I rather expected that hangars are in vacuum, at least partially due to them being made out of tritanium which has stability problems in warm atmosphere.
Good point.
(I've confirmed with Ulf that the "them" here refers to the ships rather than the hangars. I've also confirmed that when you build a player-owned station it's tritanium-based, which raises the prospects of either trit-walled hangars or a lot of non-trit-based internal fit-out.)
I
think the original metagame reason for trit being unstable at atmospheric temperatures[1] was to explain why our spaceships stayed in space and didn't do planetary stuff. With the increasing addition of planetary stuff to the player portfolio, there hasn't really been a reckoning with this ancient piece of information. Maybe alloys or annealing or surface treatments are improving to the point where trit can now be used in ways that don't rust/burn/explode/do-whatever-it-did. *shrug*
(I note that metallic alumin(i)um is highly reactive: so reactive that it oxidises almost immediately, which usually means it makes itself a nice, stable oxide coating and we think of it as benignly inert. But if it were that easy to stabilise tritanium, why would you mention its instability?)
I do get the sense that CCP's in-house view of hangars involves air. I'm trying to work out ways to connect the dots here that make sense, since my first impression of the proposed architecture would have the air and blankets from my CQ blowing out the hangar door when I undock a ship.
I also expect that there's magical forcefields that hold the air in and stop it escaping, so you can stand on your balcony and not need a pressure window between you and the vacuum.
So, no stations don't vent air when ships undock.
You may be right, but you're asserting rather than describing a possible mechanism and I'd like a mechanism here. Can we come up with a way this might work that doesn't require (too) liberal applications of handwavium?
I'm pretty sure that stations have large plant growy bits - if you look at some of them closely you can see what look like gardens or parks with windows on them. That might be enough for oxygen replacement, or it might be suplemented with extracted oxygen from various icebelt minerals, or more industrial hydroponics sections.
I'm not
quite interested enough to start doing some crunchy stuff here, but if I were I'd look at calculations from modern closed biospheres as a baseline for what it takes to support the needs of each person and process on a station, and from that I'd project the amounts of gasses that need to be generated, recycled or imported to support the stations we know and love.
What blend of gasses do submarines use? It's just ordinary liquid nitrogen/oxgen "air", isn't it? Are there good reasons you might use something different? Where might you source lots of nitrogen? Mining the traces in some planetary atmospheres?
* Matariki Rain wanders off with visions of the lives of a nitro miner and a station manager dancing in her head...
[1] Note to Ghost: Temperatures, not pressures. Pressure or water-vapour or whatever would have made a lot more sense than temperature, which could be expected to shift through the unstable zone fairly often in our spaceflight.