RE: Possible reentry captured over Chile ?

From: Ted Molczan (
Date: Sat May 11 2013 - 00:01:16 UTC

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    Randy John wrote:
    > That appears to be too much debris for a satellite only 10 cm on a side.
    > Could this have been the upper stage?
    An excellent observation. I had not paid much attention to this launch, so was unfamiliar with the payloads. I had noted
    that the object that decayed (13016D / 39145) had a large RCS value, so was confident that it could account for the
    impressive re-entry light show, but was unaware that its assigned name was that of a microsat payload. Upon further
    review, it is clear that (13016D / 39145) is the Cygnus Mass Simulator, not the microsat named Bell.
    Cygnus was the primary payload. Its specifications are listed here:
    Length = 199.24" = 5.06 m
      Dia. = 114" = 2.9 m
      Mass = 3800 kg
    I estimate that its mean cross-sectional area was 14.1 m^2. That yields area to mass ratio of 0.0037 m^2/kg, which is
    typical for a large primary payload. The A/m of rocket bodies typically is several times greater. Microsat A/m is likely
    to be greater still.
    The four microsats would have been expected to decay first, followed by the rocket, then the primary payload Cygnus. The
    four objects that decayed during 2013 Apr 26-27 UTC must have been the microsats. The rocket is correctly listed as
    having decayed on May 01 UTC.
    USSTRATCOM's RCS value for 13016D is similar to the mean cross-sectional area I estimated, and it was the largest object
    of the catalogued pieces. That leads me to conclude that 13016D is Cygnus. Since Cygnus was the primary payload, it
    correctly received the "A" designation, but the wrong orbit was assigned to that designation. It will be interesting to
    see whether and how USSTRATCOM attempts to correct the record. Regardless, we can be confident that the object that
    decayed on May 10 UTC was Cygnus.
    Ted Molczan
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