54320883 (2011 Dec 12 14:04 - Dec 17 13:02 UTC) was 1.3197 km/d. 
    
    Using the STOAG propagator and actual space weather during that period, I found that the mean rate of decay could be
    accounted for using A/m = 0.0013191 mē/kg and Cd = 2.2.
    
    Using those values with predicted space weather, STOAG propagates the orbit to decay on 2012 Jan 12. Estimated
    uncertainty is +/- 5 days, based on the rule of thumb of 20 percent of the time remaining to decay.
    
    I extracted the actual and estimated space weather data required by STOAG from data provided by Celestrak.com, which
    compiles data issued by official sources (mainly NOAA) and presents it in a convenient format:
    
    http://celestrak.com/SpaceData
    
    http://celestrak.com/SpaceData/SpaceWx-format.asp
    
    Ted Molczan
    
    
    _______________________________________________
    Seesat-l mailing list
    http://mailman.satobs.org/mailman/listinfo/seesat-l
    



    This archive was generated by hypermail 2b29 : Sat Dec 17 2011 - 16:19:31 UTC