Re: USA-32 and its incredible flashing

From: Bob Christy (
Date: Fri Jul 09 2010 - 12:34:07 UTC

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      The visual comments tie up with the VHF radio transmissions that used 
    to come from USA-81. I never detected a similar transmission from USA-32.
    At times, the signal used to vary in strength at a rate that I estimated 
    at 4-5 radio 'flashes' per second - matching the comments on the visual 
    appearance. To the ear it sounded like a fast moving steam locomotive.
    As it was not there all of the time and I could't detect a pattern to 
    when it used to occur, I concluded that the phenomenon might be due to 
    radio reflections off a part of the satellite strucure that was rotating 
    Bob Christy
    Marco Lambroek wrote:
    Op 9-7-2010 11:46, Ralf Vandebergh schreef:
    >  I found this older message about the sat with comparable
    >  sightings in the archieve:
    For some recent photographic observations of the flashing behaviour of USA 32
    and it's sister ship USA 81, see:
    USA 32 shows a cycle of ~ 1.2 seconds with sometimes hints of a shorter (<1s)
    period superimposed.
    USA 81 shows a flash period of (multiples of) 0.2 seconds, I caught a
    spectacular naked eye stroboscopic show of it on June 2nd. Depending on the
    conditions (angle of view presumably, and/or orientation of rotation angle) it
    either shows a slow-peaked ~1.25s periodicity, or sharp glints with a period of
    0.2s or a multiple of that. So in that sense, USA 32 and USA 81 show comparable
    - Marco
    Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.  <>
    Cospar 4353 (Leiden):   52.15412 N, 4.49081 E (WGS84), +0 m ASL
    Cospar 4354 (De Wilck): 52.11685 N, 4.56016 E (WGS84), -2 m ASL
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