Re: All that glitters is USA 32...

From: Rick Baldridge (rickbaldridge@msn.com)
Date: Fri May 25 2001 - 20:49:46 PDT

  • Next message: Robert Smathers (SSSSC Sat Shack): "USA 129 - appears to be flashing now!"

    Ed Cannon wrote:
    > I first learned about their behavior from Mike McCants, and in
    > quite a few observations have concluded that the wild sparkling
    > that they do is probably predictable, like a "flare" -- but one
    > produced by a (rapidly) rotating multifaceted reflector.  <snip>
    > Mike pointed out to me long ago, and
    > it still seems fully accurate, that they glitter or sparkle most
    > brightly at least when south of us, after culmination.
    _______________________________________________
    
    More likely the "sparkle" or "glitter" is from thermal insulation foil
    covered with Kapton (yellow-gold in color). I have seen USA 32 and 81 many
    times and believe the glitter phenomenon is from this material as the
    satellite slowly rotates. The glittering frequency is too quick and far too
    numerous to be caused by even a few dozen flat surfaces -- it has to be into
    the hundreds of surfaces flashing over the course of 5 to 10 seconds.  My
    speculation is that only a crinkled surface like Kapton-covered foil can
    produce such an effect. (Can anyone confirm this hypothesis, however?)  Many
    satellites have this material used as insulation/thermal management.  See:
    http://www.spaceflightnow.com/titan/b28/
    for an image of this material on a Lacrosse satellite, which I have seen
    produce (albeit rarely) the same effect on these vehicles.  I can confirm,
    per Ed's and Mike's note, the glittering is MUCH more pronounced when the
    vehicle is more fully illuminated (smaller phase-angle).
    
    RICK BALDRIDGE
    Campbell, CA  USA
    
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