20 ms·

NASA confirms space station cracking a "highest" risk and consequence problem

88 points by addaon 2y ago

addaon 2y ago
The joys of HN is finding experts in just about anything, so... Assuming that NASA is correct about this leak being associated with an interior or exterior weld, what can we learn from the rate of growth of the leak? I assume (with no domain knowledge, seeking enlightenment!) that a leak like this is big enough to reflect a fracture in the weld, and not merely air sneaking past a tiny flaw; and I assume its growth means that the fracture itself is growing, under the combination of load (atmospheric pressure on one side) and cycling (thermal, etc). Is a fracture like this likely to continue to grow in a linear-ish domain, or is there a point where propagation goes non-linear assuming the loads stay constant-ish? Is this even a sane question to ask?
- bt1a 2y ago
  Non-expert, pure speculator here: I cannot help but think of the Titan submersible and its minor flaw in the hull that slowly became more and more of an issue with each dive and pressurization cycle. I wonder if the 'untenable' leak rate that isn't agreed upon is the rate at which an accelerated and catastrophic runaway event occurs?
  - themaninthedark 2y ago
    There was no "minor flaw" in the Titan submersible. It was a very bad design[1], using substandard material[2] in new and untested ways[3] with poor assembly practices[4]. It was fatally flawed from the start. 1 - Asked about the carbon composite used in Titan’s experimental design, Cameron said, “It’s completely inappropriate for a vessel that sees external pressure.” He went on to say that carbon fiber is very helpful when used for applications subject to internal pressure, like scuba tanks. But, he said, “for something that’s seeing external pressure, all of the advantages of composite material go away and all the disadvantages come into play.” 2 - Another possible "shortcut": https://www.latestly.com/world/titan-submersibles-hull-was-apparently-made-of-expired-carbon-fiber-says-report-5224751.html https://www.latestly.com/world/titan-submersibles-hull-was-a... "Expired" bare carbon fiber might be ok; expired prepreg is likely not ok. And I still can't get my head around the apparent mixing of prepreg and wet winding resins in the same laminates. That article says Boeing has no record of ever selling oceangate composite material. So either he got it for free (Dumpster diving?) or it came from someone else. Maybe some guy in a parking lot: My boss told me to deliver this stuff to Boeing but they wouldn't take it because its expired, I'll sell it to you cheap. 3 - "Thickness, he says, was estimated using micromechanics, and then verified with finite element analysis (FEA).”. >Wonderful. That sort of maybe can work for tension stresses, but can be highly unreliable for compression loading 4 - https://www.youtube.com/watch?v=4PUTbK5AqY8 https://www.youtube.com/watch?v=4PUTbK5AqY8 : >For such a critical joint I see some questionable prep work >in the video. >-Bare hands touching the bond surface. >-Solvent wiping used instead of caustic degreasers. >-Poor wiping technique >-no surface profile/grit blast immediately prior to fixing. All sources are from commenters on: https://www.eng-tips.com/viewthread.cfm?qid=508005 https://www.eng-tips.com/viewthread.cfm?qid=508005
  - dotnet00 2y ago
    It's important to remember that the pressures involved are very different. The ISS pressure vessels only have to hold 1atm in, and not several atmospheres out.
    - bebop 2y ago
      To reinforce this point, it is around 375 atmospheres at the titanic. The deep sea is a crazy place.
    - jcranmer 2y ago
      Equally important is that the ISS is under tensile load (the cylinder is trying to explode), while a submersible is under compressive load (the cylinder is trying to implode).
      - rbanffy 2y ago
        It's just 1 atm. You can't even say it's trying seriously.
- jandrese 2y ago
  Obviously it can't be linear forever, if you assume the crack is along a circumference then eventually there will only be a tiny piece of metal still intact between the two halves, and one would expect it to fail far before then. These kinds of failures tend to be linear until they are not, and the failure mode is catastrophic. If I were in charge I would have already shut off that module on the risk/benefit analysis of catastrophic loss of the station vs. not being able to evacuate as quickly in a less catastrophic emergency. Maybe they are worried they won't be able to get the hatch open again if they can't equalize the pressure again? For historical reference, consider Aloha Airlines Flight 243[1]. https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243 https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243
