This is a fascinating clip, with many features of typical low-light Tv from the payload bay (the curving white line is the airglow layer, about 30
miles above the actual physical horizon -- that's why stars are still visible as they pass beneath it), but the long slow curving motion is unusual
[thruster firings are usually brief, and so course changes are o short duration]. Fortunately, in looking for any physical effect that might account
for a long-term force on a nearby moving object, we have the exact time of the video, and can access mission planning documents. Here's what we can
Europa733 wrote: “Orbit: 174 Met 010 23 11 Mission Elapsed Time: 10 days, 23 hours, 11 minutes. “
See in general www.nss.org...
And specifically www1.nasa.gov...
This is Flight Day 12, and MET 10/23:11 is the beginning of the crew pre-sleep activities, after a brief off-duty respite, and just immediately before
sunrise. They undocked from the space station six hours earlier. An attitude maneuver using vernier jets (from biased –ZLV +YVV to -ZLV –XVV
attitude) was scheduled for an hour later.
This activity is of high significance to the video. Water dumps often create sprays of ice particles, or just invisible water vapor flows across the
camera field of view.
11 Prior to the waste water dump scheduled at 10/20:45, pregather the following:
13 Leaking Technical Water CWC S/N 1012 (temp stowed after CWC Dump on
16 Shuttle Condensate CWC S/N 5050 (temp stowed after Shuttle Condensate
17 Collection Changeout on FD10)
19 Shuttle Condensate CWC S/N 6008 (temp stowed after Shuttle Condensate
20 Collection Teardown on FD11)
22 Waste Water Dump (WWD) Filter from the Shuttle BOB (MF14H)
24 CWC (Yellow-Yellow 20 ft) hose from Shuttle CHCK
26 At MET 10/20:45, perform a waste water dump using SUPPLY/WASTE WATER
27 DUMP (ORB OPS, ECLS), p. 5-2 Steps E, G, and I #1 and I #2. Dump the waste
28 tank to 5%. Nozzle open time will be ~37 minutes. MCC will TMBU all FDA limits.
30 After step I #2 of SUPPLY/WASTE WATER DUMP (ORB OPS, ECLS) is complete,
31 exit that procedure and begin dumping the remaining water in leaking CWC S/N
32 1012 starting in Step A DUMP PREP of CWC OVERBOARD DUMP (ORB OPS,
33 ECLS) p. 5-32. Do not perform steps B, C, and H. Sequentially dump CWC S/N
34 1012, Shuttle Condensate CWC S/N 5050, and Shuttle Condensate CWC S/N 6008.
35 MCC will TMBU all FDA.
37 Leaking CWC S/N 1012 dump duration will depend on how much water is left in the
38 bag, but should take no longer than 20 minutes. CWC S/N 5050 dump duration will
39 be approx. 63 minutes. CWC S/N 6008 dump duration will be approx. 16 minutes.
So the dump was expected to be complete at about 23:01 if it started on time and there was no time used between switching the different bags and
The particle moving linearly from left to right can be postulated as a member of the population of entrained ice particles from the tail end of the
water dump. The brighter particle originating on the right side of the screen, sunlit since the shuttle has passed out of Earth's shadow, is of
undetermined origin -- there are so many candidates aboard 'leaky' shuttles -- but in its motion is gently pushed by the same force that has
propelled the smaller particle left-to-right. Hypothesis -- it's the tail end of the water dump, as described in detail on the daily activity
The shuttle attitude, biased –ZLV +YVV, means the -Z axis into local vertical (i.e., payload bay to Earth, the most benign thermal orientation), and
+Y (out the right wing) into velocity vector (i.e., flying sideways into sunrise). This indicates the rising sun will illuminate anything floating up
and out of the payload bay.
RFBurns, you indeed know a lot about orbital mechanics -- much of it accurate, but much of it garbled. I'll get back to you