Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Astronauts told to return to ISS after sheltering over air leak repairs

bbc.com

Post reply on HN
Print view View original

221–230 of 283 posts

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#221

Post by saltcured »

Kye wrote: post #205
rconti wrote: post #124

> After multiple inspections and sealant applications, Nasa reported in January that pressure readings suggested a stable configuration had been reached - though there remained uncertainty about whether the leak had truly been sealed or whether air was simply escaping elsewhere. I'm clearly not understanding what they're trying to say here. If _one_ leak was sealed, but the air was "escaping elsewhere", it would stil…

It's an almost 30 year old nearly 500 ton structure subjected to radiation, bombardment by starstuff and debris, the stresses of docking and undocking, of boosts, and of constant heating and cooling as it passes in and out of the sun. Getting a clear picture of the comings and going of gasses is probably not easy.

Take away the mass figure, and it happens to all of us eventually ;-)

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#222

Post by sam1714 »

dmurray wrote: post #199
sam1714 wrote: post #164

Earlier quoted context omitted.

Candles are useful when oxygen has been consumed because of respiration or a fire. They're not useful in a leak. Conservation of mass: if a cubic meter of air escapes, that's 1.25 kg, and you need at least that much in candles. (You actually need 2 kg because the candle isn't solid oxygen) There's ultimately 1.2 t of atmosphere on the ISS. This will also result in a pure oxygen atmosphere, which is dangerous. You nee…

I think you're double counting; you need 1.25 kg of oxygen and nitrogen combined to replace 1 cubic metre of air. 1.2t of candles doesn't seem like an unreasonable amount of extra payload if they would really be valuable in an emergency. The ISS weighs 400 tons and a napkin estimate says it has had 1000 tons of resupply missions. The candles have a shelf life of 10+ years.

You need 1.25 kg of gas. Candles don't consist solely of oxygen, the ones the Russians use utilize lithium perchlorate (LiClO4). When they finish burning, you are left with a lithium chloride ash (LiCl), which will be 40% mass of what you started with.

It works out to be more efficient, at least in terms of mass, to send up large tanks of compressed gas instead.

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#223

Post by hagbard_c »

djmips wrote: post #190
ActorNightly wrote: post #162

Earlier quoted context omitted.

[flagged]

... and returning is mostly by gravity.

Yes, well, that and by aerobraking in the atmosphere where all that potential energy the capsule gained during launch has to be shed. There's plenty of reentry videos from Starship tests which show what happens to vehicle parts which are less protected by heat shields.

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#225

Post by ChoGGi »

Forgeties79 wrote: post #155
MSKJ wrote: post #127

Earlier quoted context omitted.

Duct Tape, the answer is always duct tape

Found the scrub who doesn’t know about gaff tape

I don't think you can be an astronaut on the ISS without being a handyman, and the handyman's secret weapon is duct tape.

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#226

Post by NetMageSCW »

numpad0 wrote: post #210
snickerbockers wrote: post #147

Earlier quoted context omitted.

Put a bit of spare sheet metal over the hole and let the pressure differential hold it down. For added safety affix a post-it not with DO NOT REMOVE written on it in all capital letters and underlined. They can even use those special zero-g ballpoint pens they spent eleventy-billion dollars inventing back during the johnson administration.

But they still haven't located the leak. My blob of glue idea solves that by automatically permeating into the cracks. wait, do they have to have matched CTE and k to the existing material... hmm

Do you know what causes superglue to harden? Do you think that will be found in a vacuum?

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#227

Post by whycome »

Kye wrote: post #205
rconti wrote: post #124

> After multiple inspections and sealant applications, Nasa reported in January that pressure readings suggested a stable configuration had been reached - though there remained uncertainty about whether the leak had truly been sealed or whether air was simply escaping elsewhere. I'm clearly not understanding what they're trying to say here. If _one_ leak was sealed, but the air was "escaping elsewhere", it would stil…

It's an almost 30 year old nearly 500 ton structure subjected to radiation, bombardment by starstuff and debris, the stresses of docking and undocking, of boosts, and of constant heating and cooling as it passes in and out of the sun. Getting a clear picture of the comings and going of gasses is probably not easy.

Are there things that happen on board that increase the pressure - eg fermentation whether it’s experiment or in humans?

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#228

Post by NetMageSCW »

pantalaimon wrote: post #44
tedivm wrote: post #18

Earlier quoted context omitted.

This is just not true. There have been leaks due to micrometers in just about every section of the ship at one point or another. A quick search pulls up examples of US modules having issues, especially around interfaces and seals. NASA had a whole investigation between 2018 and 2021 about the recurring issue.

Maybe we can use the goop from those self sealing bike tires to have self sealing space station modules

They were never stranded.

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#229

Post by dlgeek »

PunchyHamster wrote: post #193
GolfPopper wrote: post #170

Earlier quoted context omitted.

Is there any rocket-builder without a history of blowing things up?

Saturn 1 and 1B didn't have failure I think ? Tho that's just one model

Made by Chrysler. They had plenty of failures with the Juno I and Juno II launchers.

Re: Astronauts told to return to ISS after sheltering over air leak repairs

#230

Post by malfist »

Dylan16807 wrote: post #149
malfist wrote: post #80

Earlier quoted context omitted.

For every complex, difficult and hard problem, there is a simple, easy and wrong solution. Paint obviously is not the right tool for making seals air tight.

It is not obvious to me that there is no specialized type of paint that would be appropriate. Doing the whole module sounds like a lot of mass though.

The odds of the leak being on a surface that can be painted is low. Most likely it's in a gasket or seal that has degraded
Post reply on HN