Atmosphere

Atmosphere

Specific heat	Variable

Description

Atmosphere is a environmental system consisting of contained substances in gaseous or liquid form, with a set of variables, that are interpolated from the properties of these substances into a single value across the entire system. Atmospherics is one of the main simulated systems in Stationeers. The game world consists of many individual volumetric units of atmosphere, that interact with each other, as well as artificial structures and items, that are in contact or indirect interaction with them. Every time a player creates a new container, pipeline, or gas-operated device, a new atmosphere is also generated to track its content and variables for as long as it exists.

As a term, Atmosphere is mostly used as reference to exterior and interior world spaces, each having their own volumetric unit - atmospheres associated with pipes and relevant devices and machines are referred to as "pipe networks", "gas networks", or just "networks". Atmospheres associated with containers are just called "contents". Despite the difference, these atmospheres are not different in principle and are guided by the same variables and rules.

Atmosphere Properties

Each unit of atmosphere simulates a number of properties, these properties generally change over time as the atmosphere interacts with the surroundings. Some of these properties may not be available for a specific type of an atmopshere if they has no relevance for the physical interactions and dynamics.

Contents

Each unit of atmosphere contains its' own composition of gasses and liquids represented in quantity by mol. Common gasses are Oxygen, Volatiles, Nitrogen, Carbon Dioxide and Pollutant. Since the "Go with the flow" update, Water is no longer present in atmosphere, and can no longer exist in the form of gas. Water is now part of a separate liquid system. Since some time after the "In world water" update, Water is now able to be in the atmosphere as any state again.

Volume

Volume is a compound spatial dimensions of a given atmospheric system, whether open or enclosed, measured in metric Liters (L), or a 1 cubic decimeter. Pipe networks will expand dynamically in accordance with interconnected pipe segments, while other containers have their specified volumes. Volume defines the amount of substances that can be stored and cycled through the atmosphere under the same pressure, and especially significant for liquids, which have a fixed density and cannot be pressurized.

Functionality of many interface devices is tied to the volume of the input atmosphere (rather than the amount of contained gases), so it can be beneficial to split these systems further to improve efficiency. Very big volumes, like station interiors, large Tanks, and extensive pipe networks may take an obnoxious amount of time to empty out, despite holding relatively small amount of gases due to low pressure. Player should take heed of that and not expand the volume of functional systems beyond what is actually needed for them to work.

Temperature

Temperature is a degree of potential energy stored across all of the contained substances, measured in Kelvin (K), or Celsius (C^o). Temperature is passively exchanged between two adjacent atmospheric systems through emitted EM radiation (referred to as "convection"), as long as they are not insulated, until the temperature equalizes for both. Temperature can also be emitted into the atmospheric vacuum (referred to as "radiation") although at a very slow rate. The higher the difference in temperature and the greater the contact boundary between two systems, the faster thermal exchange occurs. Both methods of thermal exchange can be accelerated through the use of respective Pipe Radiators.

Artificial structures in Stationeers have an arbitrary immunity to extreme temperatures; However, such structures and devices also possess an Autoignition value, meaning that an item or device containing a sufficiently hot atmosphere, or itself being contained within one, will react with oxidizers (if present) and burn down irreversibly. Extremely cold environments in turn will cause power storage devices to lose their charge over time. Living things have a relatively narrow comfortable temperature band with an average of 293 K (20 C^o), beyond which temperature may cause continuous health damage and eventual demise.

Pressure

Pressure is a product of the volatile contents of the atmosphere adjusted by temperature measured in Pascals (Pa), with 101325 Pa measuring a standard Earth's atmospheric pressure at sea level.Gases produce the pressure from the molar amount of gas multiplied by the system's temperature. Changing temperature will also change the pressure accordingly, while raising the pressure has no effect on temperature, as long as the introduces gases have the same temperature themselves. If two atmospheric systems are directly connected, the gases from both systems will move in-between them to equalize the relative content, until both system are completely homogenous. The difference in pressure accelerates that movement, causing loose objects and player to get pulled and flung about by the flux. Flux of gases between open atmospheric systems is indicated by the particles travelling from higher-pressure to lower pressure regions.

