
Slow leak detected aboard Space Station - sanqui
http://blogs.esa.int/alexander-gerst/2018/08/30/slow-leak-detected-aboard-space-station/
======
snsr
Apparently a 1.5mm puncture due to a meteor/debris strike in the Russian Soyuz
MS-09 module.

More information:

[http://blogs.esa.int/alexander-gerst/2018/08/30/slow-leak-
de...](http://blogs.esa.int/alexander-gerst/2018/08/30/slow-leak-detected-
aboard-space-station/)

[https://twitter.com/RussianSpaceWeb?ref_src=twsrc%5Egoogle%7...](https://twitter.com/RussianSpaceWeb?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor)

[http://www.russianspaceweb.com/soyuz-
ms-09.html#leak](http://www.russianspaceweb.com/soyuz-ms-09.html#leak)

~~~
kevindqc
How does it not happen more often?

~~~
antonvs
Micrometeoroid impacts happen fairly regularly, but they're usually not
energetic enough to make a hole. For example, there was a instance in 2012
where one hit a window: [http://www.spacesafetymagazine.com/space-
debris/kessler-synd...](http://www.spacesafetymagazine.com/space-
debris/kessler-syndrome/micrometeroid-hit-iss-cupola/)

But as that incident shows, such impacts are often relatively benign - in that
case, they didn't even need to replace the outer layer window.

The hull is reinforced with four or five layers of shielding - the above
article has a nice diagram: [https://i2.wp.com/www.spacesafetymagazine.com/wp-
content/upl...](https://i2.wp.com/www.spacesafetymagazine.com/wp-
content/uploads/2012/06/MMOD-typical-shields.jpg)

This means the usual consequence of a micrometeroid impact is pitting of the
outer layers that may not even be noticed.

For larger objects that present a serious danger, the US Space Surveillance
Network attempts to track them and predict "conjunctions" with a zone around
the ISS which extends 2km above and below it, and 25 km in each direction on
the orbital path. Anything that's expected to intersect with this zone is
analyzed and may result in the station being moved to get out of the way.
These are mostly due to space junk of human origin. In 2013, there were at
least ~70 of these "conjunction notifications", although this results in only
about one move of the station per year, on average.

There's a description of how these cases are handled at
[https://arstechnica.com/science/2013/07/how-nasa-steers-
the-...](https://arstechnica.com/science/2013/07/how-nasa-steers-the-
international-space-station-around-space-junk/) :

> "Any object with between a 1-in-10,000 and 1-in-100,000 chance of colliding
> with the station meets the "yellow" threshold. Flight rules say that the
> station must be moved out of the way in response to a yellow threshold
> object unless such a move results in a mission impact—"Like, if we do the
> burn, we're going to miss an opportunity to launch a Soyuz, for instance,"
> explains Parris. "Do we delay the Soyuz, or do we do the maneuver?" A "red"
> threshold is assigned to any collision with a likelihood of between 1 (in
> other words, absolutely certain) and 1-in-10,000. Flight rules are more
> strict for maneuvers in response to red threshold objects: the station is
> always moved for a red threshold object, regardless of mission impact,
> unless a maneuver represents more risk than not maneuvering (for example, if
> there's a piece of equipment that's damaged on the ISS and a maneuver would
> exacerbate that damage)."

This doesn't help in the case of meteor showers, where the Earth is travelling
through a zone full of small debris, typically caused by the trail of a comet.
In those cases, the station has to rely on its shielding, but the debris sizes
in those cases are almost all within the limits that the shielding can handle.

~~~
hssys
Very informative post, thanks!

------
swypych
"The rate of the leak was slowed this morning through the temporary
application of Kapton tape at the leak site."

In tape we trust!

I hope they show close ups!

~~~
pcrh
>Kapton tape

Is that duck tape for spaceships?

~~~
cjslep
Duct tape?

Or tape for ducks?

