From: Jonathan T Wojack (tlj18@juno.com)
Date: Fri Mar 29 2002 - 20:28:05 EST

  • Next message: Mir16609@aol.com: "Re: Observations - Shenzhou 3 + Shenzhou 3 Rocket"

    On 3-29 (UT), I went outside to look for Shenzhou 3 (~0012 UT; 27397) and
    its decaying rocket (~0021 UT; 27398).  They were not visible in a
    twilight sky, armed with 7x35's.
    On 3-30 (UT), I went outside to see the Shenzhou 3 rocket at ~0008 UT. 
    This time, I was successful.  It was to make a high pass (~80 degrees
    elevation), and I made a mad dash to get a chair out.  I took my glasses
    off and hoisted my 7x35's 5 seconds before its maximum elevation.  Before
    putting my eyes to the eyepieces of the binoculars, I saw something
    bright moving through the bright twilight sky - the Shenzhou 3 rocket. 
    It was about +1 at its peak, and dimmed to about magnitude +2.  Its flash
    period was about 15 seconds.  That estimate is made by counting aloud
    (One-one thousand, two-one thousand, etc.) to 15.  I probably should have
    put my glasses on instead and made a stopwatch timing (my watch is
    strapped to my wrist).  The entire flight was visible, naked-eye. 
    According to SatEvo, and the latest TLE, the rocket will be decaying on
    02093.4800 (2002 April 3).  About 48 hours earlier, that figure was
    02092.9414 (2002 April 2).  So, it would appear that after two days of
    orbital evolution, the Shenzhou 3 rocket will be staying up there another
    12 hours, i.e., its orbit is not decaying as fast as expected by the
    I just saw the main spacecraft hauled into orbit by the aforementioned
    rocket, Shenzhou 3, at about 0032 UT.  It was also visible at naked-eye,
    with a visual magnitude of about +2.  I was so pleased to be able to see
    it.  We were supposed to have rain tonight and Saturday night, and clouds
    on Sunday night, so I knew that after last night's failure, my prospects
    for seeing the historic spacecraft was in doubt.  But I saw it! 
    Thankfully, it was not tumbling or anything like that.  Both the rocket
    and the service/orbital module were on time.  As far as I can tell, the
    orbital module has not been released yet.  It has a planned 6 month
    orbital lifetime.  If it is of any relevance, Shenzhou III will decay
    from its present orbit in about 722 days.  Of course, it'll probably be
    back down on the Earth in about 1% of that.
    Two down (Shenzhou III and its rocket), one more (orbital module) to go.
    I set the standard magnitude of 27397 at +3.5, and 27398 at +4.0 in my
    Satspy visual magnitude config file.  The results tonight was that 27397
    was ~1.1 visual magnitudes fainter than expected, and 27398 was ~0.6
    visual magnitudes fainter than expected.  I changed those numbers to both
    +4.5, and I get +1 for 27398, and +2 for 27397.  So, I think +4.5 may be
    close to the real standard magnitude.  27398 had been estimated by RADAR
    cross-sectional analyisis to be +4.0.
    Jonathan T. Wojack                 tlj18@juno.com
    39.706d N   75.683d W            5 hours behind UT (-5)         
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