Preliminary NROL-39 search elements

From: Ted Molczan (
Date: Mon Dec 02 2013 - 22:06:33 UTC

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    NROL-39 will launch FIA Radar 3 (aka Topaz 3) on an Atlas V-501, from Vandenberg AFB, on 2013 Dec 06, near 07:00 UTC.
    I estimated the launch time based on the just-released Broadcast Warning message.
    The first launch in the series (10046A / 37162) also employed an Atlas V-501. The second (12014A / 38109) employed a
    Delta IV Medium+(5,2). The initial orbits were similar. Based on my guess that the differences were mainly launch
    vehicle specific, I am basing the present search elements on the those of the 10046A launch.
    Launch at 07:00 UTC would result in the following orbit:
    07:00 UTC launch                                      1067 X 1080 UTC
    1 78800U          13340.33736627  .00000000  00000-0  00000-0 0    04
    2 78800 122.9957 216.5582 0008930  69.2445 290.9476 13.49595610    09
    A couple of weeks ago, Cees Bassa reminded me that the first two FIA Radar orbits are almost precisely 180 deg apart in
    RAAN. Cees suggested that the present launch might target a plane midway between them. The above orbit falls reasonably
    close to that separation. Delaying the launch to 07:36 UTC would place the new orbit exactly midway between the first
    two in RAAN, with the following approximate elements:
    07:36 UTC launch                                      1067 X 1080 UTC
    1 78801U          13340.36236899  .00000000  00000-0  00000-0 0    04
    2 78801 122.9957 225.5838 0008930  69.2445 290.9476 13.49595610    04
    Immediately after the first two launches in the series, the second stage was de-orbited into the Indian Ocean. NROL-39
    carries secondary payloads, which may result in the second stage remaining in orbit. A re-entry hazard notification has
    yet to appear among the Broadcast Warnings.
    The above orbits would result in visible passes in the morning for northern hemisphere observers, and evening for those
    in the southern hemisphere.
    I will revise the search elements once I am confident of the actual planned launch time.
    Ted Molczan
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