Higher pressures are often associated with increased efficiency of most atmospheric machinery, as it allows to increase the input volume of the processed gases; Inversely, high pressure on the output side of such machine lowers the efficiency, as it will have to brute-force its output against greater resistance. Deliberately forcing high pressure is commonly utilized in order to condense gases into a liquid state. Liquified substances produce no pressure themselves, but will often passively evaporate in response to lack thereof.

Constructed elements like walls and windows, pipe networks, and atmospheric containers, all have a specified Pressure Differential value, which defines the net difference of pressure between internal and external atmospheric pressures that they can endure. Reaching beyond that limit will cause these entities to suffer structural damage and break (overpressurization). Portable containers in particular, which rely on homogenous tensile resistance to endure pressure, will explode violently, which may lead to irrevestible area damage and chain reactions, and have to be handled with extreme care.

In general terms, an enclosed container with greater volume has lower pressure resistance for the same materials used. Living things also require a specific range of native pressure to survive, although its not as strict compared to comfortable temperatures. Barotrauma effects are disregarded.

Specific Planetary Atmospheres

Planetary atmospheres are a set environmental conditions that are shared across all exterior space at a given location. They're effectively permanent, containing indefinite supply of gases at self-sustained and self-correcting values. As such, a planetary atmosphere can be exploited as a source of substances, as a heat sink, and/or as a waste dump for undesired gases. Atmospheric values may change based on the time of day and temporary weather conditions. A cold atmosphere can be used as an infinite coolant in its own right. A hot atmosphere can maintain the heat within a Furnace, or even act as smelting medium for processing metals. Finally, a vacuum is an everlasting void, which will quickly dissipate any amount of hazardous gas dumped into it, and a natural thermal insulator.

Nevertheless, the primary purpose of building the station in the first place, is creating an isolated habitable and workable space in otherwise unwelcoming environment. Different planetary atmospheres will impose their own challenges for continuous survival.

Planet	Pressure	Temperature			Gases
		Celsius	Kelvin		Carbon Dioxide	Nitrogen	Oxygen	Pollutants	Volatiles
Moon	Nil	N/A	N/A
Mars	2 - 3 KPa	-53 to 19	220 to 292		95%	3%	1%	1%
Europa	44 to 47 KPa	-149 to -140	124 to 133				100%
Mimas	Nil	N/A	N/A
Vulcan	24 to 56 KPa	127 to 665	400 to 938		21%			26%	53%
Venus	239 KPa	464	737		93.1%	6.9%		0.016%

Large Grid Atmosphere

The most common type of atmosphere is the large grid atmosphere. Game world is outlined by an orthogonal grid of 2x2x2 meters, and every such grid cell (the size of a Frame) contains its own atmospheric system. Volume of that system doesn't decrease when artificial structures with their own volume are placed inside, however it can be partially displaced by full terrain voxels. The atmosphere in one large grid will exchange contents and heat with neighbouring atmospheres in order to equalize their content. An atmosphere in a vacuum will eventually spread out and dissipate in within a few large grid atmospheres of distance.

Pipe Networks

Each individual pipe network is simulated with one atmosphere. If you break up a pipe network with a device such as a pump or valve, you will create another network, and the installed device will interface the interaction between both.

Structures

Individual structures that contain atmospheres (static tanks, etc) will interact either with a pipe network or directly with the surrounding atmosphere, it depends on the configuration. Depending on the functionality of a structure, it can contain its own internal atmosphere (like Furnace or Gas Generator), or act as an interface between connected networks (like Valve or Filtration unit). Structures that containe their own atmosphere will dump its content into the local large grid environment when disassembled, so make sure to drain it completely into a pipe network or a portable container ahead before uninstalling.

Items

Some items in the game contain their own units of atmosphere, such as Canisters, Suits and even the players' Lungs. Items with atmospheres, just like other atmospheres, can be heated by direct sunlight, leading to canisters bursting by pressure, or fuel autoigniting(exploding) at high pressure/temperature.

Gases and Liquids
Elements	Compounds	Mixtures	Other
		Fuel (66.6% H2 + 33.3% O2) Superfuel (50% H2 + 50% N2O) Air (75% N2 + 25% O2)	Atmosphere Coolant