  - DSMan195276 2y ago
    > Maybe they are worried they won't be able to get the hatch open again if they can't equalize the pressure again? Well note that they currently keep the hatch to the docking port closed unless they're using it, so that presumably mitigates some of the risk (assuming the leak is confined to that location). Not using the whole Zvezda module itself would be more or less impossible from my understanding. If they decided to stop using that dock port at all then I think that complicates planning and makes everything overall riskier, so while it wouldn't be a disaster to do there's still risk you have to weigh.
- debacle 2y ago
  Disclaimer: I don't know how space modules are welded or what forces act on a space module. Welds fail for multiple reasons - heating too fast, cooling too fast, material defects, human error, equipment issues, oxidation. The best human welder will still have some variance in their weld even if they lay a perfect bead. Once a weld begins to fail, under normal conditions (vibration, stress, etc), it will slowly get worse, but that can also mean deformation around the weld or even sometimes shearing right next to your weld. The article doesn't mention that the growth has been linear only that it is increasing. I expect that the leak is increasing over time in a non-linear fashion as force is applied to the weak area and metal continues to separate and/or shear. Still, 3.7 pounds of atmosphere a day is a very slow leak (relatively), a few bike tires a day.
  - rbanffy 2y ago
    My back of the napkin math tells me a .2 mm puncture would do this. This must be a very tiny crack. I'd just paint over all the welds and be happy until it unseals itself again.
- zardo 2y ago
  > Is a fracture like this likely to continue to grow in a linear-ish domain, or is there a point where propagation goes non-linear assuming the loads stay constant-ish? Is this even a sane question to ask? It depends on so much that we don't know from the article.
- hedora 2y ago
  From the article, it started leaking years ago, and almost doubled between Feb and Apr of this year, so it is definitely not growing linearly.
TomMasz 2y ago
It's hard to imagine US/Russian relations improving in the coming years. It might be easier and safer to retire the ISS sooner rather than later.
- neom 2y ago
  As a fun juxtaposition to your comment, here is a playlist of videos of them building it: https://www.youtube.com/playlist?list=PLYu7z3I8tdEnjgkBIBgxaJfZl2LdQN-rP https://www.youtube.com/playlist?list=PLYu7z3I8tdEnjgkBIBgxa...
- aaronblohowiak 2y ago
  it is planned for decommission. in the interim, they are isolating the impacted module and not planning repair (at least, that's what I got from the article!)
- rbanffy 2y ago
  You'll also need to have their agreement before you deorbit the Russian part. There is no way around that marriage (and it'd be better to make it work - space operations shouldn't be run by politicians anyway).
aaroninsf 2y ago
When I read this I understood _cracking_ in its sense of software piracy aka "hacking." A mental subprocesses spawned to predict whether the cracking was _of_ the systems on the station—possibly inspired by that movie trailer I saw for the thriller about a new cold war in space after a nuclear war—or _from_ the space station, by bored occupants, either of their own systems or of some system they interact with on the ground. A bit deflated by the reality, tbh.
accrual 2y ago
I wonder what kind of hardware debugging could be used to find the source of the leak. Could they spacewalk to the exterior of the tunnel and then emit some kind of detectible but inert gas from the interior to see where it appears outside? I suppose even if you found the leak there would still be some challenges in sealing it, especially if it's a growing leak like the data suggests. Would be a good experience for future space station maintenance though.
- cabirum 2y ago
  "tunnel that connects a larger module to a docking port" - reads like stress-induced metal fatigue, where it leaks a bit from every seam. It may not be a nice round hole somewhere.
  - rbanffy 2y ago
