Decay watch: 2003 April 30 - BeppoSAX down

From: Alan Pickup (alan@wingar.demon.co.uk)
Date: Wed Apr 30 2003 - 03:51:23 EDT

  • Next message: Leo Barhorst: "Obs Apr 29"

    BeppoSAX is down but there is uncertainty as to just when and where. The 
    following is my entire note on this, lifted from my Decay Watch page:
    _____________________________________________________________________
    Object: #23857 = 96- 27 A = BeppoSAX
    Beppo Satellite per Astronomia a raggi X
    Italian-Dutch X-ray astronomy satellite launched on April 30, 1996.
    It was switched off on April 30, 2002 and will make an uncontrolled
    reentry.
    (Diameter : 2.7 m   Length : 3.6 m   Launch mass : 1400 kg)
    
    Notice prepared: 2003 Apr 30 06:55 UTC
    
    Decay predictions:
    Source   Prediction made    Predicted decay at      Latitude Longitude
                    UTC                UTC                  deg      deg
    
    SCC        Apr 26 09:45     Apr 30 09:56 +-2d         3.9 N    70.3 E
    SCC        Apr 26 15:23     Apr 29 11:35 +-2d         2.0 N     1.7 W
    SCC        Apr 27 23:50     Apr 29 19:29 +-1d         1.9 N     3.9 W
    SCC        Apr 28 19:27     Apr 29 14:18 +-12h        3.0 S   124.2 W
    SCC        Apr 29 14:38     Apr 30 02:57 +-9h         0.0      90.5 W
    SCC        Apr 29 20:49     Apr 29 22:18 +-1h         3.8 N    91.5 W
    SCC        Apr 29 22:47     Apr 29 22:01 +-7m         4.0 N   130.0 W
    
    SatEvo     Apr 26 18:20     Apr 30 14:55 +-1.2d
    SatEvo     Apr 27 17:25     Apr 30 08:20 +-19h
    SatEvo     Apr 28 19:15     Apr 30 05:35 +-12h
    SatEvo     Apr 29 19:00     Apr 30 02:45 +-5h         2.0 N   118.1 W
    SatEvo     Apr 30 06:55     Apr 29 22:25 +-70m        1.4 N    40.7 W
    
    Final elsets:
    BeppoSAX                                         195 x 191 km
    1 23857U 96027A   03119.48066962  .06986978 -36857-4  14226-2 0  6513
    2 23857   3.9524 357.0909 0002972 259.6479 100.3277 16.29956364386193
    BeppoSAX                                         169 x 169 km
    1 23857U 96027A   03119.78601475  .25031881 -37595-4  19941-2 0  6525
    2 23857   3.9525 354.3668 0000010 271.5083  89.2266 16.38867537386243
    
    Note: As I indicated in my previous note, fresh elsets and updated
    SCC predictions were slow to appear for this object. Indeed, the final
    two elsets and three predictions were all posted on the OIG site after
    my note yet the elsets themselves had epochs before it. The first elset
    shows BeppoSAX running 1.4 sec late on my own prediction, while the
    second has it 6.4 sec early. This behaviour indicates that drag
    increased much more quickly than expected, but probably in line with
    the higher geomagnetic and auroral activity over the latter part of
    the April 30.
    
    My own estimate is that this may have decayed over Brazil near the
    middle of the SatEvo-predicted orbit:
    BeppoSAX                                         142 x 141 km
    1 23857U 96027A   03119.90724435  .94057752  11975+2  13664-2 0 96527
    2 23857   3.9522 353.2596 0000705 273.7149  86.2770 16.49334592386267
    Unless further elsets appear, my window of uncertainty is more than
    one orbit wide, much less than SCC's (almost ubiquitous!) 7 minutes.
    
    I note that the latest analysis, Report #23 issued at 00:00 CET today, 
    on the BeppoSAX Reentry Page (http://www.asdc.asi.it/bepposax/reentry/) 
    gives an estimated decay window from 22:48 until 00:57 UTC, with nominal 
    impact at 23:36 UTC.
    _____________________________________________________________________
    
    
    Alan
    -- 
    Alan Pickup / COSPAR 2707:  55.8968N   3.1989W   +208m   (WGS84 datum)
    Edinburgh  / SatEvo Home Page:   http://www.wingar.demon.co.uk/satevo/
    Scotland  / Decay Watch: http://www.wingar.demon.co.uk/satevo/dkwatch/
              *
    
    
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