Re: 12044A / 38744: altitude increasing?

From: Bob Christy (bob@zarya.info)
Date: Sun Aug 12 2012 - 10:25:39 UTC

  • Next message: C. Bassa: "CB Obs August 11/12, 2012: w/ Helios 2A, HAPS, IGS 6A"

    A thought just hit me..... maybe 044D is NOT the APT.
    
    The Proton/Briz dual launch 2011-035 carried SES 3 & KazSat 2. 
    SpaceTrack catalogued three Briz-related items: Briz-M, the APT and what 
    it called "BREEZE-M DEB (ADAPTOR)". It could be that 2012-044C is the 
    APT and Briz-M still in one piece, and that the object with a more-rapid 
    decay is the 'adaptor' which would have a relatively-small mass to 
    cross-section ratio.
    
    In Kevin's video, the two brighter objects are then the Briz-M/APT at 
    the front of the train with the larger of the satellites (Telkom) at the 
    rear, and Express and the 'adaptor' in between.
    
    SpaceTrack did not catalogue an adaptor for the 2011-074 dual launch of 
    Amos 5 and Luch 5A. However, the commonality between SES/Kazsat and 
    Telkom/Express is that each of Kazsat and Express was built around a 
    part of the Briz-M satellite support structure so the mounting 
    arrangement for these two launches would be similar. This technique was 
    not used for the construction in the Luch/Amos pairing.
    
    Bob Christy
    
    
    On 11/08/2012 16:53, Ted Molczan wrote:
    > Bob Christy wrote:
    >
    >> In the light of SpaceTrack's switching around of IDs and increasing
    >> number of element sets published, I've revisited my reasoning as to
    >> which ID is which launch component. I agree with Ted but by have
    >> approached it from a different angle.
    >>
    >> I still think it is the APT that is venting fuel or gas:
    >> http://www.zarya.info/Gallimaufry/120707ProtonFailure.php
    > The following are preliminary estimates, with little error checking.
    >
    > Assuming the Breeze-M core carried its maximum of 5200 kg of fuel, then all of it should remain. Add to that its
    > approximate dry mass of 1420 kg, for a total of 6620 kg. I estimate that its mean cross-sectional area is about 5.31
    > m^2. A/m would be ~0.00080 m^2/kg.
    >
    > I estimate that at shut-down the APT still contained about 6538 kg of fuel. In an NSF forum, its dry mass was stated to
    > be 950 kg. Total mass would be 7488 kg. I estimate that its mean cross-sectional area is about 8.1 m^2. A/m would be
    > ~0.00108 m^2/kg.
    >
    > If objects 12044C and 12044D are the core and the APT, then the above A/m values suggest that their rates of decay
    > should be roughly the same. In fact, the C object has exhibited negligible decay for the past couple of days, and D has
    > exhibited a fairly high rate of decay since it reached orbit.
    >
    > Since C and D should be several times as massive as the payloads (12044A and B) and probably have no greater
    > cross-sectional area than A and B, I would expect both to have significantly lower rates of decay than A and B, but that
    > is true only of C. D has been decaying at 3 to 4 times the rate of A and B. Could that be because D is the APT, which
    > somehow has vented most of its fuel?
    >
    > As for C, there is room for doubt that its recent negligible rate of decay and fluctuations in mean motion are due to
    > fuel leakage. It may turn out to be due to unusually slow convergence to a realistic rate of decay. The situation will
    > become clearer as additional TLEs are released.
    >
    > Before hitting send, I checked Space Track again, and I found that they have now attached the following names:
    >
    > 12044A TELKOM 3
    > 12044B EXPRESS MD2
    > 12044C BREEZE-M R/B
    > 12044D BREEZE-M DEB
    >
    > Ted Molczan
    >
    >
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