Infrastructure – Life and Atmospheres It was our original intent to do away with planetary sales of Lifeforms (aka Life Demand) on worlds which was why over the years there has been very few items added to the category. Unbeknownst to us however there has been a thriving market in the production and sale of Agricultural Implements, fulfilling Life Demand across the Peripheries (despite conjecture we are not omniscient). This is something of an eye opener for us and caused us to re-evaluate the category. The conclusion drawn was that doing away with this field would be a disservice to the game and rather it would be better to develop Life Demand and integrate it into the developing infrastructure upgrade. What is Life Demand? While trade goods are relatively straightforward, simply being items that are desirable to planetary populations, Life Demand represents something more nebulous. It covers agricultural demands, from seeds, cattle, farming equipment through to recompense paid by civilians immigrating into the world. It does not however include slaves, so the ‘selling’ of civilians to the planetary economy should not be confused with selling people. It also includes demand for investment into the world. It essentially represents revenue that the infrastructure can spend on importing items without setting back the economy.

Like Trade Demand it has two primary components, the amount of stellars that the world can absorb per week (MAX INCOME) and a stellar multiplier (VALUE/MU).

TRADE VALUES	MAX INCOME	VALUE/MU	LOW VAL	HIGH VAL
Trade Goods	21683	1.88	7.3	15
Drugs	0	0	0	0
Lifeforms	68500	2.38	9.4	18.2

The max income component is based on the quantity and type of sectors that make up the world. The value/mu component represents the compatibility of the environment with ‘terrestrial’ life as standard sentient life forms in Phoenix are adapted to Earth-like worlds. As with trade, the value of items sold to the world is equal to the basic value of the item multiplied by the value/mu and again by their distance modifier (if unique).

How are the numbers calculated?
Max income is based on the quantity and type of sectors. The table below gives the value of each sector type. If the sector is not listed below, it does not contribute to the max income.

Terrain	Stellars
Tundra	15
Sea	25
Shallows	95
Plains	120
Jungle	165
Forest	185
Grasslands	200
Cultivated	2000 (maximum quantity contribution is Population Stage x (Population Stage +1), i.e. 2 for Initial Colonisation
Urban	10000 (maximum quantity contribution is (Population Stage -1)^2 i.e. first at Advanced Colonisation

The contribution to max income for life items from urban cultivated sectors is shown in brackets:

Merchandising	Calculated	Actual
Life Max Income:	116665(16000)	68500

As can be seen a huge world of grasslands with the appropriate quantity of cultivated and urban sectors nets the maximum potential income because there are plenty of places suitable to live for an advanced interplanetary culture. Building more cultivated and urban sectors than are strictly needed is possible, though converting grasslands into farms and cities that are simply not needed actually devalues the world. A reason to do so would be to split up the population, making it less of a tempting target to terrorists.

Note – people have historically dropped nukes on and otherwise bombard cultivated and urban sectors. It is our intention to make this action a standard order at some point now that we have a much more accurate representation of planetary infrastructure. We will soon (in 2015, fingers crossed) be able to ‘spawn’ appropriate urban sectors as a pseudo base, include targeting lists and even ‘sublime’ the sector back into the infrastructure post combat, updating the planetary infrastructure as appropriate. It will certainly give a good reason to build platforms. No point in shielding a base and leaving the population to be blown to pieces.

Value/mu however takes into account the world environment. For a goldilocks world the value/mu is 2.1. As the world diverges from this perfection, the number drops. Each facet of the environment is treated separately. This is shown on the audit world report. The reason for showing the negative contributions for each aspect of the environment is that it allows the players to consider if terraforming is an option.

