Gamemaster Trade (IF)

Solar Hard SF Setting

Trade in the Solar System is shaped less by money than by mass and delta-v. Habitats must constantly import water, gases, and feedstocks to maintain life support and propulsion, while exporting technology, services, or rare materials in return.

Because most manufactured goods can be printed locally, interplanetary commerce is dominated by bulk resources — ice, gases, and reactor fuels — together with a smaller but lucrative stream of high-end equipment and cultural goods.

Distances are vast and transport slow. Cargo moves along predictable orbital lanes using fusion-rocket departures followed by long ion-drive cruises, making interplanetary trade resemble maritime shipping more than terrestrial trucking. Ports, depots, and propellant supplies matter more than speed.

Trade in the Storm Age

Before the Fall, solar power drove interplanetary expansion. Vast mirror farms and photovoltaic grids lit the orbits of Mercury and Venus, feeding the early colonies. When the great solar storms came, those systems failed. Humanity turned to fusion and self-sufficiency, but trade remains vital.

Energy Sources: D–D fusion everywhere; thorium fission on Earth. Solar power is unreliable due to frequent solar storms.

Prime Movers: Fusion rockets for initial acceleration, ion drives for in-transit corrections. Magnetic acceleration for bulk raw materials in long slow trajectories.

Key bulk commodity: Water (ice, liquid, or pelletized).

Secondary commodities: Nitrogen, argon, reactor fuel, industrial metals, and high-end equipment.

Primary trade direction: Water and volatiles flow inward from the Belt; gases and technology flow outward.

Overview of Trade

Mercurian Sphere

Powered by compact fusion reactors. Mercury is a heavy-industry world, short on volatiles but rich in minerals.

Needs: Water for life support and propulsion; carbon, nitrogen, and sulfur compounds to sustain its closed industrial biomes.

Exports: Refractory metals, glass and basalt fiber, radiation-hardened electronics, and Dedalus Project technological salvage.

Venusian Sphere

Serves as the major source of breathable gases and atmospheric buffers throughout the inner system.

Needs: Metals, silicates, and water imports from the Belt and inner asteroids.

Exports: Nitrogen and argon for pressurized habitats, carbon and sulfur feedstocks for chemistry.

Earth (Terran Sphere)

Earth’s power grid is self-sufficient, running on thorium fission — a legacy of stability that survived the Fall. It maintains a massive, well-educated population that dominates any job not time-critical in cis-lunar space, and even beyond when time permits.

Although Earth itself is self-sufficient, the deep-space programs of the Earthforce Commons are not. Their construction projects and exploration fleets demand enormous quantities of materials that Earth, buried in its gravity well, cannot easily supply. These ventures drive continual investment and procurement across the colonies, shaping much of the interplanetary economy.

Needs: Little in the way of raw materials; Earth’s resources remain vast.

Exports: Tourism. Cultural artifacts and experiences — fine foods, wines, artworks (mostly copies), handicrafts, ritual and magic items, mementoes, music, dance, and intellectual property. Highly refined fuels. Biodiversity exports — seeds, breeding stock, and microbial cultures. Also remote labor, skilled emigrants, and trained crews for space service.

Emergency deliveries of carbon, nitrogen, sulfur, and argon is a small but lucrative export restricted for ecological reasons.

Cis-lunar Space (Terran Sphere)

The Moon provides silicates, oxides, and shielding mass. Cis-lunar space is the logistical and political heart of the fusion age, turning Earth’s culture and labor into hardware and governance.

Needs: Continuous water shipments from the Belt and near-Earth asteroids for life support, propellant manufacture, and shielding. Carbon, nitrogen, and sulfur feeds for biomes.

Exports: Fusion reactors, shipyard construction, high-end electronics, coordination of interplanetary logistics, and financial services.

Luna can mine water, but supplies are limited; importing from the Belt is cheaper and preserves emergency stock.

Mars system

The major tourism, entertainment, diplomacy, and higher-education center of the solar system. Trades propellants and argon for nitrogen.

Needs: Nitrogen and specialized metals from Venus and Earth.

Exports: Tourism and entertainment. Propellants (CH₄/O₂), argon (for buffer gas and plasma thrusters), and organic chemicals from CO₂ processing. Tritium from Earthforce operations at Deimos.

Main Belt (Ceres and beyond)

Ceres and the Belt are the volatile capital of the system — the headwater of a stream of ice loads flowing sunward to maintain a steady supply of water to the inner worlds.

Needs: Nitrogen and argon from Venus and Mars; high-tech goods and reactors from cis-lunar space.

Exports: Water in vast quantities, oxygen, carbon, ammonia, salts, and metals. Large ships.

Jupiter sphere

The Jovian system supports frontier exploration as the major hub furthest from the sun. It is highly self-sufficient, like a miniature solar system, with its own “belt” in the irregular moons — making it the orbit least dependent on imports.

Needs: High-end technology and inert gases from the inner system.

Exports: Deep-space propellants, sulfur and organic compounds, and refueling services for outer-system missions. It also provides competition for the intellectual property of Earth — a small market share, but one that keeps Earth honest.

Bulk trade lanes

• Water → inward: Ceres and outer C-types to Mercury, Venus, Earth, and Mars.
• Nitrogen and argon → everywhere: Venus to all; Mars supplies argon.
• Metals → inward: Inner and mid-Belt to the terrestrial planets.
• Technology → outward: Earth and cis-lunar space to the Belt and Jupiter.
• Propellants → outer routes: Belt depots to Jovian and Trojan stations.
• Culture, labor, and tourism → outward: Earth and Mars to cis-lunar space and beyond.

Strategic commodities

• Water: Largest trade good by mass; critical for all habitats and reaction mass.
• Nitrogen: Scarce and valuable; Venus dominates supply.
• Reactor fuel: Deuterium from oceans and ice, tritium fuel breeding.
• Argon: By-product of Mars industry; used as propellant and buffer gas.
• Culture: Earth’s soft power — art, luxury, and labor — exports value rather than mass.

Economic patterns

Inner worlds pay for water and nitrogen, exporting technology and fusion components.

Belt worlds pay for gases and equipment, exporting ice and metals.

Jupiter trades in depot services and specialized chemicals for expansion beyond.

Mercury and Venus remain dependent on imports of volatiles despite their industrial strength, making them permanent customers of Belt ice.

Saturn does not meaningfully contribute to trade except as the recipient of occasional loads of help from Earthforce.

Major Trade Flows

The Solar System economy is dominated by a few large flows of mass and energy. Most smaller trade routes branch off from these.

Origin	Destination	Cargo	Notes
Mercury	Inner System	Refractory metals, ceramics, electronics	High-temperature industry close to the Sun.
Venus	Belt, Mars, outer system	Nitrogen and atmospheric gases	Primary source of nitrogen for habitats across the system.
Terra	Entire system	Cultural goods, skilled labor, high-end research	People, expertise, and cultural prestige.
Asteroid Belt	Inner System (Earth, Luna, Mars)	Water, carbon compounds, metals	Bulk feedstock. Wharves for large ships.
Jovia	Inner System	Hydrogen, helium-3, fusion fuels	Large-scale fuel depots support deep-space operations.