RE: USA 144 debris

From: Ted Molczan (ssl2molcz@rogers.com)
Date: Mon Dec 31 2007 - 08:31:00 UTC

  • Next message: Greg Roberts: "Optical 31 Dec 2007"

    Gordon wrote: 
    
    >     I recently observed 1999-028C with the unaided eye. 
    > Calsky informs me that it is debris from USA 144 with a 
    > magnitude of 4.8 and an orbit 2680kmx3140km. To be visible at 
    > all this must be quite a piece of debris!
    
    It is an unusual object. Until 2002, it was generally believed to be the
    payload, mainly due to its brightness, and so we used to call it 99028A.
    
    There were a couple of problems with the theory that it was the payload. It
    rotated slowly, and it exhibited apparent orbital drag that was about 10 times
    greater than expected for a payload at its altitude. 
    
    In 2002, a re-analysis of our large collection of hobbyist observations revealed
    that the apparent drag was due to solar radiation pressure, which led to the
    conclusion that the object was debris-like, as posted here:
    
    http://satobs.org/seesat/Aug-2002/0045.html
    
    In a follow-up message I speculated that the object could be a decoy, intended
    to draw attention away from the deployment of the actual payload, which now is
    generally believed to be the second Misty stealth imaging reconnaissance
    satellite, probably in a quasi 65 deg, 700 - 800 km orbit:
    
    http://satobs.org/seesat/Aug-2002/0075.html
    
    In recognition that the object in question cannot be the payload, we eventually
    changed our designation for it to 99028C.
    
    
    > Can anyone tell me what it is and how large it is?
    
    Some of us believe the decoy theory; others prefer the debris theory; at this
    time there is no way to be certain which theory is correct.
    
    I estimate that it is about 5 m across, with a mass of perhaps a few hundred
    kilograms.
    
    > Is there an on-line catalogue of debris, with descriptions?
    
    Jonathan McDowell maintains an excellent catalogue of all objects ever launched
    into orbit, which identifies many pieces of debris cast off during the launch
    and deployment of satellites, as well as those resulting from fragmentations:
    
    http://www.planet4589.org/space/log/launchlog.txt
    
    Ted Molczan
    
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