For example – consider this asteroid:

Environment	Value	Inf Increase	Life Value/mu
Gravity	0.03 (Low)	38.5%	-0.97
Temperature	44 (Low)	115.5%	-2.51
Tectonic	26 (High)	16%	-0.21
Radiation	0 (Normal)	0%	-0
Atmosphere: Thin (0)
None	100%	100%	-2
World Status: Divergent, terraforming sectors restricted.
Merchandising	Calculated	Actual
Life Max Income:	0(0)	0
Life Value/mu:	0	0

This airless rock has a very low gravity and temperature. As a consequence it can be seen that it has an overall value/mu of -3.59(=2.1-0.97-2.51-0.21-2) which is less than 0.

Terraforming could be used, getting the world to spin, hollowing out the interior, increasing temperature and filling the world with an atmosphere. These might be sufficient to mitigate the penalties. Then with a stage 2 population build an urban sector and enjoy 10k stellars a week with a nice value/mu on top of all the other benefits of having an advanced colony. The question is though whether this is worth it (unless you are a pirate).

Atmospheric Density
Optical depth is a measure atmospheric transparency. In game terms we consider this to be the product of three components, the atmospheric composition, the temperature and the thickness of the atmosphere. As such, when accounting for composition and temperature, it equates to thickness which in turn can be used to determine approximate surface pressure for the purpose of infrastructure.

Note that gravity plays only a minor role in determining atmospheric pressure. Cold worlds can still have dense atmospheres. The moon Titan has a pressure almost 50% higher than Earth yet has gravity 1/7th that of Earth and 1/3rd of its temperature (in Kelvin).

Using the existing range of optical depths for terrestrial and near terrestrial worlds produced a relatively reasonable scale on which 19 has been set as the optimal optical depth producing a surface pressure range suitable for infrastructure (on worlds that do not need domes). The normal range has been set between 14 and 24 outside which atmospheres will be described as dense or thin as appropriate. Further, the optical depth will modify the partial pressure of all the gases in the atmosphere which will influence their effect on both infrastructure and life. A dense atmosphere will have a lower optimal oxygen % though some places such as Capella in the Capellan system are still woefully low. Thin atmospheres by the same token require higher oxygen content. For worlds similar to terrestrial (virtually all nitrogen and oxygen), consider the true oxygen % (compared with 21% for a standard terrestrial world) to be equal to the 02% x sqt(optical depth/19). So for example, Capella has a modified oxygen abundance equal to 3.8%(=3xsqt(31/19)), still far short of 21%. Maybe O2 nasal breathers are used by those that go outdoors or possibly pills are taken to increase oxygen uptake.

Example of a dense atmosphere

Environment	Value	Inf Increase	Life Value/mu
Gravity	1.05 (Normal)	0%	-0.05
Temperature	303 (Normal)	0%	-0.08
Tectonic	9 (Normal)	0%	-0.04
Radiation	0 (Normal)	0%	-0
Env Damage	42 (Normal)	0%	-0.07
Atmosphere: Dense (28.22)
Nitrogen	86%	0%	-0
Oxygen	14%	1.97%	-0.26

Other atmospheres are a lot more hostile than low oxygen atmospheres and even a complete lack of an atmosphere. These downright unpleasant worlds can have high value/mu negatives even for a modest atmosphere %. Scrubbing these from the atmosphere is likely the first port of call.

Some worlds are just plain hostile – a typical hell world

Environment	Value	Inf Increase	Life VALUE/MU
Gravity	1.522(High)	16.1%	-0.522
Temperature	810 (High)	247.5%	-5.15
Tectonic	72 (High)	62%	-0.67
Radiation	0 (Normal)	0%	-0
Atmosphere:
Sulphurous Compounds	76%	185.08%	-4.63
Nitrogen	24%	0%	-0
Oxygen	0%	11%	-1.5
Merchandising	Calculated	Actual
Life:	0(0)	0
Life Mult:	0	0

Changing Atmospheres
While an atmosphere surrounding rock worlds is often tens to hundreds of kilometres thick, the vast majority of it is within a few kilometres of the surface. Further, certain gases are quite dense and as such their % represents their contribution at ground level rather than for the entire thickness of the atmosphere. For game purposes we are content to allow changes to be made to the atmosphere within a relatively short period that in reality would likely take decades, centuries or even longer. The simple logic behind this is that it makes for a more interesting game and damn the science. This is one of those areas where the game borderlines pulp sci-fi. This does not mean that it is extremely easy or even cheap, merely feasible in some cases.

