Re: Orbital surveillance satellites now exceed 1 inch resolution?

From: Robert Clark (bobbygc2001@yahoo.com)
Date: Tue May 01 2007 - 12:12:13 EDT

  • Next message: GlocalNet: "Re: Orbital surveillance satellites now exceed 1 inch resolution?"

     My reading of the discussion on the "Misty" type
    satellites suggests they are difficult to track
    visually.
     So how are these orbital elements so accurately
    determined to the degree that the amount of orbital
    decay they are experiencing can be determined?
    
    
       Bob Clark
    
     
    --- Björn Gimle (GlocalNet) <bg_26934@glocalnet.net>
    wrote:
    
    > It is "generally" agreed that what amateurs have
    > observed is a decoy.
    > See http://www.satobs.org/seesat/Dec-2005/0052.html
    > and the Reply liked from there!
    > 
    > ----- Original Message ----- 
    > From: "Robert Clark" <bobbygc2001@yahoo.com>
    > To: <SeeSat-L@satobs.org>
    > Sent: Tuesday, May 01, 2007 3:54 AM
    > Subject: RE: Orbital surveillance satellites now
    > exceed 1 inch resolution?
    > 
    > 
    > > Thanks for the informative response.
    > >
    > > Your description on this page of the "Misty"
    > > satellite gives it as one of the lightest
    > satellites
    > > for its physical dimensions:
    > >
    > > USA 144: The Mystery Deepens - Flash Timings
    > Needed.
    > > "SRP Analysis Reveals Area to Mass Ratio.
    > > SRP analysis has yielded an accurate estimate of
    > the
    > > object's area to mass ratio - more precisely, its
    > kA/m
    > > value - area to mass ratio multiplied by a
    > constant
    > > which accounts for its shape and reflectivity.
    > > The value of k can be between 1 and 2. A value of
    > kA/m
    > > of about 0.135 m^2/kg appears to account for the
    > > object's historical rates of orbital decay.
    > > Assuming k = 1.5, then A/m = 0.09 m^2/kg - at
    > least an
    > > order of magnitude greater than that of most
    > payloads
    > > and rocket bodies. For comparison, consider:
    > >
    > > Compton GRO 0.004 m^2/kg
    > > Hubble ST 0.006 m^2/kg
    > > UARS 0.007 m^s/kg"
    > > http://www.satobs.org/seesat/Aug-2002/0045.html
    > >
    > > This passage describes it as having a large
    > surface
    > > area for the given weight. But note this means it
    > also
    > > has a very low weight for its given surface area.
    > > A key feature of the James Webb Space Telescope is
    > > also its low weight for the size of its mirror.
    > This
    > > is because of its beryllium mirror which allows
    > very
    > > thin mirror blanks.
    > > So this low weight of the Misty satellites is
    > > consistent with lightweight, segmented beryllium
    > > mirrors.
    > >
    > >
    > >    Bob Clark
    > >
    > >
    > >
    
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