Ostranauts Life Support — O2, CO2, Heat and Pressure
✔ Last checked: 2026-08-04
A breathable ship needs four things: oxygen supply (pump + O2 canister), CO2 removal (scrubber + cartridges), heat (heater + thermostat), and an alarm so you notice before your vision does. Ostranauts simulates gas per-tile with real-ish physics, which is why half of all “life support is broken” posts are actually thermodynamics working as intended.
The core loop of breathing
| Job | Hardware | Notes |
|---|---|---|
| Add O2 | Gas pump + O2 canister | ~20 kPa O2 is the wiki’s minimum viable figure (re-verifying for 1.0) |
| Remove CO2 | CO2 AtmoScrubber + LiOH cartridges | Chemistry is real: LiOH → Li2CO3 + water. Budget ~1 cartridge per crew per day |
| Keep it warm | Heater + thermostat | Cold gas = low pressure. Heater near your pumps is standard practice |
| Know when it fails | O2 alarm | Cheap, salvageable everywhere, non-negotiable |
The cold-room trap deserves repeating: pressure scales with temperature. If your pump has moved kilograms of gas and the gauge still reads low, the fix is a heater, not another canister. This single fact resolves a remarkable share of common “not working” complaints.
Coolers are the opposite case — mostly needed when a fusion reactor or hot cargo is dumping heat into the hull.
EVA suits: life support you wear
Your pressure suit traps a bubble of whatever atmosphere you sealed it with, then keeps it viable on battery power and O2 bottles. Practical rules from the official guide and six years of community grief:
- Check the battery before every EVA. A dead suit stops managing your air. Red indicator lights mean turn around now.
- Carry a spare O2 bottle on long salvage runs; swap when the suit warns you. (Since v0.15.1.20, crew AI will even swap their own empty bottles.)
- Reset your air by returning aboard and removing the helmet in good atmosphere — the suit re-traps a fresh bubble.
- Suits also insulate against the cold — relevant on powered-down derelicts, where “no heat” is the default state. See salvage for derelict-boarding practice.
Fitting life support into a new build? Pumps, canisters, batteries and chargers together define an Engineering room — placement details in rooms.
FAQ
What's the minimum life support setup for a ship?
Wiki-documented minimum viable atmosphere is about 20 kPa of O2, which takes a pump, an O2 canister and an O2 alarm — plus a CO2 scrubber once you're breathing in there regularly.
Why is my pressure low even though the pump is working?
Temperature. Gas behavior is realistic: cold gas means low pressure. If kilograms of gas are in the room but pressure reads low, the room is too cold — add a heater on a thermostat.
How many scrubber cartridges do I need?
Roughly one LiOH cartridge per crew member per day, per the wiki. Stock accordingly before long hauls — hypercapnia sneaks up fast.
Do I need a cooler?
Usually only if you run a fusion reactor or heat-generating cargo. Basic salvage ships mostly need heaters, not coolers.