RE: Orbital surveillance satellites now exceed 1 inch resolution?

From: Robert Clark (bobbygc2001@yahoo.com)
Date: Wed May 02 2007 - 09:43:51 EDT

  • Next message: Russell Eberst: "2007MAY1.OBS"

     Definitive proof would be given by telescope
    observations. This page shows images by a 1 meter
    scope of Mir and ISS at around 400 km altitude:
    
    Gallery - Artificial Satellites.
    http://www.tsm.toyama.toyama.jp/curators/aroom/satellite/index.htm
    
     These space stations are around 30 to 40 meters wide
    at their widest dimensions. So at 2000 km altitude and
    1/5th the size, the object in question would appear
    1/25th the size of the stations in these images. You
    could probably resolve its shape. Of course a 2 meter
    scope could do better.
    
    
    
       Bob Clark
    
    
    --- Ted Molczan <molczanssl@rogers.com> wrote:
    
    > Robert Clark asked:
    > 
    > > My reading of the discussion on the "Misty" type
    > satellites 
    > > suggests they are difficult to track visually.
    > > So how are these orbital elements so accurately
    > determined 
    > > to the degree that the amount of orbital decay
    > they are 
    > > experiencing can be determined?
    > 
    > The object in question is readily tracked because is
    > not a Misty satellite. It
    > is either debris or a decoy resulting from the
    > launch of what is now believed to
    > be Misty 2 (1999-028A / 25744), which was launched
    > in May 1999.
    > 
    > In June 1999, hobbyists began tracking an object
    > from that launch that was
    > fairly intrinsically bright, in a 63.4 deg, 2700 km
    > x 3100 km orbit, which
    > seemed like it might be the payload. Initial
    > speculation was that it was an
    > IMINT satellite of KH-11 lineage, sent into a higher
    > than usual orbit, to obtain
    > increased dwell-time and wider area coverage of
    > targets, at reduced resolution -
    > a need that had been identified as a result of
    > experience during Operation
    > Desert Storm. 
    > 
    > This theory began to fall apart in 2002, with the
    > discovery of the object's high
    > area-to-mass ratio, which makes it more likely to be
    > debris than a payload, as I
    > reported in the following post, which I believe you
    > have read:
    > 
    > http://satobs.org/seesat/Aug-2002/0045.html
    > 
    > In the above post, I also discussed the object's
    > other debris-like
    > characteristic: it rotates, unlike most payloads,
    > which are 3-axis stabilized.
    > 
    > Initially, its period of brightness variation was
    > about 150 s, which had
    > decreased to 116 s after three years. By the summer
    > of 2005, it had decreased
    > below 80 s; since then it appears to have been
    > increasing:
    > 
    >
    http://satobs.org/seesat_ref/99028C_period_of_var/99028C_period_of_var_3.jpg
    > 
    > If the object were a spin-stabilized payload, then I
    > would expect its rate of
    > rotation to remain much more nearly constant.
    > 
    > In late 2005, we changed our designation of the high
    > object from 1999-028A /
    > 25744 to 1999-028C / 25746, in recognition that it
    > could not be the primary
    > payload, and most likely is debris, or a decoy,
    > intended to draw attention away
    > from Misty 2, which most likely would have gone to a
    > quasi 65 deg, 700 - 800 km
    > orbit, like that of its predecessor.
    > 
    > We should have made the switch sooner, but finally
    > acted when it became clear
    > that using the original ID was creating confusion
    > among those not familiar with
    > the evolution of our understanding of this object.
    > 
    > Based on its observed brightness, 99028C probably
    > has a cross-sectional area of
    > about 50 m^2. Assuming it presents an equivalent
    > area to the sun, then its mass
    > is about 560 kg, based on its area-to-mass ratio of
    > about 0.09 m^2/kg, derived
    > from analysis of solar radiation pressure
    > perturbations.
    > 
    > For the object to be a primary Titan IV-B class
    > payload, it would have to be
    > very massive, and have a large surface area facing
    > the sun, to account for its
    > area-to-mass ratio.
    > 
    > I estimate that a manoeuvrable Titan IV-B payload in
    > excess of 10,000 kg (dry
    > mass) could reach the 63.4 deg, 2700 km x 3100 km
    > orbit of 99028C, which would
    > require a sun-facing surface area of about 900 m^2.
    > I cannot imagine an NRO
    > spacecraft so-configured.
    > 
    > The JWST (James Webb Space Telescope), has a mass of
    > 6200 kg, and a sunshield of
    > 220 m^2, resulting in a sun-facing A/m of 0.035
    > m^2/kg, well short of 99028C's
    > value. Of course, unlike NRO telescopes, JWST is
    > designed for ultra-high IR
    > sensitivity, requiring it to have the large
    > sunshield. Also, JWST is 3-axis
    > stabilized.
    > 
    > Ted Molczan
    > 
    >
    -------------------------------------------------------------------------
    > Subscribe/Unsubscribe info, Frequently Asked
    > Questions, SeeSat-L archive:  
    > http://www.satobs.org/seesat/seesatindex.html
    > 
    > 
    
    
    __________________________________________________
    Do You Yahoo!?
    Tired of spam?  Yahoo! Mail has the best spam protection around 
    http://mail.yahoo.com 
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:  
    http://www.satobs.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Wed May 02 2007 - 09:46:41 EDT