There already exist in the game various plants and other compounds that can change an atmosphere either through absorbing or exuding certain gases. Many of these have pre-requisites such as temperature range, existing gaseous compounds, specific terrain and possibly even gravity sensitivity. Details can often be found in the plant tech manual though some may require involved knowledge garnered from exploring the origin world of the plant. Absorbers are often pelagic for the simple logic that the gas removed from the atmosphere has to be locked away and what better method that the death of the plant sinking to the bottom of the ocean to be buried in silt for the foreseeable future. Terrestrial floras capable of rapidly changing an atmosphere though rarer do exist. They generally achieve the change through converting the gas so either an inert gaseous compound or into a non-gaseous compound that either becomes part of the plant or is deposited. Microbes in the soil are classic examples, producing sulphuric acid that then drips into the subrock.
In all cases the plant will require a time period to work based on the nature of the atmosphere and other environment conditions. Further there will be a minimum mass required. It is rare that using multiple times this requirement will give any benefit as biofeedback normally causes the plant to reach equilibrium point with the environment. When seeded, there is generally evidence of the changes being reaped on the world, easily picked up in a low pass scan and in some of the more outrageous examples such as the use of vines, in the orbital message.

Due to the sheer quantity of parameters involved in changing atmospheres, this area of the game is dealt with through special actions and is not really for the novice explorer.

Gardening
A sector represents a variable area of a planetary surface depending on the planet type. A sector of a moon for example is normally considered to be much smaller than a sector of a planet while a sector of a gas giant is considered to be tens if not hundreds of time larger than those of a planet. Typically a sector on a planet is roughly 500km to 1,000km square (250,000 to 1M square kilometres) – sufficient to fully circumscribe Great Britain. The sector description therefore represents the most significant terrain of the sector, not necessarily the most common. Molten rock for example may refer to a sector with a few active volcanoes or possibly a fault that is spewing basic lava. These may only represent 1% of the actual terrain area but are by far of greater interest to an exploration team. Urban and cultivated sectors by the same reasoning also dominate the sector though the reality may be little more than a few hundred square kilometres of fields, a few roads and sufficiently cleared vegetation to allow a starship to land without causing a forest fire.

Shouldn’t this mean that a grasslands sector on a goldilocks world is worth more than one on borderline inhospitable world? Yes, and it does due to the life value/mu factor.

Often a world will have less valuable terrain for the purposes of life demand. Cold arid plains, bare crust and desert. Historically we have allowed changes to the terrain through special action and the exhaustive use of structurals, life items and flora of some description. We will be changing this based on the mechanics used to seed Coreward Periphery thereby preventing the conversion of Tundra sectors to Jungles. For the moment though we will honour previously agreed requirements.

The mechanics however will be put in place allowing to convert one type of sector to another based on local temperature (planetary temperature represent average equatorial temperature), current terrain and desired terrain and the world status is terrestrial. Divergent worlds will require investigation to determine the exact limitations on terraforming sectors. Inf Increase This stands for the % increase in infrastructure requirements for the integration of all tech and planetary stage upgrades. Note though that this is capped at 100%. In the above example of a hell world, the total % increase surpasses 500%. Why show these numbers if it is capped out at 100%? For some worlds it may be reasonable to tackle various facets of the environment. A world with a high gravity, a high temperature and a hostile atmosphere may not be worth terraforming even though both the atmosphere and temperature are readily fixable, simply because the oppressive gravity will still result in a high infrastructure increase. Showing each component of the infrastructure increase allows the player to see what can be achieved. This is dealt with in more detail in the article on Upgrading Infrastructure.