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Soyuz MS-22 & Progress MS-21 coolant leaks : Dec 2022 & Feb 2023
by
theonlyspace
on 15 Dec, 2022 01:20
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Any screen grabs of the venting from the Soyuz?
[zubenelgenubi: I created a stand-alone thread from split/merged posts for this incident. Please use this thread, at least for now, for both updates and discussion.]
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#1
by
cohberg
on 15 Dec, 2022 01:21
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#2
by
sdsds
on 15 Dec, 2022 01:33
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#3
by
sdsds
on 15 Dec, 2022 03:05
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NASA PAO (Rob Navias): coolant leak first observed 6:45 pm central time, indicated by a warning annunciator. Leak still under investigation. No news yet on forthcoming course of action.
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#4
by
sdsds
on 15 Dec, 2022 03:14
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#5
by
yg1968
on 15 Dec, 2022 03:17
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#6
by
sdsds
on 15 Dec, 2022 03:36
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NASA PAO describing view of extended European Robotic Arm between Rassvet and Nauka. Using arm to do inspection of Soyuz MS-22.
EDIT to add second image, and to note the ERA is being controlled by Anna Kikina.
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#7
by
hektor
on 15 Dec, 2022 04:19
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NASA has wrapped up their coverage.
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#8
by
hektor
on 15 Dec, 2022 04:22
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Does a coolant leak like this one potentially compromise the departure and EDL ability of the Soyuz MS-22 spacecraft?
Three possible answers :
1) No
2) Not for the time being but Soyuz MS-22 departure should be anticipated.
3) Yes. The Soyuz MS-22 must be disposed of, and a scenario must be generated to bring back its crew : launch of an empty Soyuz, launch of an empty Dragon, seven crew in Dragon, add empty seats in Starliner OFT vehicle, or other...
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#9
by
AS_501
on 15 Dec, 2022 04:27
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Hopefully the substance has not impinged on the USOS arrays. I think I heard Moscow say something about not using the cupola windows to inspect the leak, i.e. better to keep them closed while the leak persists.
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#10
by
Twark_Main
on 15 Dec, 2022 04:28
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Putting this here instead of the spacewalk thread, to stay on-topic. Thank you moderators for the new thread!
Some reports (eg
Ars) are speculating that the coolant is ammonia, presumably because it is used in the US orbital segment external loop (the internal loop uses water).
However note that the Russian designs have preferred to use silicone oil in the external loop (eg mentioned re:Mir
on page 43, but AIUI the ROS currently uses it) and water/glycol for the internal loop (see
page 7).
While ammonia will evaporate harmlessly (as it has in previous ISS ammonia leak incidents), silicone oil would not.
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#11
by
zubenelgenubi
on 15 Dec, 2022 04:59
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Moderator:
For the time being, please use this thread for the leak updates and discussion.
No off-topic crud or diversion into politics.
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#12
by
zubenelgenubi
on 15 Dec, 2022 05:01
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Member:
I really, really, really hope that the root cause was not MMOD damage from a too-small-to-detect-by-radar debris particle born in the Russian ASAT test.

What do we know about
Soyuz MS coolant leaks?
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#13
by
hektor
on 15 Dec, 2022 05:08
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I am not a big believer in coincidences but I cannot make the link between an EVA and a sudden leak on Soyuz.
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#14
by
Twark_Main
on 15 Dec, 2022 05:14
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Member:
I really, really, really hope that the root cause was not MMOD damage from a too-small-to-detect-by-radar debris particle born in the Russian ASAT test. 
What do we know about Soyuz MS coolant leaks?
I had the same thought. "What goes around comes around" (especially in orbit).
We know that Soyuz uses water/glycol for the internal ECLSS (see above), and
probably uses silicone oil for the external loop (though I haven't found a confirming source).
We'd better hope that it's not silicone oil leaking, because it has a nasty tendancy to
react with atomic oxygen in LEO to form solid silica, leaving behind permanent deposits which can foul external optics and sensors.
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#15
by
zubenelgenubi
on 15 Dec, 2022 05:21
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Member:
I really, really, really hope that the root cause was not MMOD damage from a too-small-to-detect-by-radar debris particle born in the Russian ASAT test. 
What do we know about Soyuz MS coolant leaks?
I had the same thought. "What goes around comes around" (especially in orbit).
We know that Soyuz uses water/glycol for the internal ECLSS (see above), and probably uses silicone oil for the external loop.
We'd better hope that it's not silicone oil leaking, because it has a nasty tendancy to react with atomic oxygen in LEO to form silica, forming permanent solid deposits which can foul external optics and sensors.
I would be very interested in any high-resolution imagery that the crew can get of the Soyuz radiator.
I also wonder if there will be a need for an EVA to investigate. 🔎 🤔 If so, I hope long, sharp knives are not required, as on the previous Soyuz inspection EVA a few years ago!
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#16
by
Steven Pietrobon
on 15 Dec, 2022 05:36
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Good video of the leak. Unfortunately, we don't get a direct view.
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#17
by
Steven Pietrobon
on 15 Dec, 2022 05:41
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Longer video of the leak. Its mentioned that the leak was associated with a drop in pressure in the Soyuz cooling system.
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#18
by
russianhalo117
on 15 Dec, 2022 06:33
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Cross-post:
https://forum.nasaspaceflight.com/index.php?topic=57741.msg2441074#msg2441074
Does a coolant leak like this one potentially compromise the departure and EDL ability of the Soyuz MS-22 spacecraft?
[zubenelgenubi: Posts split/merged to incident updates and discussion thread.]
No, because only one of the two redundant SOTR loops and coolant manifolds was lost. The other loop was operating isolated before the event and is functioning normally albeit compensating for the lost SOTR loop. The loops operate separately but can tied together in certain cases. There are two redundant loops for both the internal and external loops of SOTR system. The high beta angle is pushing Soyuz MS-22's SOTR system harder than other times though it had to be designed for these conditions. This I seem to recall not the first SOTR loop failure in the history of Soyuz, Progress and Soyuz derived station Service module components.
RSW subscription writeup:
http://russianspaceweb.com/protected/iss-vkd56.html#1214
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#19
by
AJW
on 15 Dec, 2022 06:43
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I believe that the market price Russia set for ferrying crew members from other countries up and down from the ISS was $86 million per seat. I suspect that at that rate SpaceX could have a Crew Dragon on the pad pretty quickly and turn a tidy profit.