Updated elements

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Fri Sep 24 2010 - 13:57:09 UTC

  • Next message: Ted Molczan: "RE: New Satellite"

    Scott Campbell, Bob Christy, Bram Dorreman, Kevin Fetter, Tim Luton, Rob Matson, Mike McCants, Greg
    Roberts, Patrick Schmeer, Peter Wakelin, Brad Young, and I, contributed observations used to
    determine one or more of the following element sets.
    
    Scott's observations of AEHF 1, in the early hours of Sep 24 UTC, confirm the recent, small
    manoeuvre, centred on the apogee of Sep 22 at 21:41:57 UTC. Adding his observations to those of Tim
    Luton, from the night before, enables the elements to be refined:
    
    AEHF 1                                                4707 X 49983 km
    1 36868U 10039A   10267.19905349  .00000000  00000-0  00000-0 0    03
    2 36868  15.1729 298.8480 6713000 198.7207 113.6791  1.40208517    04
    Arc 20100923.07-0924.22 WRMS resid 0.003 totl 0.001 xtrk
    
    The period remains uncertain by perhaps several 10s of seconds, so expect at least that much time
    uncertainty tonight.
    
    I have updated the manoeuvre history to include the latest burn:
    
    http://satobs.org/seesat_ref/misc/AEHF_1_manoeuvres_v2.5.pdf
    
    I note that this burn is the smallest of the Segment 1 and 2 burns to-date, and total delta-V and
    estimated fuel consumption now slightly exceed (by ~6 percent) what I estimated was possible using
    fuel available after the aborted LAE (liquid apogee engine) manoeuvres. This may indicate that the
    REA (reaction engine assembly) manoeuvres have been, or are nearly completed. If so, then the
    spacecraft will cease its 0.1 rpm passive thermal control roll, and deploy its solar arrays, to
    enable operation of the 4.5 kW Hall Current Thrusters, which will complete the manoeuvres to reach
    the planned 4.8 deg, geo-synchronous orbit, sometime next summer.
    
    FIA Radar 1                                            1067 X 1080 km
    1 37162U 10046A   10267.02968548  .00000000  00000-0  00000-0 0    01
    2 37162 122.9931 105.9891 0008524  81.6596 278.5335 13.49540846    02
    Arc 20100923.02-0924.06 WRMS resid 0.023 totl 0.010 xtrk
    
    It appears that 10046A's orbit may be frozen in eccentricity and argument of perigee, which is a
    common feature of remote sensing satellites, especially radars. The orbits of the first four
    Lacrosses, and the mysterious USA 193, were similarly frozen. This finding is subject to
    confirmation through further observation, which should reveal that the argument of perigee
    oscillates about a value close to 90 deg, and the eccentricity oscillates about a value similar to
    that of the above elements.
    
    Ted Molczan
    
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