RE: Elsets reqd for USA 59 + USA 72

From: Ted Molczan (
Date: Tue Sep 19 2000 - 09:16:33 PDT

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    Those objects are not part of the NOSS triads with which they were launched.
    I do not have current elements for either object; however, I have reason to
    believe that they have the same inclination as the NOSS orbits, 63.4 deg, but
    with approximately 1200 X 11600 km altitude, and with argument of perigee close
    to 270 deg.
    The objects are not currently tracked by hobbyists; however, USA 72 was
    discovered by Russell Eberst on 1992 Jan 09, and successfully tracked by
    himself, Pierre Neirinck and Peter Wakelin until 1992 May 04. Pierre reported
    it as missing on 1992 May 05, which I believe to have been the date of its
    manoeuvre to the high orbit.
    Although the object was near the orbital plane of the NOSS 2-2 triad, at the
    time, its exact identity was uncertain. Complicating matters, there was another
    unknown NOSS-like object being tracked in nearly the same plane, also
    discovered by Russell. What I am now calling 91076A, was called 9107600 in
    early 1992.
    Here are its last known elements:
    SLDCOM 2         5.0  0.0  0.0  6.2 v
    1 21775U 91076A   92125.13805590 -.00000117  00000-0 -16288-3 0    07
    2 21775  63.4357 126.8731 0014859 353.3635   6.5711 13.57324027    09
    The standard magnitude was derived from Russell's many observations, so it is
    quite accurate.
    I believe that the name SLDCOM derives from the fact that these are
    COMmunications satellites that piggy-backed on the SLD (aka Satellite Launch
    Dispenser) (aka TLD = Titan Launch Dispenser)), the small, specialized upper
    stage that deploys the members of the NOSS triads.
    Additional information on SLDCOM is available on the Federation of American
    Scientists' web site:
    These objects might be detectable by southern hemisphere observers using 11 X
    80 binoculars, but it would be a very difficult and time consuming search, with
    little certainty of success.
    Ted Molczan
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