Gamemaster Second Orbital Zone: Venus (IF)

Solar Hard SF Setting

Venus at a Glance

Venus is a world of extremes, locked in a slow, strange dance with the Sun. Its day lasts longer than its year, creating long periods of relentless sunlight followed by equally long darkness. The atmosphere grows denser and hotter closer to the surface, crushing and toxic, dominated by thick clouds of sulfuric acid. This hostile environment shapes every aspect of life and technology, forcing colonies to cling to the high-altitude cloud layer where pressure and temperature become more forgiving, and where survival depends on constant adaptation to a volatile, alien sky.

Atmosphere

The dense atmosphere below provides strong shielding from radiation, allowing radio and other electromagnetic signals to travel downwards from cloud cities to the surface and lower layers. This makes Venus one of the few places in the inner system where exploration drones can work remotely over long distances. However, storm ionization layers scatter up-looking sensors; orbital-to-cloud links must be optical through weather windows or tether relays. Ships orbiting above the atmosphere can not reliably use electronic sensors to look down, nor can the cities effectively scan or communicate upward into space. This creates a natural electromagnetic “blind spot” between space and the cloud layer. This is where the cloud cities of Venus thrive.

Colonization

Venus colonization pre-Fall consisted mainly of floating cities high in the atmosphere (50–60 km), where pressure and temperature are Earth-like. These cities hosted advanced biotech research and limited bio-industry, exploiting Venus’ extreme environment as a natural lab. You can survive outdoors here with just a breathing mask and acid-adapted skinsuit.

After Icarus Fall, surface and lower atmosphere installations were lost or abandoned and many cloud cities collapsed and fell. Twenty years on, Venus has roared back. The cloud layer is once again crowded with aerostat refineries, tethered “skydocks,” and linked city-clusters exporting what the inner system lacks — carbon feedstock from CO₂ cracking, sulfur and sulfuric intermediates, nitrates, industrial gases, plastics precursors, and specialty reagents. Pre-Fall lanes are re-charted, customs is digital again, and Venusian combines bid contracts across Mercury, Terra, Mars, and the Belt.

Cloud cities

Held aloft by huge balloons suspended by lifting gasses, preferably H₂, but other gasses can be used in a pinch. This can be scaled, but the shell of the gas cells come under strain, limiting a cloud city to about 10.000 tons and about as many people. This means everything in a cloud city is light, almost to the point of being flimsy. Sound privacy is a a luxury, heavy industry is avoided, and shuttles are kept medium-sized or smaller. The living area is below the envelope, sometimes in a flat platform, other times following the underside of the lifting structure. Landing pads are sometimes on top of the envelope, but more commonly on arms extending out from the living area.

Safety and migration

Solar weather, Venus storms, natural acidic rain, all wear on the cloud cities, and they try to dodge these with their limited maneuverability. Operations run on forecast corridors, relay aerostats, and no-heroics doctrine. The main way for a city to steer is to rise or sink to catch a layer moving in the desired direction; there are a few other tricks but these are minor. Maneuvers are local and limited. Drifting on the prevailing wind dominates, making the practical day-night cycle of a cloud city is 4-5 days, completely different from the 117 day cycle on the surface.

Power

A cloud city wants to avoid anything that is heavy. This is a problem for power generation. To avoid heavy shielding, D-T reactors are avoided and D-D reactors are mounted on tethers below the city, using polyethylene blocks and distance instead of conventional shielding.

Venus is one of the few places in the system where solar power is still somewhat viable pst Fall. High-flying cloud cities open up like flowers, showing square kilometers to the sun. Lightweight super-conducting batteries store power, optimized for capacity rather than explosive power.

Different heights, different roles

Radio works inside Venus' atmosphere between cities and down to the surface, but not to orbit. Orbital communication uses microwaves, but this is unreliable; atmospheric interference and the random ways wind move cities around create communication shadows.

The higher you are, the less lift you get from the thinning atmosphere, but you get more solar power and better communication with orbit. High cities host communication hubs, solar power, commercial agents, flight control, and tourism. Deeper down cities carry more load and are more industrial.

Specialization and clusters

Cloud cities are small, from 5.000 to 20.000 tons. You can form clusters, but have to separate during storms, and it can be hard to re-form the same cluster, its easier to just bunch up with other cities that happen to be near. These are unpredictable social occasions, sometimes even carnivals, meeting new people and forming new relationships.

Because of this enforced isolation, every city tries to be as self-sufficient as it can. Industrial cities have less people and more machinery, service industry cities the reverse. Each handles its own basics, power and life support, but beyond that they also try for economic independence. Rather than being clusters for many industries, each city focuses on a specific job to gain what scale benefits it can. In this way they are more like floating mill towns than true cities, making them sensitive to market cycles. Trade between cities is as important as exports and imports.

Surface and Low Atmosphere Operations

Accessing the lower atmosphere and surface is very dangerous because of pressure and heat, but exploration, science, and special resource extraction means this is regularly done by drone.

Parachute down, balloon up

Pods go down by chute and return by balloon. All have an emergency secondary balloon and radio for safety. There is great risk and little reason for a human to ever go down.

