Re: Re: Lacrosse 2 may have been de-orbited

From: alain.figer@club-internet.fr
Date: Sat Apr 02 2011 - 10:44:16 UTC

  • Next message: Marco Langbroek: "COR: SATOBS ML (4353), 1 Apr 2011: USA 186, Lacrosse 4"

    I have taken several nice photos of bright satellites on 28 Mar 2011.
    I was then unaware of the Seasat-L info about Lacrosse 2, while Lacrosse 2 was one of my targets ot that night. 
    I expected it would pass near Alpha Auriga from 19h49m20s to 19h 49m30s UT (according to the chart of Heavens-Above).
    No satellite was visible to the naked eye, nevertheless I took as planned a 15-sec exposure of a wide field including a large part of Auriga constellation. After careful examination of the star field I was amazed to have recorded nothing across it (even a faint satellite at mag 6 would have been easy to spot though). I commented this photo with : "unexplainably failed attempt at Lacrosse 2".
    Due to the fact I was taking a photo of ERBS in Leo at 19h48.0m, I began watching for Lacrosse 2 pass just few seconds before 19h49.0m.
     
    Alain Figer, 
    near Paris, at:  Lon: 2°.128 E Lat: 48°.673 N  ; 170m a.s.l.
    
    
    ========================================
    
    Message du : 01/04/2011
    De : "Marco Langbroek " <marco.langbroek@wanadoo.nl>
    A : "Ted Molczan" <ssl3molcz@rogers.com>, "satelliet lijst (SeeSat)" <SeeSat-L@satobs.org>
    Copie à : 
    Sujet : Re: Lacrosse 2 may have been de-orbited
    
    
    
    
    I did a photographic search this evening (1 April), doing a continuous shoot 
    between 19:44:00 and 19:53:00 UTC of an 18 x 24 degree area centered on the 
    nominal position for 19:47:30 UTC. The pattern was: 10 seconds exposure, 10 
    seconds pause, and next 10 seconds exposure, etc...
    
    No sign of Lacrosse 2. Lacrosse 4 on the other hand, passing through the same 
    area around 19:46 UTC, was captured on several images. So Lacrosse 2 indeed is 
    gone, unless it passed before 19:44 UTC.
    
    - Marco
    
    
    
    Op 1-4-2011 20:32, Ted Molczan schreef:
    > I now believe that Lacrosse 2 (91017A / 21147) made at a major orbit manoeuvre, probably to de-orbit, in the early hours
    > of 2011 March 26 UTC.
    >
    > Pierre Neirinck reports that he observed Lacrosse 2 on Mar 25 at 20:19 UTC. It was on a near overhead pass, and reached
    > magnitude 2. He was unable to identify his reference stars, so had no positional data to report. It was a no-show for
    > him on March 28, but he allowed little margin for early arrival, so if it had lowered its orbit, it could have passed a
    > bit before he began observing.
    >
    > Another observer has reported off-list, that Lacrosse 2 was a no-show on March 26, to a high degree of confidence.
    
    > Ted Molczan
    
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