RE: TJM obs of 2003 Jun 06 UTC - USA 129 manoeuvred

From: Ted Molczan (molczan@rogers.com)
Date: Fri Jun 06 2003 - 07:55:16 EDT

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    Björn  wrote:
    
    > In addition to Ted's, I find only Alberto's obs 20:06 on or 
    > after the day of the 03155.82943925 elset. He reported it 
    > being late, but apparantly not enough to make analysts 
    > believe there was a maneouvre. It looks like 1.5 s from 
    > 03154.07799401 elset. Could there have been an inclination 
    > change at ascending node, though perigee is at 046 ?
    
    I doubt it. After adjusting for Earth's rotation, the object was within 0.04
    deg of the latest elements. One caveat is that I used reference stars nearly 1
    deg apart, so my accuracy probably was no better than 0.05 deg. 
    
    It is unfortunate that my passes happen to be almost exactly at perigee,
    because most reboosts have nearly zero affect on perigee distance.
    Observations made closer to apogee reveal the change in change in altitude
    above Earth, which I have found most helpful in narrowing down the range of
    perigee-crossings at which a manoeuvre could have been made.
    
    I very nearly missed the object last night. I was waiting for it near the
    predicted culmination of 38 deg in the west. When it was obvious that it was
    going to be late, I adjusted my aim a bit lower, to allow for Earth's
    rotation, but not enough. Suddenly, I saw a brief, bright flash that barely
    made it into the bottom of my field of view. I reacted quickly enough to catch
    up to it (it was moving at 1 deg/s), and so managed to obtain my one point. I
    had badly misjudged the rate of elevation adjustment needed to compensate for
    the late arrival and Earth's rotation - the object's low altitude above the
    Earth necessitated a greater rate of compensation.
    
    Weather forecast here is doubtful for tonight. The Clear Sky Clock indicates
    considerable cloud by 23 h local time, when the object is due, but much can
    change between now and then:
    
    http://cleardarksky.com/c/Torontokey.html
    
    Ted Molczan
    
    
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