RE: unid LEO

From: Ted Molczan (
Date: Sun Jul 04 2004 - 22:13:29 EDT

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    Ed Cannon wrote:
    > Last night after TOPEX and before ATEX, when I looked for 
    > Landsat 5, I saw one going in a different direction (pretty 
    > much straight down).  This weekend I'm house-sitting in 
    > Dripping Springs, Texas (30.190N, 98.086W, 275m).
    Do you have access to a GPS receiver? I would be helpful to have precise
    >  Findsat 
    > using alldat.tle yields no good match.  
    Nor does IDSat.
    The object traversed about 9 deg in 14.5 s, for a mean angular velocity of 0.62
    deg/s - pretty fast, and that was below 45 deg elevation.
    I fit circular orbits of 73 deg and 273 km; and 71 deg and 258 km. However, the
    altitude would have to have been over 500 km, to be clear of Earth's shadow.
    High altitude and high angular velocity are indicative of a highly elliptical
    orbit. Assuming perigee at your latitude, I tried various combinations of
    eccentricity and mean motion, but even Molniya orbit dimensions did not yield
    sufficient angular velocity over the observed arc.
    Do you recall approximately where you first saw it? Was it before or after
    maximum elevation?
    Normally, an unpublished, quasi 65 deg Molniya orbit suggests something related
    to the U.S. SDS, Jumpseat or Trumpet programs, except that the perigee should be
    well into the southern hemisphere, near 63 deg S.
    I vaguely recall that there may be some extremely elliptical, high inclination
    orbits that are not secret, but that may not be updated very often. I could be
    I look forward to any refinements you can offer to the site coordinates and/or
    object's coordinates.
    Ted Molczan
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