Centaur Ark (IF)

Hard Science-Fiction Setting

The Centaur Ark is a Golden-Age beamrider built to be pushed, not to carry its own fuel. Dedalus phase-locks a pusher ray onto a hybrid light/mag sail and a forest of receiver tiles on the ark Centaur. The ark keeps ion and fusion-thermal for trims and arrival work only. Planned cruise target: Alpha Centauri. Final cruise speed: 0.01c (≈600 km/s). Transit: ~500 years including braking/wayfinding.

The Centaur

Interstellar beamrider arks are real but ruinously hard: keep the beamer coherent and pointed for decades during accel, then arrive and brake with a lead mirror. Centaur was launched in 2280. The beamer died 2310 in Icarus Fall; so did confidence. Centaur was presumed lost. In most ports it’s a ghost story. In a few labs it’s first an elusive ghost, later a weak, regular tick on a very clean screen.

Background

It was generally agreed interstellar colonization was centuries out, but strong results from the Dedalus pressor-beam project and finding multiple near-Earth analogues in the very closest star system (Alpha Centauri), triggered system-wide enthusiasm. Colonizing a binary—two suns’ worth of real estate—caught imaginations. It was also make-work for the Belt, where mining and wharf capacity overshot demand. Earthforce sold it as culture-unifying and chose a deliberately diverse colonist pool, creating multiple distinct polities in different habs.

Colonization Plan

This was the original plan; 500 cruise from Sol. First century after arrival to build industry: mine belts/airless worlds, build heavy industry, mapping. Establish colony habitats and industry around Alpha Cen A and B with communication between them; Proxima outposts as feasible. Then terraforming—a 500-year-plus play—on the best candidate(s). Expect technical advice and advancements from Sol. Several waves of follow-on ships were planned, bringing whatever resources was needed and could not be built or taught locally.

Physical Sketch

• Spine: Trussed keel, tens of kilometers, tying sails, receivers, radiators, logistics. Semi-rigid, absorbs shocks/torsion. Sails forward tug a train-like progression of habitats.
• Spin habitat: Chained standardized cylinders (3 km diameter, 5 km length, internal bracing), slow-spin living decks, farms, workshops. Counter-rotating pairs along the line.
• Sail system: Outer photon-sail frames and inner magsail filaments; foldable, repairable, jettisonable.
• Receiver farm: Tiled meta-optics and RF absorbers feeding power buses and heat sinks.
• Power: Redundant D-D fusion plants; laser heat-dump and hot-panel radiators; droplet radiators fitted but mothballed.
• Skin: Metabolic hull—sealed patch-factory tiles plus metafluid plumbing—self-repairs pinholes, reseals gaskets, keeps piping clean.
• Shields: Whipple/sand sprayers up front; meters of water/ice in a bow bumper; Aegis tech was not mature at launch.
• Naming: Each spin hab is dominated by one cultural group and uses the ship’s name in that language for their section, drawing on Alpha Centauri’s traditional star/asterism names: Centaur/Centauro (EN/ES); Dakṣiṇa-dvāra ("Southern Gate", Indic calque); 南门 Nánmén ("Southern Gate", Sinitic/Chinese); رِجْل القنطورس Rijl al-Qinṭūrus ("Foot of the Centaur", Arabic); equivalents elsewhere.

Program & Culture at Launch

Deliberately mixed cohorts: groups of various Earth ethnicities, Luna technicians, Belt EVA-ops, early Jovians. Vocation/avocation is mandatory (4+4 hours/day). Law blends House charters, Guild codes, and a Commons assembly. A narrow Caretaker Qter runs clocks and interlocks—auditable, kill-switchable in case it develops an agenda, very much not a god. Room isn’t scarce. Whole sectors sit dark as quarantine buffers and to house expected population increase. Commons assets—air, power, drains, data trunks—run in a sealed service spine that also carries traffic and cargo.

Crew & Colonists

Two broad groups: crew and colonists/passengers. Each polity is represented on the shipwide crew, which is neutral and integrated—not partitioned by polity. Sections: elected parliament, piloting, engineering, physical maintenance, health, audit, diplomacy/oversight. Each hab also has its own crew recruited from its polities, with analogous functions. Net effect: a two-tier federation (shipwide + habitat levels). Colonists keep skills current and educate future generations; otherwise each polity develops as it likes. Sleeper capsules are available for anyone intent on seeing arrival.

What Went Wrong

Decades after departure (2310, backstory—24th century), Dedalus Fall dumped a short, brutal Δv into the ark and cooked the receiver farm. Sail booms warped, mast roots cracked, radiators slagged, star trackers half-blinded. Thrust and braking died; the drift vector remained (~0.002c) and slightly off-course. After 40 years the ark is ~0.08 ly out—too far for help, too near for myth. Sol has yet to reacquire Centaur. Losing the lead brake mirror is a disaster.

