RE: AEHF 1 - Segment 2 Burn 2 estimated elements

From: Derek C Breit (breit_ideas@poyntsource.com)
Date: Thu Sep 09 2010 - 22:05:44 UTC

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    I will try this at 2:48 ish UT (7:48 PDT) (with the second possible point at
    about 8 minutes later) in The Teapot..
    
    If anyone observes it sooner, please let me know which point it is closer
    to!..
    
    I am just returning to normal after a weeks illness, but I'll see if I can't
    get a couple quick points..
    
    Derek
    
    -----Original Message-----
    From: seesat-l-bounces+breit_ideas=poyntsource.com@satobs.org
    [mailto:seesat-l-bounces+breit_ideas=poyntsource.com@satobs.org] On Behalf
    Of Ted Molczan
    Sent: Thursday, September 09, 2010 9:47 AM
    To: SeeSat-L@satobs.org
    Subject: AEHF 1 - Segment 2 Burn 2 estimated elements
    
    
    Hobbyists have documented the results of each of the six burns performed by
    AEHF 1, as summarized below.
    
                            Per  Apo   Inc
    Seg Burn  Date   UTC     km   km   deg   
      COLA   Aug 20         278 49989 22.10
     1    1  Aug 29 14:52   446 49975 21.62
     1    2  Aug 31 13:25   589 49992 21.21
     1    3  Sep 02 12:09   791 49983 20.81
     1    4  Sep 04 11:05   982 49981 20.36
     2    1  Sep 07 01:58  1146 49994 19.96
    
    Brad Young reported the most recent observations, made just over an hour
    after Burn 1 of Segment 2. The observational arc was too short to determine
    the new orbital elements using orbit analysis methods, so I estimated them
    based on the estimated time of the burn, and assuming effects similar to
    those of the Segment 1 burns, which happen to closely agree with Brad's obs:
    
    Segment 2 Burn 1 estimate                             1164 X 49994 km
    1 70002U          10250.08178243  .00000000  00000-0  00000-0 0    03
    2 70002  19.9600 304.5991 7640000 190.5461 180.0000  1.52000000    07
    
    The Segment 1 burns occurred at nearly 2 day intervals. The first Segment 2
    burn occurred 2.5 days after the final Segment 1 burn. My guess is that
    subsequent burns will now occur at nearly 2 day intervals, in which case, it
    should have manoeuvred today (Sep 09) near the apogee of 01:20:38 UTC, with
    approximately this result:
    
    Segment 2 Burn 2 estimate                             1344 X 49995 km
    1 70003U          10252.05599538  .00000000  00000-0  00000-0 0    07
    2 70003  19.5600 304.2021 7590400 191.3667 180.0000  1.51355000    02
    
    My recommendation for anyone considering further observations, is to be
    prepared for the object to appear near either of the above orbits, and
    failing that, somewhat later and off-course relative 70003.
    
    In the press-briefing of Aug 30, the USAF stated that the Segment 2 burns
    would more than double the perigee achieved by Segment 1, which suggests
    ~2000 km. Assuming the failed LAE (liquid apogee
    engine) has conventional performance characteristics, I estimate that the
    REA (reaction engine
    assembly) now being used, may also be able to achieve nearly the 6 deg
    inclination intended to have been achieved by the LAE. Whether or not that
    is planned, and in what sequence, I do not know. 
    
    Segments 3 and 4 will consist of much smaller manoeuvres, using the Hall
    Current Thrusters, which should present less of a challenge to observers to
    keep up with, than the first two segments.
    
    Ted Molczan
    
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