RE: Columbia water dump

From: Willie Koorts (
Date: Fri Jan 24 2003 - 07:26:30 EST

  • Next message: Peter Wakelin: "SATOBS 2003 January 23"

    Hi Fellow water-dump-fans
    In order to aid Ted's research into water dump dynamics, here's some old 
    messages after my first water dump observation.
    ---------- Forwarded message ----------
    Date: Fri, 28 Jun 1996 19:47:25 +0200 (GMT+0200)
    From: Willie Koorts <>
    Hi Folks
    I just had the most amazing sight of STS-78.  It was a very good pass, 
    practically overhead (61 deg.) 1 hour after sunset.
    The conditions were very favourable,  clear from horizon to horizon and 
    excellent sky transparency - the site is the observing outstation of the 
    South African Astronomical Observatory.
    At the predicted time at about 15 deg. elevation a little white cloud
    appeared.  While still scanning the skies in that direction,  we noticed 
    some movement towards us of this "white cloud".  The movement become 
    faster and much more noticeable and a bright spot started appearing on 
    the southern end of the cloud.  This light spot became possibly 1 st Mag 
    by the time of culmination and the "tail" was easily 2 degrees long at 
    this stage.  By now the 3/4 moonlight was becoming a nuisance but the 
    "tail" was almost all the way visible till shadow.
    The appearance of it was exactly like a lower case "j" on it's side with 
    the dot being the shuttle and the character the "tail".  We were 2 
    persons sighting it and we both remember the kink in the tail in 
    different directions.  The cloud was fanning open away from the shuttle.  
    Something like this: (Let's say the kink was towards the direction of 
                     Direction of movement.
    ---------- Forwarded message ----------
    Date: Sat, 29 Jun 1996 00:36:11 +0200 (GMT+0200)
    From: Willie Koorts <>
    On Fri, 28 Jun 1996 wrote:
    > Since there was not a time posted, I can say that today this particular
    > supply water ejection began around MET 8d 01h 06m and ended at 8d 02h
    > 23m. If I did not make a mistake in doing the conversion to UT, this
    > corresponds to June 28 at 17:55 UT and ended at 19:12 UT. Either way, I
    > checked the ground track map and it shows the orbiter passing over
    > Namibia on an ascending track at the time.
    > Paul Maley
    Sorry for leaving out one of the most important parts of reporting 
    anything.  Here is a copy of the predictions ala Greg Roberts: 
    (elems slightly old)
     For station  Sutherland at West Longitude =  339.19 and latitude =  -32.378
     Schedule for 96036A  #23931 on  960628 Age=   3.84 days  96036A
         UTC     AZM     EL    RNG   HGT    R.A     DEC   PHA  DMAG
      16:39:40  290.6    0.2  1859   272V  31:17   17:11  110  70.6
      16:40: 0  290.3    1.4  1718   271V  31:21   16:11   92   8.2
      16:40:20  289.9    2.9  1576   271V  31:25   15: 3   91   4.5
      16:40:40  289.4    4.4  1435   271V  31:30   13:47   90   3.1
      16:41: 0  288.8    6.2  1294   271V  31:35   12:19   88   2.4
      16:41:20  288.1    8.2  1154   271V  31:40   10:36   87   2.0
      16:41:40  287.3   10.6  1015   271V  31:47    8:29   86   1.7
      16:42: 0  286.1   13.6   877   271V  31:54    5:50   84   1.5
      16:42:20  284.4   17.4   742   271V  32: 3    2:21   83   1.4
      16:42:40  282.0   22.6   610   271V  32:15   -2:29   82   1.2
      16:43: 0  277.9   30.0   486   270V  32:33   -9:39   80   1.1
      16:43:20  269.7   41.5   376   270V  33: 1  -20:59   79   1.1
      16:43:40  247.6   57.8   298   270V  33:58  -38:38   78   1.1
      16:44: 0  185.8   64.5   278   270V  36:17  -57:39   76   1.1
      16:44:20  145.3   48.9   329   270V  39:44  -59:19   75   1.1
      16:44:40  132.4   34.5   425   270V  41:30  -50:37   74   1.3
    Hmmmm..  Our times does not exactly agree.  Is your information from NASA's
             official schedules?
    Two more questions:  How are these MET timings reckoned?
                         How long does such a dump normally take to sublimate 
                         and become invisible?
    ---------- Forwarded message ----------
    Date: Fri, 28 Jun 1996 20:14:50 -0500
    From: Mike McCants <>
    Subject: reply
    >How are these MET timings reckoned?
    Launch for STS 78 was 10:49EDT on June 20 = 14:49UT on June 20.
    Add Mission Elapsed Time to that to get actual time.
    Say hello to Greg.
    ---------- Forwarded message ----------
    Date: Sat, 29 Jun 1996 00:02:38 -0500
    From: "McDonald, Teresa A." <>
    To: Willie Koorts <>
    Hi Willie,
    According to the logs in Mission Control, that was indeed a water dump. The 
    shuttle is operating normally. I guess the light reflected off it in an 
    unusual way, causing the vapor to shine so brilliantly. I can't explain the 
    unusual "j" shape; perhaps the orbiter was using an RCS thruster to change 
    attitude and the vented water caught a "breeze."
    Here are the facts, according to my contact in Flight Design and Dynamics:
    A water dump took place from UTC 180/15:55 through 180/17:12.  This is
    from 5:55 pm to 7:12 pm South Africa time. Your sighting was at about 6:45pm.
    Best wishes,
    Terry McDonald
    ---------- Forwarded message ----------
    Date: Sun, 30 Jun 1996 09:44:17 -0500
    From: "Maley, Paul D." <>
    The observation Willie Koorts made was definitely a water dump. I did make 
    an error in my quick conversion from MET to UT as I was in a hurry at the 
    time. The water dump time began at 180days 15h 55m and ended at 17h 12m UT. 
    There was also a Flash Evaportor System (FES) core flush done earlier but it 
    was out of the scope of your observation.
    Explanation of the "j" shape is not what was forwarded to you by T. 
    McDonald. In fact, the "j" shape is easily explained by the vertical 
    orientation of the dump toward the earth. As water is propelled downward, 
    the particles farthest down from the orbiter speed up in the forward 
    direction. This is the same effect of ejecting a small satellite downward. 
    Each water particle becomes a small satellite. In a lower orbit it will 
    naturally accelerate faster than the orbiter. I first observed this about 12 
    years ago and have a brief video of that which I will be showing at EUROSOM 
    The water dump particles freeze upon ejection into space, are dumped and
    spread out in a continuous stream which in the past have actually been
    seen (by the cockpit crew) on one occasion to recontact the orbiter. They
    can last a number of orbits before decaying.  I was the originator of a
    Detailed Test Objective a number of years ago after observing the vastness
    of the water dump since it is indeed many kilometers long. This was not
    known until I observed it way back then. Since that time others have
    observed water dumps and describe varying lengths and appearances. They
    are always interesting to see and under a dark sky with no haze, clouds,
    moon, etc. give the impression of a small moving comet.
    Paul Maley
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