    And being a docking module, I'd guess it'd be near the docking port structure (although all Russian modules are connected via docking ports, rather than berthing ones).
  - potato3732842 2y ago
    Or just not an ideal design and the welded ring at the end is where it comes to a head because that's where the part connects to the next one. All aluminum stuff is gonna suffer fatigue problems eventually.
- bobmcnamara 2y ago
  For cars I've used a smoke generator (cigarette) and waved it around until the smoke is sucked into the vacuum leak. I'm sure NASA has something nicer.
  - deleted 2y ago
    [deleted]
  - jandrese 2y ago
    It is currently a very slow leak. That said a cloud of smoke shouldn't dissipate much at all in zero g so it might work.
mmooss 2y ago
> Once the station reaches the end of its life, NASA intends to transition its activities in low-Earth orbit onto private space stations, and it has funded initial development work by Axiom Space, Northrop Grumman, Blue Origin, and Voyager Space. One publication I read made a couple of relevant points: NASA should be careful about privatization and subcontracting, as it replaces NASA top-notch engineers with contract managers and oversight. Most engineers aren't interested in that work, and the skills don't stay sharp. Also, it said that Gateway, the space station planned to orbit the Moon, is considered the conceptual descendent of ISS. Much more here: https://nap.nationalacademies.org/cart/download.cgi?record_id=27519 https://nap.nationalacademies.org/cart/download.cgi?record_i... IMHO NASA should focus on the cutting edge, pushing the frontiers of space and technology. I'm glad they stopped bothering with orbital launch, which they've done for over 60 years - many countries and many private companies can do that now. I'm not sure where ISS falls - LEO is obviously relatively common technology, but habitation in orbit? Space stations orbiting the Moon are the kind of thing where NASA should aim.
- bdangubic 2y ago
  Hard to focus on the cutting edge, pushing the frontiers of space and technology with an ever-dwindling budget…
  - pieix 2y ago
    Surely ~$25B/year is enough to push the frontiers of space exploration?
    - bdangubic 2y ago
      We spend $900bn on “defense” so not really ;)
      - bdjsiqoocwk 2y ago
        What a stupid comment. How much is spent on defense affects exactly nothing to the question of how much work can be done with 25bn
amy-petrik-214 2y ago
There are rumors out there in the spacefaring community, wallpapered pretty heavily and media/google censored, regarding the astronaut responsible: https://www.newsweek.com/russia-could-take-legal-action-against-nasa-astronaut-accused-drilling-hole-spacecraft-1655420 https://www.newsweek.com/russia-could-take-legal-action-agai... Basically the full workup describes her having a mental breakdown and just making life up there more and more miserable, saying "take me home or I'll escalate" followed by many cycles of not being taken home and escalating. It includes stealing/losing most tools and equipment and "losing them" to the vacuum of space, drilling holes in the space station, and let us diplomatically say... very poor hygiene related to human waste. The astronaut involved basically quit doing any work. Supposedly this ruined the station and basically assured that it be taken offline.
- AIorNot 2y ago
  Gossip of course rises to the top I was an ISS Flight Controller for 6 years and worked in NASA mission planning and the idea that a us astronaut was “losing it in orbit and intentionally drilled a whole” is pretty ridiculous It’s obvious that the “hole” was some kind of miss by QA on the Russian side on the ground and it’s in Russian media interest currently to spread any unfounded speculation out into the interwebs Both the Russian Cosmonauts and US Astronauts were eminently professional people hardworking and dependable people and the also ground crews across the world who work night and day operating the station such that no ISS Crewmember should ever deserve to get their names dragged in the mud over this https://www.snopes.com/fact-check/nasa-astronaut-sabotage-iss/ https://www.snopes.com/fact-check/nasa-astronaut-sabotage-is...
  - GenerocUsername 2y ago
    As a Westerner, the gov blaming things on Russia is like a school kid saying their dog ate their homework... Even if it's true, ts so cliche at this point I just don't believe it
    - OKRainbowKid 2y ago
      It's almost as cliche as the Russian gov blaming the west for all their troubles.