Balloons use stored H₂ as the lifting gas. If both the primary and secondary balloons fail, heated CO₂ can be used as a much weaker and unstable lifting gas, this is rarely needed and cheaper drones can't.

Since cloud cities drift quickly on the winds, a balloon-lifted drone will return far away from its host city. This means cities must cooperate to maintain radio contact with probes, and returning drones have to be picked up by shuttle.

Tethers don't reach

Tethers are superior for short dips, down to 5 to 10 km under the city in calm weather. There is a constant risk of wind tearing the tether, and weather changes can spell disaster at any time.

Rockets are impractical

Fusion rockets built for Venus work very well; the atmosphere provides unlimited reaction mass. The problem is the pressure, heat, and weight: a vehicle sufficiently shielded to deep-dive in the atmosphere is so heavy few cloud cities can carry it, you would have to launch form orbit, which imposes further demands on the construction in a vicious circle.

Surface installations

There used to be scientific installations on the surface, even a small scientific habit in natural caves. None of these survived the isolation of the Fall and very little has been rebuilt, tough there are plans to do so.

Culture

Venus' culture is easygoing and open. The combination of small-town familiarity and chance-meeting when cloud cities dock creates a culture where people are secure in their home — Campanilismo and all that — and also comfortable with meeting one other similar homogenous community at a time.

This creates a rural feel to the cloud cities, where everyone knows someone who knows that guy and societal control is tight. Some feel confined by this and emigrate, either off-world or to a city more to their taste; like everywhere in the solar system, like pulls like to create settlements focused around a particular interest.

Leisure activities

The great leisure activity on Venus is hang-gliding, parachuting, and sailplane gliding. Children from age five fearlessly launch themselves into thin air, adults glide to visit nearby cities, continuous weather reports show wind as well as up and downdrafts in enhanced reality. Accidents happen, but acid-safe skinsuits and breathers are standard, normal parachutes buy enough time for rescue by drone.

Orbital Cities

The usual spin habitats fill Venus' orbits. Anything heavy that can be done in orbit is, and these habitats are much larger than the cloud "cities" below. This is where heavy processing is done, anything requiring heavy machinery, turning raw materials from below into exportable feedstock for printers.

The number of habitats around Venus cannot compare to those in cislunar or Jovian space, there simply is not enough business on Venus. Long-ranging terraforming is a dream and constant petitions are made to the Earthforce Commons, this is seen as the project that would finally get the Venusian economy rolling.

Surface Communication

Orbital and cloud cities can't pace each other , meaning that orbitals must cooperate to stay in touch with their allies below. A shuttle can easily dock at a habitat in any position, the problem is to stay in touch. Space habs forward messages, then try to find a high-altitude sky city with an open line of sight for a microwave link, who can then send the message by radio through a web of linked cloud cities.

Economy

The Venusian economy, and thus it's politics, is shaped by the randomness of storms. A cloud-city cannot be sure where it will be in a few days, and location can open new opportunities and alliances. This makes the economy very dynamic, but prevents true economy of scale.

Exports

Carbon — By tonnage, Venus’s flagship export is solid carbon from high-temperature CO₂ electrolysis, which also produces large amounts of O₂. Solid stock drags on buoyancy, so bulk is quickly shuttled to orbit for consolidation. The O₂ is either vented (benign), held as lift gas, or used as a clean thermal propellant for fusion rockets. Using O₂ as a chemical oxidizer is avoided and primarily seen as a fire hazard. This was exported directly after the Fall, but ice from the Belt is cheaper once you have a

Other Exports — Sulfur and sulfuric intermediates, nitrates, industrial gases, plastics precursors, and specialty reagents. All of these together amounts to much less than the carbon exports, and rides into orbit as a small extra load on the carbon shuttles. Some are shipped into orbit in half-refined form with the final processing done in orbit to avoid burdening the cloud cities with both the halfway material and the refining machinery.

Imports

Venus imports metals and minerals such as silica, primarily from Mercury, as well as water ice from the Belt. Intellectual property and services from Earth. Water can be extracted from compounds in Venus' atmosphere, but imports are cheaper once properly set up, and large quantities are needed to refine deuterium. Only a little of this water goes down into the atmosphere, most is processed in orbit with finished deuterium and polyethylene blocks for power generation.

The Membrane

Once native life on Venus was ruled out, humanity began adapting life to Venus. This came in the form of a membrane of lichen that forms floating layers in the atmosphere at 50 km altitude. Human supervision ceased with the Fall and it was expected they would die out, but they survived and even thrived.

Below several city-clusters, engineered biomembrane terraces have been regrown at the sharp inversion. These serve to separate the hostile lower athmosphere from the livable upper cloud layer. On top: near-Earth air and light foot traffic; below: hot, acidic, toxic chemistry farms. They serve as bioreactors, heat sinks, and emergency work decks — valuable, temperamental, occasionally predatory.

