Oxygen

Oxygen is an Astroneer's most vital resource, as it is the only absolute requirement for survival. If an Astroneer is without oxygen, they will begin taking damage and eventually die of suffocation.

Throughout the game, oxygen is represented by a light blue color.

Monitoring Oxygen
An Astroneer's backpack has a built-in oxygen tank capable of storing about 70 seconds-worth of oxygen. Its current oxygen level can be monitored using the bright blue bar across the top of the backpack, or through the audiovisual indicators that pop up when reaching the 50% and 25% marks. When close enough, the backpack will automatically connect to nearby oxygen supplies to refill itself.

Modules
Main Article: Modules

Initially, the most straightforward and readily-available source of oxygen is the habitat module, which produces oxygen at all times. The habitat will extend this oxygen supply to any additional modules as they are built, effectively making an Astroneer's base a safe-zone where one can work without fear of suffocation.

Vehicles
Main Article: Vehicle

As an Astroneer gathers new resources and researches new technologies, they'll eventually find themselves able to construct vehicles. Like the habitat, vehicles are capable of producing an endless supply of oxygen, and will do so even when their batteries are completely empty. This allows for far-flung exploration missions and other remote operations without fear of running out of oxygen.

Tethers
Main Article: Tether

Tethers do not technically provide oxygen, but they are capable of carrying oxygen from a habitat (or any connected base module) or vehicle to an Astroneer's backpack. Compact and affordable, tethers are the single most cost-effective way to extend your oxygen network, particularly in tight or treacherous spaces where a vehicle would be difficult to maneuver. Tethers that are connected to an oxygen supply will be illuminated a bright blue, while disconnected stretches will turn grey.

Tanks
Main Article: Tank

Tanks are crafted items that can be equipped to the backpack to increase an Astroneer's oxygen reserves. They essentially operate as an extension to the backpack's primary oxygen tank, emptying first when disconnected from an oxygen supply and filling last when connected. Each small tank holds exactly as much as the primary backpack oxygen tank.

Oxygen Filters
Main Article: Oxygen Filters

Oxygen Filters are crafted items that can provide a brief safety net in the event of running out of oxygen. An Astroneer with a filter equipped to their backpack will be able to survive longer without oxygen before succumbing to the effects of suffocation. Filters notably hold an effective eleven minutes of air, but can only be attached to the backpack for 80 seconds before being used up.

Trivia
In the in-game Astropedia, Oxygen was listed as an atmospheric resource. This has led people to believe that Oxygen was planned to be an atmospheric resource in 1.0. This was fixed in Patch 1.0.7.

Oxygène 氧气