re;STS78 STRANGE OBSERVATION
Maley, Paul D. (PMALEY@GP808.jsc.nasa.gov)
Sun, 30 Jun 1996 09:44:17 -0500
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
2.
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
pmaley@gp808.jsc.nasa.gov