Revised STS 110 elements for scheduled launch on 2002 Apr 08 UTC

From: Ted Molczan (molczan@rogers.com)
Date: Sun Apr 07 2002 - 18:40:10 EDT

  • Next message: Sue Wheatley: "ISS and docking"

    Well, my prediction was way off this time - by 3.25 minutes!
    
    Here are approximate OMS-2 elements for the announced launch time on
    2002 Apr 8 at 20:39:31 UTC, based on the initial orbit of STS 108:
    
    1 99999U          02098.88827450  .00025948  12201-4  18433-4 0    11
    2 99999  51.6368  41.9642 0011454 285.1487 252.4856 16.17009401    03
    
    The error in my prediction of Monday's lift-off time results from my
    algorithm's incompleteness. Specifically, at the coplanar time, if ISS
    is within a certain arc within its orbit, the shuttle has to cover more
    than 360 deg to catch up to it. The solution is simple enough: I just
    have to add 360 deg to ISS's argument of latitude at a certain point in
    the calculation. The challenge is to know with certainty the range of
    argument of latitude for which this is required.
    
    From my research, I had a rough idea of the range, and I thought that
    ISS would be well clear of it on Monday. Anyway, I now have a better
    knowledge of this range, and by adding 360 deg to ISS's argument of
    latitude at the coplanar time, the algorithm computes Monday's lift-off
    time to within three seconds of the announced time:
    
    Shuttle to ISS: Pad 39B Launch Time
    
        Launch     Coplanar    Lift-off
         Date        UTC         UTC
    -----------------------------------
     2002 Apr 08   20:41:26    20:39:34
     2002 Apr 09   20:17:46    20:13:47
     2002 Apr 10   19:54:05    19:51:16
     2002 Apr 11   19:30:23    19:25:29
     2002 Apr 12   19:06:42    19:02:58
     2002 Apr 13   18:43:00    18:40:27
     2002 Apr 14   18:19:19    18:14:40
    
    The above times should be accurate to +/- 5 s, except when they are off
    by 3 min.
    
    Ted Molczan
    
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Sun Apr 07 2002 - 18:40:18 EDT