RE: Search elements of suspected Helios 2B-related UNID

From: Ted Molczan (
Date: Thu Aug 26 2010 - 21:27:32 UTC

  • Next message: Allen Thomson: "Re: Search elements of suspected Helios 2B-related UNID"

    Patrick Schmeer asked:
    > > Are there any other bright satellites in
    > > sun-synchronous orbits that are missing?
    Helios 2B (09073A / 36124) remains to be found, but that is only a matter of time.
    > Or, more generally asked, which missing/lost
    > classified satellites may be still in orbit
    > (LEO in particular)?
    A small number of LEO objects are missing or lost, mainly because they are faint.
    Marco Langbroek pointed out that Misty 2 (99028A / 25744) may still be in orbit. Even Misty 1
    (90019B / 20516) could still be in orbit. Those are intentionally faint, and have been (mostly)
    successful at eluding our detection.
    We lost track of Geosat FO (98007A / 25157) and XSS-11 (05011A / 28636) after they manoeuvred into
    long-term disposal orbits (lowered perigee). They are not extremely faint, and we have sufficient
    data to construct reasonable search orbits, so I suspect they could be found with some effort.
    Eventually, they will be spotted as UNIDs. (When UNIDs are reported, we check for consistency with
    the plane of missing/lost objects.)
    A couple of small, faint, ferrets launched with KH-9 satellites, 80052C / 11852 and 83060C / 14139,
    have not been seen since 2007.
    A couple of NOSS plume shields that served as payloads, are in orbit. They are known as LIPS (Living
    Plume Shield). Lips 2 (83008B / 13792) has not been reported since the late 1980's. Lips 3 (87043B/
    17998) was observed during 1999-2000. They are faint.
    To my knowledge, hobbyists have never (knowingly) observed the three small payloads of the 90031A /
    20560 launch; the rocket body was observed during 1999-2001.
    Those are the ones that come to mind immediately.
    Ted Molczan
    Seesat-l mailing list

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