News Small leak aboard ISS

[IronRain]

Brought to you by tl8 over at Discord:

https://www.reddit.com/r/space/comments/9bi49u/the_iss_is_currently_experiencing_a_slow/

Update: the leak would be in the orbital module of the Soyuz docked to MRM-1 (Rassvet).
Update 2: they found a 2mm hole near the hatch of the Soyuz.
Update 3: the hole is covered (possibly by tape, I'm not sure using Alexander Gerst's finger for now) and the pressure is now stable.
Update 4: Alexander said it looked like a drilled hole that might have been there for quite some time, I'm not sure about what I hear but the repair might be a little bit more complicated since covering it is not entirely stopping the leak. Some pieces of metal might have been twisted a bit.
Update 5: the hole has been covered by kapton tape, but there would still be a small leak.
Update 6: the depressurization rate has been divided by 6, if they don't do anything about it they'll have 18 days before the station is empty of air which gives them a lot of time to find a solution.

 

[IronRain]

Updates:

Update 7: astronauts are currently searching for the external holes from the Cupola using zoom lenses and binoculars. The inner hole is going to be repared using a special kit (I'm unsure about what it is exactly, sorry)
Update 8: the current depressurization rate is of 0,1mmHg/min which is not a problem, it's going to be fixed very soon I believe. The crew is not in danger and this isn't a big emergency.
Update 9: official NASA blog post about the event
Update 10: Pictures of the hole have been sent to the ground and are being studied.

 

[Urwumpe]

That sounds like it can get fixed, but two mm hole is a lot.

 

[Artlav]

I wonder if the leak makes any sound. Normally you'd expect there to be a whistle or something, but that is generated on the far side of the hole AFAIK, so there is no way for it to propagate back in.

 

[Urwumpe]

I wonder if the leak makes any sound. Normally you'd expect there to be a whistle or something, but that is generated on the far side of the hole AFAIK, so there is no way for it to propagate back in.

The flow towards the hole should still be subsonic, so something should be audible, but it might sound differently.

 

[Capt_hensley]

Just shoot a wet sealant blind fastener in the pressure hull and call it a day. It would take a -8 dia blind fastener. Easy fix, no hoopla!

 

[Urwumpe]

Just shoot a wet sealant blind fastener in the pressure hull and call it a day. It would take a -8 dia blind fastener. Easy fix, no hoopla!

1/8" might be a bit large for that hole... not sure if drilling into the pressure hull is a smart idea.

 

[jedidia]

Just shoot a wet sealant blind fastener in the pressure hull and call it a day.

Not sure they've got one of those :lol:

 

[emin2004]

it's a game of survival aboard the ISS

 

[kuddel]

Updates:

Update 11: The livestream is not giving any new information for now, so I'm stopping the live coverage for now. I'll try to keep you updated if something happens. If I got anything wrong during the updates I'm sorry but it's really hard to understand exactly what's being said on the livestream!
Update 12: Patches are currently being installed over the hole.
Update 13: I haven't been following the livestream for quite some time but from what I heard, astronauts and ground team are still searching for the best way to entirely fix the issue since some air is still leaking very slowly (approx 0.6mmHg/hr from what I read).
Update 14: There has been a small disagreement between Houston and Moscow about the fix of the situation, NASA Astronaut Drew Feustel asked for more time of thinking but Russian ground team wants to take care of the issue faster using sealant.
Update 15: Russian ground team asked to wait 1 hour before doing anything with the sealant.
Update 16: Sealant has been applied, the leak appears to have stopped. Cosmonaut is talking about bubbles but I'm not sure.
Update 17: Russian ground team asked to wait for tomorrow morning before taking any new decision. Tomorrow, they'll perform a leak check and will take actions according to that.
Update 18: Pressure is still stable after almost 20 minutes.

---------- Post added 31-08-18 at 08:43 ---------- Previous post was 30-08-18 at 21:22 ----------

...Scott Manleys comment on this:

---------- Post added at 17:37 ---------- Previous post was at 08:43 ----------

NASASpaceFlight.com has some more on this (with photo!)

 

[Urwumpe]

NASASpaceFlight.com has some more on this (with photo!)

Doesn't look like a manufacturing error at all like Ulrich Walter was prefering as hypothesis.

 

[kuddel]

From the photo of the hole I would have guessed it's a drilled hole. Most possibly drilled way back when it was still on the ground.
But then something on the outer shell has leaked, so that this was the "port" the air got sucked into the section between inner and outer hull. That leak however could be at almost any place, so sealing the inner shell might have been the only practical way to fix it anyway...

