Re: The decay of the GLONASS launch objects

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Sun Dec 02 2001 - 10:54:09 EST

  • Next message: Vitek, Antonin: "Re: Possible re-entry"

    As Harro says, it appears that the object seen from S England and France 
    at ~22:35 UTC on December 1 is related to the decay witnessed from Texas 
    and Oklahoma a few hours later, around 04:18 UTC.
    
    The rocket concerned, a Proton or "SL-12", was launched from Baikonur at 
    21:04 Moscow time (18:04 UTC). It carried three global positioning, or 
    navigation, satellite: two Uragan ("Hurricane") satellites and a new 
    generation Uragan-M satellite. All three have now reached their 
    near-circular orbits at a height of 19,120 km, being catalogued by 
    SpaceCom as objects A, B and C from this launch. The fourth catalogued 
    object (D) is the Proton rocket, while a fifth object (E) is in a 
    similar orbit to A, B and C and is presumably the upper stage rocket (a 
    Blok DM-2?) that accomplished the final deployment of the payloads. Now, 
    what is missing is any mention of what SpaceCom usually call a 
    "Platform", actually a cylindrical casing that (I understand) shrouds at 
    least the lower part of the Blok DM during the launch. This is usually 
    shed when the Blok DM detaches from the Proton, being left in much the 
    same low orbit as the Proton from which it decays more rapidly because 
    of its relatively low mass:area ratio. It would normally be expected to 
    receive the object designation between the rocket and the Blok DM, so 
    (for this launch) I would have expected the Proton to be D, the 
    "Platform" to be E and the Block DM to be F.
    
    The fact that SpaceCom did not catalogue it, does not mean that casing 
    did not exist. Indeed, I think that this was the object seen to be 
    decaying as it tracked north-eastwards across N France towards Calais. 
    It would have been on its third orbit at the time and moving along much 
    the same track that the Proton itself may have taken:
    
      Time (UTC)    Lat     Long
       h  m  s    deg N      deg
    
      22 32  0     44.6      5.1 W
      22 32 30     46.2      3.5 W
      22 33  0     47.9      1.7 W
      22 33 30     49.4       .2 E
      22 34  0     51.0      2.1 E
      22 34 30     52.5      4.3 E
      22 35  0     53.9      6.6 E
      22 35 30     55.3      9.0 E
      22 36  0     56.7     11.7 E
      22 36 30     58.0     14.5 E
      22 37  0     59.2     17.6 E
    
    (Though the casing may have been a few seconds earlier and slightly 
    further E)
    
    The Proton survived for another for (almost) another four orbits before 
    its decay over the USA.
    
    
    Alan
    -- 
    Alan Pickup / COSPAR 2707:  55.8968N   3.1989W   +208m   (WGS84 datum)
    Edinburgh  / SatEvo & elsets:    http://www.wingar.demon.co.uk/satevo/
    Scotland  / Decay Watch: http://www.wingar.demon.co.uk/satevo/dkwatch/
              *
    
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