88 points by addaon 2y ago

The joys of HN is finding experts in just about anything, so... Assuming that NASA is correct about this leak being associated with an interior or exterior weld, what can we learn from the rate of growth of the leak? I assume (with no domain knowledge, seeking enlightenment!) that a leak like this is big enough to reflect a fracture in the weld, and not merely air sneaking past a tiny flaw; and I assume its growth means that the fracture itself is growing, under the combination of load (atmospheric pressure on one side) and cycling (thermal, etc). Is a fracture like this likely to continue to grow in a linear-ish domain, or is there a point where propagation goes non-linear assuming the loads stay constant-ish? Is this even a sane question to ask?

bt1a 2y ago
Non-expert, pure speculator here: I cannot help but think of the Titan submersible and its minor flaw in the hull that slowly became more and more of an issue with each dive and pressurization cycle. I wonder if the 'untenable' leak rate that isn't agreed upon is the rate at which an accelerated and catastrophic runaway event occurs?
- themaninthedark 2y ago
  There was no "minor flaw" in the Titan submersible. It was a very bad design[1], using substandard material[2] in new and untested ways[3] with poor assembly practices[4]. It was fatally flawed from the start. 1 - Asked about the carbon composite used in Titan’s experimental design, Cameron said, “It’s completely inappropriate for a vessel that sees external pressure.” He went on to say that carbon fiber is very helpful when used for applications subject to internal pressure, like scuba tanks. But, he said, “for something that’s seeing external pressure, all of the advantages of composite material go away and all the disadvantages come into play.” 2 - Another possible "shortcut": https://www.latestly.com/world/titan-submersibles-hull-was-apparently-made-of-expired-carbon-fiber-says-report-5224751.html https://www.latestly.com/world/titan-submersibles-hull-was-a... "Expired" bare carbon fiber might be ok; expired prepreg is likely not ok. And I still can't get my head around the apparent mixing of prepreg and wet winding resins in the same laminates. That article says Boeing has no record of ever selling oceangate composite material. So either he got it for free (Dumpster diving?) or it came from someone else. Maybe some guy in a parking lot: My boss told me to deliver this stuff to Boeing but they wouldn't take it because its expired, I'll sell it to you cheap. 3 - "Thickness, he says, was estimated using micromechanics, and then verified with finite element analysis (FEA).”. >Wonderful. That sort of maybe can work for tension stresses, but can be highly unreliable for compression loading 4 - https://www.youtube.com/watch?v=4PUTbK5AqY8 https://www.youtube.com/watch?v=4PUTbK5AqY8 : >For such a critical joint I see some questionable prep work >in the video. >-Bare hands touching the bond surface. >-Solvent wiping used instead of caustic degreasers. >-Poor wiping technique >-no surface profile/grit blast immediately prior to fixing. All sources are from commenters on: https://www.eng-tips.com/viewthread.cfm?qid=508005 https://www.eng-tips.com/viewthread.cfm?qid=508005
- dotnet00 2y ago
  It's important to remember that the pressures involved are very different. The ISS pressure vessels only have to hold 1atm in, and not several atmospheres out.
  - bebop 2y ago
    To reinforce this point, it is around 375 atmospheres at the titanic. The deep sea is a crazy place.
  - jcranmer 2y ago
    Equally important is that the ISS is under tensile load (the cylinder is trying to explode), while a submersible is under compressive load (the cylinder is trying to implode).
    - rbanffy 2y ago
      It's just 1 atm. You can't even say it's trying seriously.
jandrese 2y ago
Obviously it can't be linear forever, if you assume the crack is along a circumference then eventually there will only be a tiny piece of metal still intact between the two halves, and one would expect it to fail far before then. These kinds of failures tend to be linear until they are not, and the failure mode is catastrophic. If I were in charge I would have already shut off that module on the risk/benefit analysis of catastrophic loss of the station vs. not being able to evacuate as quickly in a less catastrophic emergency. Maybe they are worried they won't be able to get the hatch open again if they can't equalize the pressure again? For historical reference, consider Aloha Airlines Flight 243[1]. https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243 https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243
- DSMan195276 2y ago
  > Maybe they are worried they won't be able to get the hatch open again if they can't equalize the pressure again? Well note that they currently keep the hatch to the docking port closed unless they're using it, so that presumably mitigates some of the risk (assuming the leak is confined to that location). Not using the whole Zvezda module itself would be more or less impossible from my understanding. If they decided to stop using that dock port at all then I think that complicates planning and makes everything overall riskier, so while it wouldn't be a disaster to do there's still risk you have to weigh.
debacle 2y ago
Disclaimer: I don't know how space modules are welded or what forces act on a space module. Welds fail for multiple reasons - heating too fast, cooling too fast, material defects, human error, equipment issues, oxidation. The best human welder will still have some variance in their weld even if they lay a perfect bead. Once a weld begins to fail, under normal conditions (vibration, stress, etc), it will slowly get worse, but that can also mean deformation around the weld or even sometimes shearing right next to your weld. The article doesn't mention that the growth has been linear only that it is increasing. I expect that the leak is increasing over time in a non-linear fashion as force is applied to the weak area and metal continues to separate and/or shear. Still, 3.7 pounds of atmosphere a day is a very slow leak (relatively), a few bike tires a day.
- rbanffy 2y ago
  My back of the napkin math tells me a .2 mm puncture would do this. This must be a very tiny crack. I'd just paint over all the welds and be happy until it unseals itself again.
zardo 2y ago
> Is a fracture like this likely to continue to grow in a linear-ish domain, or is there a point where propagation goes non-linear assuming the loads stay constant-ish? Is this even a sane question to ask? It depends on so much that we don't know from the article.
hedora 2y ago
From the article, it started leaking years ago, and almost doubled between Feb and Apr of this year, so it is definitely not growing linearly.

