Re: Light Curve from Satellite Trail

From: John Locker (john@satcom.freeserve.co.uk)
Date: Fri Jan 11 2008 - 11:12:36 UTC

  • Next message: John Locker: "Re: Light Curve from Satellite Trail"

    I suppose really I am basing my specualtion on the latest "known" design
    
    http://www.globalsecurity.org/space/systems/images/lacrosse6.jpg
    
    plus a number of other factors...but as I'm something of a novice as far as 
    sat design is concerned...I admit we are into the realms of speculation.
    
    What we do know is that L4 and 5 , and possibly L3 can disappear.
    However , as illustrated by my imaging last year.....they disappear to the 
    naked eye , but not completely.....I think Phil estimated down to mag 6-7 
    from mag 2.
    
    There is nothing on the above illustration that could cause such instant 
    shadowing.The wings may be long , but I doubt they have the area to cause 
    such a dimming.
    Of course the plan could be way out..................or incomplete !
    
    The sinister patch that Ted uncovered , which is undoubtedly that of  L4 , 
    isnt just announcing another bird in orbit.I think whoever designed the 
    patch had some knowledge of the bird and couldnt resist leaving a clue or 
    two.
    
    
    http://www.collectspace.com/images/news-083100a.jpg
    
    to this end , it is possible that the mesh design either side of the "eye" 
    is in fact indicative of  the stealth cover.......almost like a  nictitating 
    membrane.Perhaps that is why an owl was chosen to represent this generation 
    of Lacrosse craft.
    The Titan IV B-28 patch leaves us in no doubt that the eyes are that of an 
    owl!
    
    
    > If the casing is non-reflective, it absorbs light AND heat, and if close
    > to the satellite, how would the satellite be cooled?
    > A detached panel, shading the Sun, would serve both purposes
    > (and it could even be the solar panel - or radar antenna)
    
    I would agree , and thats why I think the "shades " are stand-off  on some 
    type of gimbal affair.
    I just dont think its co-incidence that the bird can disappear almost at 
    will.
    
    Of course the other question is , on a high elevation pass over Europe , who 
    is it "hiding " from ?
     We are into the realms of science fiction here. This isn't a Star Wars 
    /Star Trek cloaking device , but simply a mechanical shield.
    
    Thats my take ................. someone somewhere knows the truth about 
    Lacrosse and until we can get some better images we can only speculate.
    
    Its a shame USA 193 isnt the same design because at the rate it is decaying 
    I think by the middle of the  year it will be down to about 240km and 
    present a rather nice imaging opportunity :O))
    
    John
    
    
    
    
    
    
    
    ----- Original Message ----- 
    From: "Björn Gimle at ComHem" <b.gimle@comhem.se>
    To: <SeeSat-L@satobs.org>
    Sent: Friday, January 11, 2008 7:43 AM
    Subject: Re: Light Curve from Satellite Trail
    
    
    > >I agree to some extent Björn , especially in the case of structures like 
    > >ISS where we see obvious shadowing from the large solar arrays....but 
    > >that shadowing is only noticed when we look at images taken at high 
    > >magnification.From the ground the naked eye observer wouldnt really be 
    > >aware
    >
    > I don't follow your argument here - if (a substantial) part of the 
    > satellite
    > is (more than usual) shadowed, the total magnitude would be reduced.
    >> .
    >>
    >> L5 and possibly 3 and 4 seem to have  a more "on / off" ability to change 
    >> brightness.
    >>
    >> In some reports it is muted that MISTY used some sort of inflatable 
    >> device to cloak itself....I think that highly unlikely....but rather it 
    >> used a simply mechanical system and so too  Lacrosse . Perhaps light 
    >> absorbing , non reflective panels which encase the outer structure when 
    >> required. Of course if that was the case , why not leave the panels in 
    >> situ all the time to stop the satellite reflecting at all.
    >>
    > If the casing is non-reflective, it absorbs light AND heat, and if close
    > to the satellite, how would the satellite be cooled?
    > A detached panel, shading the Sun, would serve both purposes
    > (and it could even be the solar panel - or radar antenna)
    >
    >
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