NROL-20 search elements

From: Ted Molczan (
Date: Tue Oct 18 2005 - 00:14:05 EDT

  • Next message: Robert Holdsworth: "Orbital Debris Quarterly News"

    NROL-20 - the final Titan-IV - is scheduled for launch from VAFB on 2005 Oct 19
    at 18:04 UTC.
    The launch time and azimuth indicate that the western KeyHole orbital plane is
    the target.
    Assuming the same launch trajectory as the previous KeyHole (USA 161 / 01044A /
    26934) the Titan 2nd stage and payload would enter the following parking orbit:
                                                            175 X 1029 km
    1 72001U          05292.79844637  .00807205  00000-0  10000-2 0    04
    2 72001  97.8760 354.5813 0611200 101.3444 265.7048 14.87728598    06
    Initially, the payload would trail by a short distance; within a day or two of
    launch, it would raise its perigee by about 100 km.
    The argument of perigee could differ somewhat. If the intention is to match that
    of the current occupant of the target plane (USA 129 / 96072A / 24680), then the
    argument of perigee would be 117.3 deg.
    I note that the down-range impact point of the 1st stage is nearly 700 km less
    than that of the previous KeyHole. Its range to impact is similar to that of USA
    144 (aka Misty 2). I am not certain what to make of that.
    Note also the report some time ago that the fairing is 10 ft longer than those
    of past KeyHoles (and 26 ft longer than USA 144's). So, I may post some
    alternative search elements.
    Assuming that the above orbit is correct, then South Africa will have passes
    within a few hours of launch, followed some time later by New Zealand and
    Ted Molczan
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:

    This archive was generated by hypermail 2b29 : Tue Oct 18 2005 - 00:23:16 EDT