USA 129 and 186 elements

From: Ted Molczan (seesat@rogers.com)
Date: Sat Oct 29 2005 - 14:25:36 EDT

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    Northern hemisphere observers last saw USA 129 on 2005 Oct 09 UTC. It had been
    expected to make a routine small re-boost as early as Oct 15. On Oct 28, South
    African observer Greg Roberts performed a planar search, and found the object,
    running about 28 min late relative its Oct 09 orbit, confirming that the reboost
    had taken place:
    
    http://satobs.org/seesat/Oct-2005/0268.html
    
    The following estimated elements should be reasonably accurate in the near term;
    the greatest uncertainty being in the mean motion:
    
    USA 129         15.0  3.0  0.0  5.3 v
    1 24680U 96072A   05301.80353066  .00011207  00000-0  15000-3 0    07
    2 24680  97.9602   3.3814 0525000  88.1723 277.9511 14.73500000    07
    
    On Oct 28, Greg also made his second observations of USA 186, launched on 2005
    Oct 19 UTC, into nearly the same plane as USA 129, which it is intended to
    replace. The following elements are a very good fit:
    
    USA 186         15.0  3.0  0.0  5.3 v                   261 X 1047 km
    1 28888U 05042A   05301.82157479  .00009787  00000-0  10000-3 0    05
    2 28888  97.8760   3.6534 0558690 154.6890 208.2851 14.71233989    03
    Arc 2005 Oct 25.82 - 28.88, WRMS residuals = 0.010 deg
    
    I used fixed estimates of decay rate and inclination; all other elements were
    permitted to vary. Increasing the inclination slightly, to 97.95 deg, resulted
    in a slightly less eccentric orbit: 265 X 1043 km. Additional tracking will
    yield a more precise orbit.
    
    USA 186's initial orbit is very similar to that of USA 129, per this example 29
    days after its launch:
    
                                                            262 X 1039 km
    1 24680U 96072A   97 18.85811921  .00006385  00000-0  65978-4 0    08
    2 24680  97.8745  84.2363 0552461  70.2327 255.0973 14.72378315    04
    
    Assuming that 95066A and 01044A remain in orbit, there are now a record-breaking
    four KH-11 class satellites in orbit at the same time.
    
    Ted Molczan
    
    
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