TomMasz 2y ago

It's hard to imagine US/Russian relations improving in the coming years. It might be easier and safer to retire the ISS sooner rather than later.

neom 2y ago
As a fun juxtaposition to your comment, here is a playlist of videos of them building it: https://www.youtube.com/playlist?list=PLYu7z3I8tdEnjgkBIBgxaJfZl2LdQN-rP https://www.youtube.com/playlist?list=PLYu7z3I8tdEnjgkBIBgxa...
aaronblohowiak 2y ago
it is planned for decommission. in the interim, they are isolating the impacted module and not planning repair (at least, that's what I got from the article!)
rbanffy 2y ago
You'll also need to have their agreement before you deorbit the Russian part. There is no way around that marriage (and it'd be better to make it work - space operations shouldn't be run by politicians anyway).

aaroninsf 2y ago

When I read this I understood _cracking_ in its sense of software piracy aka "hacking." A mental subprocesses spawned to predict whether the cracking was _of_ the systems on the station—possibly inspired by that movie trailer I saw for the thriller about a new cold war in space after a nuclear war—or _from_ the space station, by bored occupants, either of their own systems or of some system they interact with on the ground. A bit deflated by the reality, tbh.

accrual 2y ago

I wonder what kind of hardware debugging could be used to find the source of the leak. Could they spacewalk to the exterior of the tunnel and then emit some kind of detectible but inert gas from the interior to see where it appears outside? I suppose even if you found the leak there would still be some challenges in sealing it, especially if it's a growing leak like the data suggests. Would be a good experience for future space station maintenance though.

