RE: More DSP-F23

From: Fred Valcho (
Date: Sat Dec 06 2008 - 00:31:44 UTC

  • Next message: Bob Christy: "Re: More DSP-F23"

    I found this! Feel free to scream when you read it.
    -----Original Message-----
    From: Greg Roberts [] 
    Sent: Friday, December 05, 2008 12:20 AM
    Subject: More DSP-F23
    Morning all
    The saga of DSP-F23 continues. Lets summarize briefly what the amateur
    network knows:
    DSP-F23 did not perform its October 2008 manoeuver. Observations made by
    the amateur network stations that can observe it ( Paul Wakelin in the
    UK and myself in South Africa) showed that DSP-F23 started drifting in
    mid-September 2008.
    An undisclosed source reports that radio transmissions failed around
    this time. During routine monitoring of transmitting classified
    satellites above my location on the 6th Nov 2008 I could find no signals
    from DSP-F23 on the usual frequencies.
    On the 25th Nov 2008 I asked Paul Marsh in the UK - the only other
    amateur station that had access to DSP-F23 and could receive such radio
    transmission -to check my observation of Nov 06,2008. This he did and
    reported reasonable signals. I then checked again on 26th Nov 2008 and
    found signals on the appropiate frequencies which I put down to coming
    from DSP-F23 but commented that they were somewhat weaker then
    News reports now surfacing state that all transmissions ceased in
    September and the satellite was uncontrolled, so this raises the
    question as to what Paul and I heard if the satellite was totally dead.
    There the matter rested until 03 December 2008 when I found a bright
    slow moving geostationary slowly pass DSP-F23 whilst getting positional
    observations on DSP-F23. I immediately recognised that it was a "new"
    object as the prediction program I was using - HEAVENSAT - had a
    database of over 12000 orbital elements and was giving a real time
    display of objects in the field of view. I thus followed the satellite
    at regular intervals for the next four hours and from this a preliminary
    orbit was determined.
    On the 4th December 2008 I again tracked this new object for another 3
    hours which will enable an accurate orbit to be determined. At the time
    of writing this the object appears to be very near, if not,
    geostationary with an inclination of about 6.5 degrees. Like on the 3rd
    December 2008 it passed very close to DSP-F23 - in fact almost occulted
    it on the 4th December 2008.
    Now Paul and I regularly observe this part of the sky and I am sure that
    we would have spotted this object a long time ago if it had been at this
    location for any reasonable length of time.
    Now I speculate and play "James Bond":
    It is my current belief ( I could be totally wrong!!) that this
    satellite was recently moved from its old position to a new position
    close to where
    DSP-F23 was stationed. This might explain the signals Paul and I heard
    on the 24/25th November 2008 which we thought were coming from DSP-F23.
    Now as to its possible identity. The amateur tracking network knows were
    all the DSP satellites are stationed and has derived recent elements (
    less than about one month old) for all of them except for DSP-F20 which
    has not been observed for several months and DSP-F22 which is out of
    range to the amateur radio/optical network. DSP-F20 was drifting when
    last observed and is currently visible from the United States area so
    observations are needed, so this only leaves DSP-F22 as a possible DSP
    I do not believe so for the following reasons:
    The new object - for the moment called 91128 - is a lot brighter than
    When it almost occulted DSP-F23 it was about two magnitudes brighter
    under the same phase-angle conditions. In addition during the 8 hours
    total that I have observed this object I have seen no typical DSP
    flashing nor any variation in magnitude other than that due to phase
    angle variation. I am using integrated images where the satellite is
    recorded as a trail so its difficult to detect flashing but the traces
    appear perfectly uniform.  
    DSP-F20 had an inclination of 4.08 deg in early 2008 so might be as much
    6.5 degrees now (?). It was still in service March 2007 so is the
    drifting orbit last observed a drift to a new location or that of a
    graveyard orbit ?
    DSP-F22 has an inclination too low to reach the 6.5 degrees required now
    to match the new object.
    So, at the moment I do not think this is a DSP so how does one explain
    the signals heard on the frequencies used by DSP satellites ?
    I do however believe that the object now being observed is almost
    certainly an operational spacecraft - it is far too bright to be a piece
    of debrii and the lack of optical variation would indicate that it is
    To conclude :  has the saga of DSP-F23 reaches its end yet ?
    Maybe all this James Bond speculation will be destroyed if we find that
    91128 is nothing but a drifter than happened to pass DSP-F23 ?
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