Adventure Seeds

1. Refinery blocs — City-states built around cracking stacks and acid plants; tariff-savvy, contract-heavy. Unusually large for a cloud city, such a refining city is stuck in a labor dispute and require mediation.
2. Skydock cartels — Control berths, tethers, and balloon traffic; arbitrate slot rights and weather fees. One polity has a long-standing contract in a port facility tat was just bought in a hostile takeover; help them claim their continuing right, undo the entire affair, or help to kick them out.
3. Cave Rescue — Radio emissions from the surface there might be Fall survivors in a cave on the surface, but drones can't enter fare enough into the caves make contact.
4. Solar Alchemy legacies — Pre-Fall exotic-materials lines are selectively restarted where feedstocks and buyers justify the risk. A manned expedition is needed, the first in many years. Requires low-altitude work, and the materials themselves disrupt radio drone control. Security checks require actual human touch on a security pad.
5. City on Overdrive — Platforms pinned in quasi-stable mesoscale lull cells or predictable shear minima; great throughput of something very valuable, sudden evacuations at abrupt drift/decay.
6. Surface launch window — A temporary inversion break or shear corridor that brings high-athmosphere conditions close to the surface, a window for a major descent. An entire city might be pulled down this funnel.
7. Derelict-no-more — “Ghost” cloud bases reoccupied but still half-mapped; old biotech and Solar Alchemy kit may be under new management, but the city does not communicate. This base had a policy of Neme-backups in a central quter, over the years the Neme information has merged into a general artificial intelligence. On boarding this appears to be a ghost town with only drones working, getting spookier and spookier until the cause is found. The AI wants to have humans that inhabitate the city but makes unreasonable demands and really seems to bant Neme information rather than actual people. Negotiate with this intelligence or blow it up to escape?
8. Mutated membranes — Parts of the biomembrane terraces have mutated, increasing in solidity and buoyance to the point that they can carry som topsoil made from previous generations of the membrane itself. This is a scientific wonder, but survivors, miscreants, organic dangers, and imminent collapse add danger.
9. Membrane ranges — Semi-solid terraces with smuggling niches, escaped strains, and corporate claim-jumpers.
10. Lower-atmo windows — Timed sorties to harvest rare fractions; lost pods, disputed salvage, and contract wars over ascent slots.
11. Hydrogen Heist — An H₂ balloon farm vanishes from a cluster at night—stolen lifting gas means cities lose altitude unless recovered fast..
12. VL2 Blackout: The Venus-L2 relay drops; line-of-sight laser chains must be hot-patched across drifting cities while rivals jam corridors.
13. Microwave Misalign: A high-alt power kite’s beam skews — brownouts cascade; ride the winds to re-aim reflectors before hospitals lose cooling.
14. Isotope Audit: A refinery’s carbon output shows non-terrestrial isotope ratios — smuggling, reactor scram, or an exotic feedstock find?
15. Acid Bloom: A new aerosol chemistry chews through standard skinsuits; recall/replace across a festival docking. Someone is responsible.
16. Union Line: Loaders strike; management hires off-world scabs. The local factory product kills the membrane. Keep perishable membranes alive while negotiating under drone pickets.
17. Balloon Tomb: A century-old Soviet probe is buoyed up by freak convection; grab the heritage core before it sinks or melts.
18. Glyder Derby: Annual zero-engine glider race between cities; sabotage, sponsorship bribes, and a storm wall moving in early.
19. Membrane Poachers: Corporate bioprospectors cut living sheets at night; track the skiff through wind lanes without ripping the local ecology. The membrane has clogged their drives, you now have to save the perpetrators.
20. DD Tether Scare: A D–D reactor gondola’s ballast winch jams; calculate safe altitude vs. radiation corridors and talk a panicking city through manual jettison.
21. Skydock Hostile: New owner voids legacy berths; prove lien chains through pre-Fall records scattered across three orbitals and a derelict.
22. Ozone Hole: A mesospheric chemistry shift spikes UV at certain hours; reroute traffic, retrofit envelope coatings, and find the culprit reaction.
23. Smuggled Lifter: Helium-3 declared as argon to dodge tariffs; a popped cell proves it. Who sent it? — trail the paperwork and the leakers. What are the receivers to use it for? — Its to be deposited in a storage to be claimed. Can you stake it out and catch the buyer?
24. AI Syndic: A cluster’s scheduling quter starts optimizing humans out; win back discretionary time or teach it to value festivals. What is the root cause of the fault — AI awakening?
25. CO₂ Fangline: A down-atmo extraction “drillship” is stuck in shear, tether fraying; stage a two-city rescue with crossing wind vectors.

Venus Descent Ops

Treat the surface like deep ocean. Keep mass and people at 55–60 km. Send down tethered work-pods or balloon-return pods; reel or float them back. Tether pod: winched from a cloud city; power/comms over the line; hours on task. Balloon return: drop a rugged pod; after work, inflate hot H₂ to ascend for pickup. CO₂ thermal lifter (rare): ingests CO₂, heats it indirectly, and jets it for VTOL — heavy, maintenance-hungry, hard to insure. Rules: Radio works below the clouds; use drones and a relay aerostat. No crews below; short sorties, redundant ascent, preplanned windows. If it can be done at 50–60 km, do it there.

See Also

• Venus 2315