Sandstorm underground?

[Ghost Engineer]

I'm on Mars and I dug myself a mineshaft under my base with an autominer. I figured if I sealed the top I wouldn't have to deal with sandstorms. I wasn't gonna pressurize the entire mine, but it would be nice to just be able to calmly mine stuff while there's a storm going on.

Sadly, it looks like the sandstorm is also raging underground, all the way to bedrock. The shaft looks sealed but the temperature changes with the time of day so I assume it's not airtight.

Is it just too big of a space to be airtight (or at least safe from storms) or am I missing something else?

[JeanDeaux]

The terrain provides zero protection from the storm, there are no calculations currently being made that divert the storms fury from everything on the planet. The only protection from the storm is within structures you build and provide a variation to the world atmosphere; simply enclosing an area doesn't do the trick.

[Ghost Engineer]

I'll test this tomorrow on a smaller space, but I'm pretty sure the storm does not affect airtight spaces, even if their boundaries are partially made out of terrain.
I found a claim somewhere online that if an encolosed space is over 1000 frames in size it is considered 'outside' no matter what. Game just doesn't calculate airtightness for spaces that big. This might be the case here.

[JeanDeaux]

I'll point you to the Dev's response to this atmospheric glitch. The 1000 frames may be a thing, but I thinking that's probably a much older claim made prior to the refactor.
https://steamcommunity.com/app/544550/discussions/0/3464975249557735859/

[Ghost Engineer]

Oh, I get it now. Your post was just a bit unclear. Thanks for the info.
I dug out a lot of space in the mine and the pressure dropped from 2kPa to 1. Guess it's airtight after all.

[wildsoft]

Ph, I used to do this on Europa on a hard difficulty, yes you can.. or at least you used to be able to do it. I have not built a underground base in a while, but when I did it was fine, you just need to seal off the base airtight... one it's airtight, it acts like an interior. Europa's main difficulty is the cold, and the power... And drinking... plan was to build the base by digging into a mountain or crater at a 45 angle. Then you can erect a small room very fast and drop a load of flares and hope it's enough to heat up quickly. entrance gets a airlock plus double door and wall between both and on top with the structures sealed off, then you weld the simple walls in on the first 2 around it... so that it "digs" into the mine. then you can test this airtight by letting off some oxygen to see if it escapes. if its air tight, you should see temps slowly climb up. You have on average on Europa about 15 minutes to get a base up with temps equalized to survive.