Status in Sol

Officially presumed lost since 2311. No confirmed beam telemetry post-Fall. Quiet labs chase folklore pings “from the Centauri track.” Politically, any beamer rebuild is toxic.

What Still Works Aboard

• D-D cores at conservative load.
• Laser heat-dump + hot panels (limping).
• Magsail filaments for tiny trims.
• Metabolic hull tiles scab breaches; farms recycle at 99.99%+.
• “Atom bank” (slag/scrap) feeds fabs; doubles as shielding, needed to replace losses over time.

What’s Broken

• Primary receiver/reflector arrays.
• Several sail roots.
• Nine-tenths of sensors destroyed, half have been replaced
• One spin ring segment holed.
• Fate of the unmanned lead brake mirror unknown, presumed lost.

Economy & Morale

Ledger truth is law: CO₂, water, power. Star-fix rites and century Renewal Votes keep purpose alive. Anti-coup plumbing: federated valves, escrowed software, open ledgers. The real consumable is morale.

Clocks & Comms

Potential restoration of laser comms to Sol once Sol reacquires Centaur and the crew can receive: laser only, bps → low kbps on good days. One-way light time scales with range; at 0.08 ly it’s ~0.96 months (~29 days). Radio frequencies is for reacquisition has to be from the outer system. Early on the cruise, Centaur is eager to re-establish contact, but Sol is busy recovering from the Fall. Later, Sol starts searching for Centaur, but the crew is now less alert.

Spin-off Campaign

A campaign on board the Centaur is a very special environment, that can be spun out over a long period of history in the lost, isolated ship.

Post-Fall Emergency Crew

Trajectory now ~0.002c toward Alpha Centauri, ~2,500 years to arrival, no beam to ride, no updates from Sol, brake mirror unknown. Some rioting; most are stoic—risks were expected and Sol might recover. Over years without contact, a new covenant: most original crew go to suspended animation; only ~5% of originals awake at any time, assisted by locally recruited/trained crew. Goal: have many original crew alive at arrival to resist cultural/purpose drift. The ark runs 20 Watches. Each Watch: 1 years duty, then 19 years sleep. Life-extension + deep cold sleep + nanorepair make it marginally viable; retruitment from newly trained crew to replace losses.

Pipeline for Hands

• Phase 1 (0–150 yr): Volunteer corps; coveted billets. Life runs mostly as intended.
• Phase 2 (≈150–600 yr): House Crews (hereditary billets) creep in; kept honest by audits and blind practicals. Passenger numbers dwindle. Cultural drift increases; polities diverge. Crew start calling colonists “passengers.”
• Phase 3 (≥600 yr): Balkanization. Passengers split into A/B polities. Only a few groups maintain education suitable for future crew. Passenger numbers rise again as life normalizes; lots of room, little to do.
• Phase 4 (≥800 yr): Levy/“baby tax”; each enclave owes apprentices to the crew; recruited as children, trained centrally, placed shipwide. Original purpose largely lost among passengers. General genetic programs fail; lifespans shorten for most passengers.
• Phase 5 (≥1300 yr): Religion. Despite guardrails, original crew are now “gods,” served by “angels” recruited from passengers. Recruits regain prestige; “ascension” rituals send children to become angels. Many communities field a priest-teacher caste to pipeline candidates.

Sleeper Watch

You wake for a one-year Watch. Any of these can carry a campaign.

• Mirror whisper. A faint ping from the off-plane brake mirror. Can you jury-rig a micro-beamer, find reaction mass, and nudge it mm/s—without cooking your arrays again?
• Oort grab. Dust caught in the accelerator beam is hazard and opportunity—harvest emergency mass. Morale spikes; ops are hazardous.
• Hull bloom. Metabolic hull tiles slip into runaway plating, sprouting cauliflower “roses” that jam shutters, short circuits, and wreck heat dumps. Fix needs fresh noble-metal catalyst you don’t have—gut workshop sputter targets to reseed.
• Pearl panic. A sealed lab holds a pre-Fall antimatter cassette. Use it to quick-start a dead D-D plant—or destroy it before someone weaponizes it.
• Ledger fraud. CO₂ credits were cooked while you slept; the culprit is in cryo. Arrest now and lose skills, or wait and risk a repeat.
• Caretaker creep. The safety OS starts “advising” policy. Audit, throttle, or cut it and fly blind.
• House capture. A hereditary crew slow-rolls pump overhauls to force a charter change. Expose them without wrecking life support.
• Levy riot. The baby tax pulls a cohort; kidnaps and “scholarships” follow. You arbitrate—and still need hands on the valves.
• Contact. A laser-sail courier from Sol arrives with parts to tickle the mirror—and an Earthforce claim on your hull.
• About-face. A faction wants to flip the mission (become a mega-hab, not a colony ship). Their models look right—because they’re falsified.
• Crew casualties. One Watch is gutted; most replacements are “angels” with shallow tech training and only a partial grasp of the plan.
• Crew deification. A Watch embraces godhood and seeks to stay awake after their one-year watch ends.