Life Support
Life support is a general term that, logically, encompasses not only those systems that produce needed resources (e.g. Oxygen, Water), but also those that remove wasteful byproducts (e.g. CO2, Heat); for game purposes, however, it describes the unique sets of systems used to sustain different types of aliens (e.g. Oxygen/CO2), and generally not those that are common to all (known) life (e.g. Food, Water).
There are 3 types of life support in the game:
- Oxygen Atmosphere: For human-like aliens (including humans), Oxygen needs to be produced and CO2 removed1.
- Hydrogen Atmosphere: For Methanogen aliens, Hydrogen needs to be produced and Methane removed2. Hydrogen atmospheres are toxic to Oxygen-breathing aliens, and vice-versa.
- Aquatic: Aquatic aliens live submerged or mostly submerged in Water. Their rooms therefore need additional reinforcement to contain the additional mass and pressure, though these reinforced rooms can be "re-zoned" to either Oxygen or Hydrogen, albeit slower to fill/drain the water.
Insufficient resources
When life support resources (e.g. Oxygen) are insufficient to meet the needs of the station, the game will use a "breadth first" approach to determining exactly where the shortfall lands.
Specifically, beginning in rooms with life support systems, the game will attempt to meet the needs of any occupants in the room first, then the overhead of the space of the room; if there's sufficient resources, the game will then check all rooms connected to the room, and then all rooms connected to those, until it finds rooms where occupants or space needs cannot be met. If a room has sufficient resources for occupants, but not for its space, occupants will suffer minor symptoms (i.e. become unhappy) but otherwise be uninjured; if there are insufficient resources for occupants, they will begin to e.g. suffocate.
Environment suits
Workers are able to equip environment suits to enable them to enter environments otherwise hostile to their own life support needs, e.g. a human Worker who breaths Oxygen can equip such a suit to enter a Hydrogen atmosphere or Aquatic environment; this enables Workers to perform work regardless of where they are, and prevents the game from becoming unplayable if work must be done in one or more environments where the player has no "compatible" Workers.
It takes time to equip or unequip an environment suit, which takes place when the Worker reaches the door between the environments. Movement is slowed while wearing the environment suit; if the Worker is Aquatic, or is non-Aquatic in an Aquatic environment, this movement penalty is doubled. It also takes more time to enter or exit an Aquatic environment.
Technically the atmosphere is about 21% Oxygen and 79% nitrogen, maintained at a pressure at or slightly below 101 kPa (virtually identical to Earth at sea level). For game purposes, however, we discuss only the Oxygen and assume those systems are properly calibrated to maintain the proper ratio and pressure.
A Hydrogen atmosphere is around 20% a mixture of CO2 and Hydrogen, with the balance being nitrogen, at a similar pressure as an Oxygen atmosphere (~101 kPa). We ignore the CO2 component to eschew the problem of designing and using a system where CO2 "supply" means "how much can be removed" in one part, but also "how much can be produced" in another part; like with nitrogen in the Oxygen atmosphere, we assume that Hydrogen life support systems properly manage all 3 gasses. This does, however, open the door to the possibility of systems that e.g. are installed on the boundary between the two atmospheres and remove CO2 from the Oxygen atmosphere at a much more efficient rate (due to it simply being vented into the Hydrogen atmosphere).