~~~
Afton
[https://mentalfloss.com/article/52151/it-duck-tape-or-
duct-t...](https://mentalfloss.com/article/52151/it-duck-tape-or-duct-tape)

------
asteli
At 1.5mm, a piece of tape would come closer than you'd think to being a
permanent fix...

The vacuum of space seems drastically hard to keep at bay, but consider that
you're only holding in enough gas to replicate sea-level air pressure
(nominally 14 PSI or so). A typical soda can is pressurized to between 30 and
50 PSI depending on temperature, beverage etc.

Supposedly the apollo command module had a pressure skin that was as thin as
0.012" (0.3mm) in places.

~~~
userbinator
I did a bit of searching and found that the ISS, along with Soyuz, are kept at
sea-level atmospheric pressure (14.7PSI). This is unlike pressurised aircraft,
which usually operate slightly below sea-level pressure at flying altitude.

[https://en.wikipedia.org/wiki/Cabin_pressurization#Spacecraf...](https://en.wikipedia.org/wiki/Cabin_pressurization#Spacecraft)

------
alkonaut
How do you find it, once you register that there IS a leak? Will there be a
draft towards the hole? Or do they use an outside IR camera?

~~~
tropo
It might whistle, perhaps ultrasonically.

It might produce a tiny little thrust.

~~~
jhpankow
Indeed they used an ultrasonic leak detector.

------
pbrumm
I don't think they could fit another video or unrelated image in that article.

Are people posting content here just to get the ads traffic?

~~~
_verandaguy
This is the official ESA website, they don't generate ad revenue AFAIK, or any
revenue from their site directly.

~~~
greglindahl
The original url was at independent.co.uk, one of the UK's national
newspapers.

------
sitkack
At 1.5mm dust could block that hole from the inside and _sufficiently large
(epoxy) bandaid_ could patch it from the outside.

Edit, from twitter link, "... has been sealed temporarily by tape ..."

~~~
cwkoss
Interesting, I was thinking you could use the pressure differential to flow
epoxy into the hole before sealing pressure to stop flow and heating to cure,
but makes sense that an epoxy bandaid would probably do just as well -
probably good enough to just slap that over the hole.

Will they apply to both inside and out? Will epoxy cure properly if totally
exposed to the cold low pressure of space?

~~~
AWildC182
Epoxy can cure in a vacuum, as demonstrated by common fabrication procedures
(sort of). The temperature isn't actually that big of a thing. Space is "cold"
because there's no heat but also nothing to conduct it away. It actually gets
quite hot if you're facing the sun as well. Long story short though, as long
as there's no gas passing through the hole, it should stay around the internal
temperature of the ISS or at least close enough to cure.

~~~
lpmay
Maybe even hotter than inside, since the epoxy reaction is exothermic as it
cures.

------
thibran
ISS Live Stream: [http://www.ustream.tv/channel/live-iss-
stream](http://www.ustream.tv/channel/live-iss-stream)

~~~
sometime
How did they locate the hole?

------
pcan77
Sounds like they needed an inanimate carbon rod!

~~~
whoopdedo
This is a Simpsons reference but it also sounds like a variation of the "the
Russians used a pencil" copypasta.

------
joering2
Has been fixed by now.

IF you have spare monitor going at your office/home, its fun to watch the ISS
up to second tracking locations [1].

Fun fact I learned lately about ISS: at 400km above Earth's surface, the
gravity is about 80% of a normal Earth gravity. The ISS is constantly falling
down but because of Earth rotation it is falling "at the edge" so to speak so
it never actually fell on the ground. Hope that make sense, I'm sure you read
better explanation on Wiki.

[1]
[http://www.esa.int/Our_Activities/Human_Spaceflight/Internat...](http://www.esa.int/Our_Activities/Human_Spaceflight/International_Space_Station/Where_is_the_International_Space_Station)

~~~
coldtea
> _Fun fact I learned lately about ISS: at 400km above Earth 's surface, the
> gravity is about 80% of a normal Earth gravity._

That doesn't seem to match the movies of ISS shown, where there seems to be no
(or very small) gravity. In 80% of normal earth gravity water wouldnt stay up
in the air for example, and cosmonauts wouldn't be floating around in the
station as we see in the videos...