cabirum 2y ago
"tunnel that connects a larger module to a docking port" - reads like stress-induced metal fatigue, where it leaks a bit from every seam. It may not be a nice round hole somewhere.
- rbanffy 2y ago
  And being a docking module, I'd guess it'd be near the docking port structure (although all Russian modules are connected via docking ports, rather than berthing ones).
- potato3732842 2y ago
  Or just not an ideal design and the welded ring at the end is where it comes to a head because that's where the part connects to the next one. All aluminum stuff is gonna suffer fatigue problems eventually.
bobmcnamara 2y ago
For cars I've used a smoke generator (cigarette) and waved it around until the smoke is sucked into the vacuum leak. I'm sure NASA has something nicer.
- deleted 2y ago
  [deleted]
- jandrese 2y ago
  It is currently a very slow leak. That said a cloud of smoke shouldn't dissipate much at all in zero g so it might work.

mmooss 2y ago

> Once the station reaches the end of its life, NASA intends to transition its activities in low-Earth orbit onto private space stations, and it has funded initial development work by Axiom Space, Northrop Grumman, Blue Origin, and Voyager Space. One publication I read made a couple of relevant points: NASA should be careful about privatization and subcontracting, as it replaces NASA top-notch engineers with contract managers and oversight. Most engineers aren't interested in that work, and the skills don't stay sharp. Also, it said that Gateway, the space station planned to orbit the Moon, is considered the conceptual descendent of ISS. Much more here: https://nap.nationalacademies.org/cart/download.cgi?record_id=27519 https://nap.nationalacademies.org/cart/download.cgi?record_i... IMHO NASA should focus on the cutting edge, pushing the frontiers of space and technology. I'm glad they stopped bothering with orbital launch, which they've done for over 60 years - many countries and many private companies can do that now. I'm not sure where ISS falls - LEO is obviously relatively common technology, but habitation in orbit? Space stations orbiting the Moon are the kind of thing where NASA should aim.

bdangubic 2y ago
Hard to focus on the cutting edge, pushing the frontiers of space and technology with an ever-dwindling budget…
- pieix 2y ago
  Surely ~$25B/year is enough to push the frontiers of space exploration?
  - bdangubic 2y ago
    We spend $900bn on “defense” so not really ;)
    - bdjsiqoocwk 2y ago
      What a stupid comment. How much is spent on defense affects exactly nothing to the question of how much work can be done with 25bn

amy-petrik-214 2y ago

There are rumors out there in the spacefaring community, wallpapered pretty heavily and media/google censored, regarding the astronaut responsible: https://www.newsweek.com/russia-could-take-legal-action-against-nasa-astronaut-accused-drilling-hole-spacecraft-1655420 https://www.newsweek.com/russia-could-take-legal-action-agai... Basically the full workup describes her having a mental breakdown and just making life up there more and more miserable, saying "take me home or I'll escalate" followed by many cycles of not being taken home and escalating. It includes stealing/losing most tools and equipment and "losing them" to the vacuum of space, drilling holes in the space station, and let us diplomatically say... very poor hygiene related to human waste. The astronaut involved basically quit doing any work. Supposedly this ruined the station and basically assured that it be taken offline.

AIorNot 2y ago
Gossip of course rises to the top I was an ISS Flight Controller for 6 years and worked in NASA mission planning and the idea that a us astronaut was “losing it in orbit and intentionally drilled a whole” is pretty ridiculous It’s obvious that the “hole” was some kind of miss by QA on the Russian side on the ground and it’s in Russian media interest currently to spread any unfounded speculation out into the interwebs Both the Russian Cosmonauts and US Astronauts were eminently professional people hardworking and dependable people and the also ground crews across the world who work night and day operating the station such that no ISS Crewmember should ever deserve to get their names dragged in the mud over this https://www.snopes.com/fact-check/nasa-astronaut-sabotage-iss/ https://www.snopes.com/fact-check/nasa-astronaut-sabotage-is...
- GenerocUsername 2y ago
  As a Westerner, the gov blaming things on Russia is like a school kid saying their dog ate their homework... Even if it's true, ts so cliche at this point I just don't believe it
  - OKRainbowKid 2y ago
    It's almost as cliche as the Russian gov blaming the west for all their troubles.