I totally agree with what ellindsay posted here:

Circular scoring inside the hole, tooling marks on the surface nearby that look like a drill bit skipping, and a scuff mark on the bulkhead nearby that looks like the drill chuck rubbing against it. That looks exactly like a hole made by a handheld power drill.

 

[Urwumpe]

From the photo of the hole I would have guessed it's a drilled hole. Most possibly drilled way back when it was still on the ground.
But then something on the outer shell has leaked, so that this was the "port" the air got sucked into the section between inner and outer hull. That leak however could be at almost any place, so sealing the inner shell might have been the only practical way to fix it anyway...

I totally agree with what ellindsay posted here:

Not sure there. And after all - why are they making leak checks before launch, if they are not detecting such leaks? Why wasn't the leak an issue before docking?


And AFAIR, there is no inner and outer shell on a Soyuz OM. it just has a thin metal pressure vessel and some thermal blankets.

 

[mahdavi3d]

 

[Astrozeke]

The leak was relatively slow, but we do have ultrasonic leak detector kits onboard that act as a kind of ultrasound. Once the patch was in place, Alex used this kit to take readings to see if the leak was still occurring. Pressure has been holding steady since the patch was applied, and ETHOS has has their collective eyes on the dp/dt plot.

 

[boogabooga]

From the photo of the hole I would have guessed it's a drilled hole. Most possibly drilled way back when it was still on the ground.
But then something on the outer shell has leaked, so that this was the "port" the air got sucked into the section between inner and outer hull. That leak however could be at almost any place, so sealing the inner shell might have been the only practical way to fix it anyway...

I totally agree with what ellindsay posted here:

Guys with the conspiracy theories, come on already. So how would that look different from a micrometeor impact hole? Why would anyone sabotage their own mission with something that is easily fixed anyway?

 

[Quick_Nick]

Guys with the conspiracy theories, come on already. So how would that look different from a micrometeor impact hole? Why would anyone sabotage their own mission with something that is easily fixed anyway?

It's not about sabotage, just the possibility that this inner hole already existed and happened to connect to a new outer hole (or stopped being sealed).
The Soyuz has been docked for just under three months, so it wouldn't be as surprising if it had an unnoticed hole compared to the older ISS modules.

I just learned that the close-up image that Chris Hadfield posted on Twitter is not actually the same hole. It's a debris hole from the SolarMax satellite.
The hole in the Soyuz looks distinctly less impact-like and more drill-like for the reasons mentioned previously.

As far as I am aware, NASA has yet to call it a micrometeoroid impact and experts suggest it probably was not one. It remains to be seen whether the Russians are quick to label it and patch due to: expertise, a desire to not dwell on minor things, or a desire to hide a workmanship issue.

 

[kuddel]

Not sure there. And after all - why are they making leak checks before launch, if they are not detecting such leaks? Why wasn't the leak an issue before docking?

I don't know either. I should have made this more clear: This is just me guessing, speculating if you will, but hopefully based on some "evidence".

And AFAIR, there is no inner and outer shell on a Soyuz OM. it just has a thin metal pressure vessel and some thermal blankets.

Hm if that's the case, that hole might have had a rivet in it. On the ground that rivet had to be replaced (for whatever reason) explaining the other drill marks...
After the new rivet was placed, it would definitely have been tested. That was O.K. during test, but was "cut" by shearing forces later on.
But again: That's just me thinking of what might have happened to produce this picture...

I should maybe just be a bit more patient and wait for further facts to be released :thumbup:

 

[Urwumpe]

Hm if that's the case, that hole might have had a rivet in it. On the ground that rivet had to be replaced (for whatever reason) explaining the other drill marks...

Well, the Soyuz book is pretty exact there about how the OM is produced. Its welded together from multiple segments.



But I am wrong as well there: One of the later improvements on the Soyuz TMA-M spacecraft was the addition of MMOD shields to the OM on request by NASA. So, while no full double-hull arrangement and just one pressure hull, there are whipple shields all around the OM since 2010.



This report talks about the expected costs and effects of the Soyuz shielding, also it shows a picture of a perforation on a MPLM shield on the outside face.



https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060026214.pdf

I can see why NASA is reluctant to call this a MMOD damage, the much bigger area of spalled paint is missing here. Also, MMOD impacts usually have a much smaller inside diameter than outside diameter. The example tapers from 2.5 mm outside to 1.4 mm diameter inside.

Also here is a small picture of the actual shielding installed:

http://www.russianspaceweb.com/soyuz-ms.html

 

[C3PO]