Thanks to Glenn Talbert's post yesterday, I now understand that the start and end of waste water dumps are denoted in the flight plans using the mostly opaque terms SIMO INIT and SIMO TERM. Here are the currently scheduled waste water dump periods for the remainder of STS 107: Date UTC Jan 22 17:45 to 19:05 Jan 26 02:40 to 04:10 Jan 28 17:25 to 18:55 Jan 31 04:35 to 05:40 A waste water dump is visible to the unaided eye as an illuminated plume extending from the shuttle, creating a surreal looking comet. The water freezes into ice crystals which reflect sunlight, so the phenomenon is visible only when the plume is in sunlight, and the observer in darkness. Please note that in the flight plan, the start and end times appear to fall within a 15 min range. This may have more to do with having to providing sufficient space to print the words SIMO INIT and SIMO TERM. In any case, the above start times are the earliest shown and the end times are the latest shown. A quick look at the above schedule and the shuttle's predicted ground track indicates that North American observers will not see any of the dumps. On Jan 22 and 28, South Africa will have passes during water dumps, but both occur near sunset. The orbiter should be visible, but the plume is likely to be too faint to be seen against the bright sky. On Jan 31, The Mediterranean should have a great view of the final water dump when the shuttle emerges from eclipse at about 05:08 UTC. For example, Rome's pass will culminate about 40 deg in the south. Observers elsewhere on Earth should run predictions to determine whether or not they will have favourable passes during the above periods. Always use the latest shuttle elements, in case it manoeuvres. Also, please be aware that the water dump schedule could change. The schedules are available here: http://spaceflight.nasa.gov/shuttle/timeline/index.html Ted Molczan ----------------------------------------------------------------- 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
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