Re: [APML] OT: Satellite orbital taxonomy

["Paul M. Rybski" <rybskip@idcnet.com>]

>At 10:07 PM 5/22/2002, Paul M. Rybski wrote:
>>     ...that was why this location was such a good one in which to 
>>park a spy satellite.  To find a geosynchronous satellite, you park 
>>a telescope at a specific altitude and azimuth, don't move it and 
>>make lots of integrations.  During those integrations, stars will 
>>track through your field and possibly ruin an exposure of a fixed 
>>target.  The more stars, the better.  Couple trailing stars with a 
>>faint object moving orthogonally to the stars and you create a spy 
>>satellite that is very difficult to find.  Then add orbit changes 
>>to this motion and you end up with a devilishly difficult object to 
>>find.  I know because I had to do it and succeeded.  But not 
>>without a very large (2.7 meter aperture) telescope and not without 
>>knowing the orbit of the satellite.  With that same large telescope 
>>but without knowledge of the orbit, I would not have had a prayer 
>>of finding this very faint object, even away from the Milky Way 
>>plane.  Note that a US quarter ($0.25 piece) placed a 
>>geosynchronous distance will exhibit a maximum magnitude of 18.  My 
>>object was fainter than that most of the time.  However, during 
>>maneuvering or at one specific Sun-satellite-observer geometry, the 
>>object could glint after sunset or before sunrise just like the 
>>object in the photo under discussion...
>
>Paul,
>
>That's really interesting. That info isn't classified? Obviously not I guess.


      Let's just say it was supposed to be declassified in 1992.


>When you say that the target was darker than a quarter, it must have 
>been completely painted flat black (or even flocked), right?


      No.


>Was it solar powered?


      No.


>How can solar collector panels be made stealthy? Is that why you saw a glint?


      If you wanted to look down on an enemy's installations 24/7 but 
didn't want him to successfully detect you by diffuse reflection off 
of satellite surfaces or by Kelvin retroreflection off of your solid 
state detectors when he painted you with a pulsed laser and looked 
for reflections synchronously at the time of the expected return 
pulse, what would you hide the satellite behind?  (Hint:  What would 
make you invisible most of the time but glint brightly at only one 
orientation with respect to you and to the Sun?)  (Another hint: 
This object was the brightest infrared source in the sky -- after the 
Sun, of course -- at 10 microns.  How could it be so bright in the IR 
but nearly invisible in the visible?)


>Such satellites must have limited expected service life.


      Yes.


>Don't they use up their propellant to change orbit?


      Yes.


>How long will it take for a typical one of these satellite's orbit to decay?


      A long time if they are at synchronous altitude . . . !


>Matt BenDaniel
>matt@starmatt.com
>http://starmatt.com


Paul


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