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One hull crack located in ISS, another one suspected

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Re: One hull crack located in ISS, another one suspected

#31

Post by NickNameNick »

artiscode wrote: post #12

I wonder if radiation will become an issue at some point. It is being irradiated all the time, doesn’t it also start to leak inside? Can that be an issue in the future for inhabitable objects in space?

That depends on what you mean by radiation, and 'leak inside'

On the ground, most radiation 'leaks' are mostly chemical contamination problems.

In space the volume of free material, and the pressure gradient should prevent anything outside coming in. Except perhaps on the exposed surfaces of the airlocks/docking adapters.

Come types of particle radiation might cause transmutation/activiation of the hull material - that could be a concern. I doubt it's major issue.

Re: One hull crack located in ISS, another one suspected

#32

Post by spike021 »

Not a big space person, but this makes me wonder: why have we not planned for a new ISS? We must have better tech nowadays from all the working countries/groups currently involved, plus SpaceX and other space companies' backing that would not have existed as it does now back when this ISS was first designed/created.

Re: One hull crack located in ISS, another one suspected

#33

Post by tomcam »

akiselev wrote: post #10
ChuckMcM wrote: post #2

Materials aging in space is a pretty deep subject. That it is the Russian Zvevda module that is leaking/cracking is likely related to the fact that it is also the oldest module in the ISS. The ISS is/was scheduled to be retired in 2024 (aka 3 years from now) but there are calls to keep it going. My fantasy would be to have SpaceX move it into the Lunar L1 Lagrange point which would keep it in use but it would have to…

> That it is the Russian Zvevda module that is leaking/cracking is likely related to the fact that it is also the oldest module in the ISS. Definitely sounds like it. They can't identify the leak on the inside so it doesn't sound like a micrometeoroid impact and they suspect a second leak that is so small they need a microscope to verify: > "So far, we have found one place and suspect another, where as some kind of l…

Hmm... my first encounter with "IANAMS" in the wild. Assume it means "I am not a materials scientist"? I like it.

Re: One hull crack located in ISS, another one suspected

#34

Post by spiritplumber »

spike021 wrote: post #32

Not a big space person, but this makes me wonder: why have we not planned for a new ISS? We must have better tech nowadays from all the working countries/groups currently involved, plus SpaceX and other space companies' backing that would not have existed as it does now back when this ISS was first designed/created.

The ISS mostly happened because it was a way to keep ex-Soviet aerospace scientists and engineers doing aerospace things rather than, say, go build ICBMs for third world countries.

Same as Arecibo happened because the USAF wanted a big radar and the Hubble happened because (I forgot which spy agency it was) had a spare satellite.

Sad when you think about it...

Re: One hull crack located in ISS, another one suspected

#35

Post by maxerickson »

sailingparrot wrote: post #30
lmilcin wrote: post #15

Earlier quoted context omitted.

Hull is definitely not decomposing or degrading. If left in peace at sufficiently high altitude it would look the same in a million years. My bet is the issue is most likely stresses due to vibrations under pressure and pressure changes. It is complex but also well known problem. As the astro/kosmonauts move about the station, resupply dock, pressure changes, etc. some parts are being subject to constantly changing s…

> My bet is the issue is most likely stresses due to vibrations under pressure and pressure changes. So you are saying it's degrading?

These discussions about materials are often difficult, because there are meaningfully different processes that are lumped together in everyday language.

Mechanical stresses leading to failure at a particular point are certainly a form of degradation, but I believe they mean degradation in the sense where the entire body of the material is undergoing some change (like a plastic bottle fogging or such).

I think seeking clear descriptions is fine, treating it as a "gotcha" game is tedious and unnecessary.

Re: One hull crack located in ISS, another one suspected

#36

Post by sudosysgen »

TeMPOraL wrote: post #26
kevin_thibedeau wrote: post #14

Earlier quoted context omitted.

Save a seat for the Flex Seal guy.

You're joking but this reminds me of a hard sci-fi novel I read recently, Saturn Run[0]. One of the minor worldbuilding trivia there is that adhesives seem to be way overused to fix and modify things in space. (The book also features the coolest design for a radiator I've ever seen anywhere.) -- [0] - https://www.goodreads.com/book/show/24611668-saturn-run

Out of the curiosity, what is the radiator design?

Re: One hull crack located in ISS, another one suspected

#37

Post by HPsquared »

bartread wrote: post #13
akiselev wrote: post #10

Earlier quoted context omitted.

> That it is the Russian Zvevda module that is leaking/cracking is likely related to the fact that it is also the oldest module in the ISS. Definitely sounds like it. They can't identify the leak on the inside so it doesn't sound like a micrometeoroid impact and they suspect a second leak that is so small they need a microscope to verify: > "So far, we have found one place and suspect another, where as some kind of l…

Is it possible it could also be from constant heating and cooling cycles as it orbits?

Those are the cause of the stress cycles. Components don't expand/contact uniformly, resulting in deformation and therefore stress. This process goes through cycles, causing stress cycles which eventually cause the growth of cracks (fatigue).

Re: One hull crack located in ISS, another one suspected

#38

Post by HPsquared »

sailingparrot wrote: post #30
lmilcin wrote: post #15

Earlier quoted context omitted.

Hull is definitely not decomposing or degrading. If left in peace at sufficiently high altitude it would look the same in a million years. My bet is the issue is most likely stresses due to vibrations under pressure and pressure changes. It is complex but also well known problem. As the astro/kosmonauts move about the station, resupply dock, pressure changes, etc. some parts are being subject to constantly changing s…

> My bet is the issue is most likely stresses due to vibrations under pressure and pressure changes. So you are saying it's degrading?

Degradation of the structural integrity, I'd say.

Re: One hull crack located in ISS, another one suspected

#39

Post by pengaru »

ben_w wrote: post #19
pengaru wrote: post #9

Earlier quoted context omitted.

Especially for "cold butter" metals like aluminum and copper.

I’ve never heard that phrase used in this content before. How does “cold butter” apply to these metals?

I don't recall which of the many print books I read in my gearhead/TIG-welding days had used the term, but the lack of a distinct fatigue/endurance limit [0] for these metals was put into practical terms with something along the lines of "like slightly bending a cold stick of butter".

It's why aluminum airplanes are supposed to get inspected for cracks regularly, and why aluminum bicycle frames must be so uncomfortably rigid. If there's cyclic stress occurring, it's a question of when, not if they will crack.

If I had to guess it's from Carroll Smith's 80s-era Engineer to Win, it sounds like something he'd write.

[0] https://en.wikipedia.org/wiki/File:S-N_curves.PNG

Re: One hull crack located in ISS, another one suspected

#40

Post by HPsquared »

spiritplumber wrote: post #34
spike021 wrote: post #32

Not a big space person, but this makes me wonder: why have we not planned for a new ISS? We must have better tech nowadays from all the working countries/groups currently involved, plus SpaceX and other space companies' backing that would not have existed as it does now back when this ISS was first designed/created.

The ISS mostly happened because it was a way to keep ex-Soviet aerospace scientists and engineers doing aerospace things rather than, say, go build ICBMs for third world countries. Same as Arecibo happened because the USAF wanted a big radar and the Hubble happened because (I forgot which spy agency it was) had a spare satellite. Sad when you think about it...

Satellites in general happened as a result of an arms race.
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