Pourne

Pourne (A-9B2887-A) - Fl

Pourne, like Titan in the Sol system, is a planet-sized moon of a gas giant – in Pourne’s case the gas giant Leodifra. 

Named for the ancient writer Pournelle, this world is ruled by a calcified, paranoid bureaucratic caste who assume that all offworld visitors are probably saboteurs sent to destroy one of their habitats. Pourne customs officials are notoriously aggressive and heavily armed, and Leodifra space is protected by a bristling array of defence platforms. Despite this attitude, its stability and technology level make Pourne is one of the most important trade hubs in the subsector.

Pourne has an active geology and a hydrosphere comprising extensive seas of liquid methane and ethane (covering around a fifth of the planetary surface area) over a planetary crust made up of ice (a mixture of water, ammonia and carbon dioxide) that transitions to a liquid water ‘mantle’ at several hundred km deep and which lies above a rocky core. Pourne’s atmosphere is mostly nitrogen mixed with a small percentage of methane vapour along with traces of argon, neon and krypton – however the high frequency of ice-volcano eruptions (driven by gravitational flexing of the planetary core as it orbits Leodifra) mean that concentrations of vapourous nitric acid are high enough to cause maintenance issues for permanent installations and has caused the planetary atmosphere to be designated as corrosive. A combination of insolation from the F3 V system primary, gravitational heating of Pourne’s core and atmospheric greenhouse effect means that the surface temperature typically ranges between 160 and 135 degrees below freezing.

Despite the harsh environment, Pourne has been continuously inhabited since the initial Solomani colonisation wave during the Second Empire and currently it has a population of nearly a billion sophonts. The bulk of the population resides in Leodifra space - either in the domed cities on Pourne itself (plus the various other moons of Leodifra) or else in orbital habitats clustered at Pourne’s L4 and L5 points with respect to Leodifra. There are also numerous resource extraction operations, scientific stations and observation platforms scattered throughout the system however, so the intra-system traffic is significantly denser than most other systems in the Outrim Void.

As Pourne is largely made up of ice, it is much less dense than a rocky planet of a similar size. Consequently, although Pourne is slightly larger than Earth it only has a mass of a little more than half Earth’s and surface gravity is 0.43G. Grav-plates tuned to standard gravity are commonplace throughout the domed cities and habitats on Pourne and having the ‘belter look’ (characteristic of being raised in low gravity) is a marker for poverty in Pournese society.

Station-1 is one of the largest habitats in the L5 cluster and serves as the principal highport for the system. In addition to extensive docking, storage and maintenance facilities, Pourne Station-1 is also one of the largest shipyards in the region and Pournese-built vessels are commonplace across the coreward half of the Trojan Reach sector and the rimward subsectors of the Spinward March. The Pournese have leveraged the expertise they have built up by surviving (and indeed thriving) in their unforgiving home system over the past few thousand years into a key asset and Pournese corporations are acknowledged as some of the best life-support engineering and hostile environment habitat manufacturers that can be found across the Trojan Reach.

As a long-standing spacefaring civilisation they are also significantly better at ship-building than might be expected from their general industrial infrastructure (the system is rated as TL10, but the shipyards are capable of building and maintaining up to TL12 designs). Pourne’s position orbiting one of the largest gas giants in the Trojan Reach means that there is a substantial fuel refining industry within Leodifran space and massive Pournese refiner-tanker vessels are a common sight across the Drinaxi main.

Other than naval forces lost in the fighting outsystem, the Aslan were reluctant to take on the heavily fortified volume around Leodifra and so the Pournese weathered the Fall of Drinax largely unscathed. The instruments of surrender that they signed required Pourne to permit an Aslan naval base for nearly 22 standard years after the Fall however (a time period equivalent to 25 ftahea) and they were forbidden to offer asylum to several thousand proscribed individuals; chiefly members of the Drinaxi ruling classes. Nevertheless, Pourne was the destination for substantial refugee flows from Drinax after the Fall and today there are a several million Pournese citizens who are either survivors or descendants of these Drinaxi emigres. This means that the marked hostility towards offworlders (particularly Aslan) that the Pournese are notorious for is significantly reduced in the case of Drinaxi or Asimen spacers.

Pourne System

Pourne Prime is an F3 V main sequence star that casts a jump shadow out to 1.18 AU (~177 million km), however because the main world orbits Leodifra, a gas giant that orbits at a little over 12 AU from the primary in the outer system, destinations are very rarely (<1% of the time) masked by the star’s jump shadow and ships generally only need to worry about boosting to Leodifra’s 100D limit – this is a distance of 13.6 million km, which takes ~20 hours to cover at 1G, falling to 8.4 hours at 6G. The planet Pourne is separated from the L4/L5 habitats (including Pourne Station-1) by about 2 million km (a distance requiring nearly 8 hours to transit at 1G or a little more than 3 hours at 6G).

As the majority of the system’s population is in Leodifra space, this is where the main concentration of system defence forces are also stationed, with a substantial naval presence bolstered by planetary and orbital bases. However the Pournese Navy also maintains permanently manned bases on or near all of the planets in the system and squadrons of well-armed SDBs regularly conduct patrols through the outer system.

System Parameters

Minimum Orbit	Inner LZ	Outer LZ	Snow Line	Max Orbit
0.28 AU	1.9 AU	2.5 AU	10.3 AU	56.8 AU

Planetary Orbits

Orbit	Distance	Name	Type	Size
1	0.84 AU	Anmedesa	Terrestrial	9600 km
2	1.19 AU	Jerhewa	Terrestrial	8000 km
3	1.54 AU	Renon	Terrestrial	4800 km
4	2.24 AU	Anko	Terrestrial	6400 km
5	3.64 AU	Ezehovo	Terrestrial	1600 km
6	6.44 AU	Tayere	Terrestrial	9600 km
7	12.04 AU	Leodifra (Pourne)	Gas Giant	136,000 km
8	23.24 AU	Chadiso	Terrestrial	20,800 km
9	45.64 AU	Souserala	Gas Giant	48,000 km

Vessels can perform wilderness refuelling at Souserala where the significantly smaller jump shadow compared to Leodifra reduces the time required for skimming operations by about a third, however the high cadence of Pournese Naval patrols throughout the system means that ships will frequently encounter a patrol cutter on station, or even a full SDB flotilla (with attendant tender and tankers) conducting a sweep for smugglers or pirates.

Glossary

Ftahea = the Aslan standard year, approximately 320 standard days