~~~
JabavuAdams
This is why we should use the term "free-fall", instead of "zero-gravity".

There is no way known to remove gravity. At best, you can cause the room to
fall at the same rate as the things inside the room, causing the contents to
float around.

It's the same principle that allows specialized airplanes to create the
sensation of weightlessness, while very-much in almost Earth-surface gravity.

~~~
coldtea
> _There is no way known to remove gravity_

Well, you can go far away from large masses to effectively diminish e.g.
earth's gravity though, no?

> _It 's the same principle that allows specialized airplanes to create the
> sensation of weightlessness, while very-much in almost Earth-surface
> gravity._

Yes, but I was confused because space offers also regular diminished gravity,
and we also have the example of the astronauts on the moon, where gravity was
much much smaller.

But I should have guessed that at the height ISS is it's too little to
actually reduce gravity at any substantial way, and it's all the effect of the
orbit/free fall.

------
ertand
I wonder what the procedure to locate the leak was.

~~~
rsync
You spray soapy water all over the outside of the module and watch for any
spots that start bubbling.

~~~
jacquesm
Nah, you spray soapy water all over the inside of the module and watch where
it egresses.

------
moneytide
I've seen several of these "F-35 is a failure" articles over the past few
years, and I have a new theory about it.

Making the opposition think you're weak is a strategy. Straight from Sun Tzu.
Negative press propaganda is a tool in itself.

------
chrishowlin
Would the leak be enough to significantly change the trajectory of the station
such that it needs correction?

Surely the force of the leak is very small compared to the size of the
station, but if it had been leaking for a while the change could add up.

------
mar77i
I've heard that the whole construction up there has been getting leakier over
time. I wonder what exactly the threshold is these days to constitute a "slow
leak"...

~~~
digi_owl
Enough to register on sensors, not enough to trigger an immediate evacuation?

~~~
greglindahl
Even this 1.5mm hole was so small that they didn't bother to wake anyone up,
and instead waited until the next workday.

------
kentiko
"the hole is covered using Alexander Gerst's finger for now" \-
[https://www.reddit.com/r/space/comments/9bi49u/the_iss_is_cu...](https://www.reddit.com/r/space/comments/9bi49u/the_iss_is_currently_experiencing_a_slow/e535dlh/)

~~~
userbinator
A rough calculation of how much it'd hurt (or not): Atmospheric pressure is
10.1N/cm^2, or 0.1N/mm^2. The hole is 2mm diameter, or ~3mm^2 in area, so the
force over that area would be ~0.3N or roughly 30 grams.

It's not a lot of force. I'd be more worried about my skin sublimating,
however.

~~~
SketchySeaBeast
I feel like they'll take a little anti-freezer burn over suffocation.

If only they had an inanimate carbon rod to block the hole!

~~~
Varcht
Are they still taking duct tape up there with them?

[https://www.nasa.gov/image-feature/duct-tape-saves-the-
day](https://www.nasa.gov/image-feature/duct-tape-saves-the-day)

~~~
SketchySeaBeast
Apparently they have already used kapton tape on the hole.

------
jobserunder
Does this mean water is rushing into the space (water) craft?

------
m1573rp34130dy
...perhaps a layer of self assembling/repairing nanoskin?...

[https://www.sciencedirect.com/science/article/pii/S167265291...](https://www.sciencedirect.com/science/article/pii/S1672652911600280)

...or somthing similar

~~~
m1573rp34130dy
yup bad idea alright but i stick by it... maybe someone has a better or more
germane solution than relying on an astronaut to find a leak and patch it up
by hand, but the idea of preemptively mitigating leaks sounds better than
waiting for a problem then correcting if it can be found...

