More on the KH-11/CRYSTAL constellation changes

From: Marco Langbroek (marco.langbroek@online.nl)
Date: Mon Sep 16 2013 - 14:35:29 UTC

  • Next message: Russell Eberst: "2013SEP16-17.OBS"

    Hi all,
    
    On 14-9-2013 14:14, I wrote:
    
    > For those interested: I have just written a blog post outlining what I expect to
    > be the character and potential time-line of changes to the KH-11/Enhanced
    > CRYSTAL ("Keyhole") constellation, following the recent launch of USA 245
    > (NROL-65) last August 28:
    >
    > http://sattrackcam.blogspot.nl/2013/09/on-usa-245-and-usa-129-and-future-of.html
    
    Over the past weekend I extended my analysis, the results of which have been 
    written up here:
    
    http://sattrackcam.blogspot.nl/2013/09/past-and-future-of-kh-11-keyholeevolved.html
    
    The post includes a diagram that maps, for each KH-11, the RAAN value on July 
    1st in the period 2005-2013.
    
    It confirms that the constellation consists (as we already knew) of a primary 
    East and West plane separated by 48-50 degrees. It also confirms that there are 
    two secondary orbital planes at 10 deg west of the primary West plane, and at 20 
    degrees east of the primary East plane. In my earlier blog post, I had those 
    values less well constrained.
    
    The diagram makes very clear that this was the intended constellation over the 
    full past 8 years.
    
    In the diagram, you can neatly see that satellites switch from the primary to 
    the secondary orbital plane once a replacement is launched into the primary 
    orbital plane. In the West plane, USA 129 does this after the launch of USA 186. 
    In the East plane, USA 161 does this after the launch of USA 224 (it did so more 
    abruptly than USA 129 did over 2006-2008).
    
    So if we loose USA 186 over the winter, we should look for it in a plane 10 
    degrees west of the primary West plane (by then taken up by USA 245).
    
    The analysis also suggests that USA 116 ran out of fuel in 2006 and started to 
    drift, and was de-orbited in 2008 when it drifted too far from the intended 
    orbital plane.
    
    - Marco
    
    
    -----
    Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.
    e-mail: sattrackcam@langbroek.org
    
    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
    Station (b)log: http://sattrackcam.blogspot.com
    Twitter: @Marco_Langbroek
    -----
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