VAFB Atlas 2AS - How Many NOSS?

From: Ted Molczan (molczan@rogers.com)
Date: Sat Nov 29 2003 - 11:08:06 EST

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    Other than the launch itself, scheduled for early 2003 Dec 02 UTC, the only
    suspense relates to the number of NOSS satellites to be deployed.
    
    Though the 2001 launch deployed only two NOSS, I have always believed that three
    were on board, and that one of them failed to separate from the Centaur stage.
    
    The eleven previous NOSS successfully launched between 1971 and 1996, all
    consisted of three satellites orbiting in a close triangular formation. They are
    believed to detect radio transmissions from ships at sea, and analyze the
    signals to triangulate on the precise location of the transmitter. This enables
    the U.S. Government to locate and track foreign vessels of interest.
    
    Although I have no expert knowledge of the operation of the NOSS, it is my
    belief that three satellites are required to most accurately determine the
    position of transmitters, so the unprecedented deployment of only two NOSS after
    the 2001 launch was a great surprise.
    
    Hobbyists closely tracked both NOSS as they manoeuvred into their final orbits.
    During the first couple of months after launch, both made several small
    manoeuvres that varied the distance between them. For a short time, they were
    1500 km apart, then gradually moved to within the normal 60 km distance. I
    speculate that the changes in distance may have been experiments to determine
    the optimal spacing of the two spacecraft, to salvage as much ship-locating
    accuracy as possible, after the loss of the third spacecraft.
    
    US News & World Report published an article on 2003 Aug 11 (abstract below),
    reporting problems with the NOSS and the KeyHole satellite launched in 2001:
    
    http://www.usnews.com/usnews/issue/archive/030811/20030811041138_brief.php
    
    From my copy of the article, the quotes relevant to NOSS:
    
    "Not long after launch on Sept. 8, 2001, the satellite initially failed to
    operate once in orbit. "We had a problem shortly after launch," a company
    spokesman told U.S. News."
    
    "In fact, an electronic circuit on the satellite had failed to work. Says a
    Lockheed Martin spokesman: "We fixed the problem. There was no impact to mission
    ops." Still, he acknowledges, "It didn't work perfectly."" 
    
    "Three current and former government officials tell U.S. News that the satellite
    is still not up to par. Soon after it failed, Lockheed Martin engineers were
    able to save the satellite by tinkering with its software. The officials say
    Lockheed Martin was able to recover about 80 percent of the satellite's
    capability. But the satellite's crippled performance has resulted in many
    boardings of cargo ships that Navy officials mistakenly believed were controlled
    by suspected al Qaeda terrorists, says one of the sources."
    
    I interpret, "electronic circuit on the satellite had failed to work" as the
    failure of the deployment mechanism of the 3rd satellite.
    
    The recovery of "about 80 percent of the satellite's capability" "by tinkering
    with its software", also seems consistent with the loss of one of the three
    satellites.
    
    In any case, the upcoming launch should settle the question of the intended
    number of satellites. The probability of a second consecutive deployment failure
    must be incredibly small, so if once again we see only two NOSS, then that must
    be the intended number. I expect three, but we'll know soon enough.
    
    Ted Molczan
    
    
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