Cosmos 2282 for 9/13 (UT)

From: Matson, Robert (ROBERT.D.MATSON@saic.com)
Date: Fri Sep 13 2002 - 18:40:12 EDT

  • Next message: Daniel Deak: "NOSS 2-3 naked eye obs by 8-year old !"

    Hi All,
    
    Thursday night 9/12 (PDT) was another clear night so I decided
    to go after Cosmos 2282, ASC 1 and Gorizont 15.  The latter two
    were not visible at 9/13 04:40 UT, but Cosmos 2282 was flashing
    very dimly at around mag +7 at its brightest.  Many flashes were
    not visible (limiting magnitude +8.3).
    
    By 05:00 UT, Cosmos 2282 was still dim but I went ahead and
    started a timing sequence on it.  Still nothing from ASC 1
    or Gorizont 15.
    
    At ~05:50, I stopped my first timing run on Cosmos 2282 and
    concentrated on the others.  Still nothing.  C2282 was flashing
    much better at this time -- about +5.5, and no invisible flashes.
    At 06:16 I went ahead and started a second timing run on it.  By
    now the flashes were regularly +5 or brighter, with some to +4.
    
    Called it quits at ~06:44.  Still nothing from either ASC 1 or
    G15.  My two C2282 timings:
    
    From Newport Coast, CA [33.6028 N, 117.8263 W, 200m]
    COSPAR # 8733
    
    Cosmos 2282 (#23168):
    94- 38A 02-09-13 05:49:32.4 RM 3134.23 0.05 151 20.7565 +5.5/+7 --> inv
    94- 38A 02-09-13 06:43:51.3 RM 1660.51 0.05  80 20.7564 +4/+5 --> inv
    
    The combined measurement is:
    94- 38A 02-09-13 06:43:51.3 RM 6434.50 0.05 310 20.7565 +4/+7 --> inv
    
    This is a period decrease of 0.01161 seconds in the last day.
    This means that if the spin up was at a steady rate, the expected
    hourly decrease would be ~.00048 seconds.  This is about the same
    as my measurement uncertainty, so not much can be gleaned from
    my two measurements roughly an hour apart.  With a 3-hour span,
    it should be possible to detect whether or not the acceleration
    matches the expected hourly rate.  I'm guessing it won't -- that
    when the satellite is sunlit the spin-up is much slower than this,
    and that most of the acceleration occurs during the ~65 minutes
    of eclipse the satellite experiences each night at this time of
    year.
    
    --Rob
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Fri Sep 13 2002 - 18:57:01 EDT