This page records the candidate space as it stood before the adversarial pass — every way of feeding a habitat that made it to the table, each stated with the assumptions it rode in on. Nothing here is ratified by being listed; several entries are dead, and the verdicts live on the analysis page. The point of keeping the full roster is the usual one: so the alternatives stop being re-derived, and so the reasoning behind what shipped stays legible.
Each entry: the mechanism, the initial appeal, and — flagged in advance wherever possible — what it quietly assumes. The assumptions are the attack surface.
Inside the habitat#
S1 — Open-field row cropping under the sky#
Terrestrial agriculture transplanted: fields of grain and vegetables on the main level, worked by machine, lit by the holographic sky. The default mental image, and the one the phrase “agricultural zones” invites. Assumes: land is the input to economize; the sky’s light is free and crop-suitable; a field behaves in a habitat the way it behaves on a planet; pest pressure arrives on planetary timescales.
S2 — Amenity / landscape agriculture#
Orchards, vineyards, paddies, olive terraces, market gardens, grazed meadow — productive forms of parkland the interior wants anyway. Food as a by-product of landscape, priced as such. Assumes: the interior will carry large designed landscapes regardless (canon: it does); polycultural patch layouts can hold their own ecologically inside the biome; somebody willingly does the labor.
S3 — Stacked controlled-environment decks (“vertical farming”)#
Sealed, lamp-lit, stacked hydroponic/aeroponic trays in decked volumes; tuned spectra, enriched CO₂, full automation. The terrestrial concept that never penciled out on Earth because electricity was priced. Assumes: the habitat can afford the lamp power thermally; deck volume is cheap (canon: it is, spectacularly); containment can actually be maintained at industrial scale.
S4 — Supplemented greenhouse strips on the main level#
A hybrid of S1 and S3: glazed strips on open ground, sky light plus supplemental lamps. Assumes: main-level ground is worth spending on production — i.e., that the land inversion (C3) is smaller than it is.
S5 — Open-water aquaculture#
Fish production in the habitat’s own lakes and streams, terrestrial-fishery style. Assumes: the water bodies can carry a production-scale nutrient load. Canon (C5) already looked hostile to this at listing time.
S6 — Recirculating aquaculture (RAS) and aquaponics#
Closed tank loops with their own filtration, coupled to plant beds. Assumes: a feed supply chain exists (fish are converters, not producers); containment discipline holds.
S7 — Conventional livestock#
The terrestrial ladder: poultry, pigs, dairy and beef cattle, sheep. Assumes: feed conversion losses are affordable (they multiply the whole upstream photon/land chain); a shared airshed tolerates epidemic reservoirs, odor plumes, and methane; slaughter at scale is culturally sustainable in a sealed world where nothing stays out of sight.
S8 — Insect farming#
Rearing on crop residue and food waste; output mostly as feed for fish and poultry, partly as direct food. Assumes: residue streams are collectable and clean; escape containment is manageable; direct-consumption acceptance varies and doesn’t need to be assumed at all if the role is feed.
S9 — Fungiculture#
Mushrooms and mycoprotein on residue substrates in dark volumes; spent substrate to soil. Zero photons. Assumes: enough residue exists — fungiculture’s scale is set by everyone else’s waste.
S10 — Algal photobioreactors#
Spirulina/chlorella in lit tube reactors; the classic space-colony staple of the literature. Assumes: algae’s photon-to-food efficiency advantage over crops survives contact with (a) whole-diet palatability and (b) the fact that lamp photons cost the same regardless of what absorbs them.
S11 — Single-cell protein on chemical substrates#
Hydrogen- or methanol-fed bacterial biomass (hydrogenotrophs, methylotrophs) in sealed dark reactors; processed flours. Electricity-to-food at several times any photosynthetic route. Assumes: nucleic-acid processing (the old gout problem) is solved (it is, and was by the twentieth century); acceptance as an ingredient rather than a dish; engineered-strain escape is containable.
S12 — Precision fermentation and cultured meat#
Microbially expressed milk/egg proteins; bioreactor-grown muscle and fat. Assumes: sterile industrial biotech at municipal scale; feedstock from S3/S11/S13; quality that clears the everyday bar even if it never clears the top one.
S13 — Cell-free carbohydrate synthesis#
Enzymatic starch/sugar from CO₂ and H₂ — demonstrated terrestrially at bench scale in the 2020s, here extrapolated to commodity scale. The photon-free bulk calorie. Assumes: the extrapolation itself (flagged: this is the roster’s largest single technology bet); product acceptance as ingredient.
Outside the habitat#
S14 — Agricultural free-flyers#
Uncrewed spun drums flying dedicated greenhouse volume on raw or mirror-concentrated sunlight; low pressure, robot-tended, orbiting near the habitats they feed. Assumes: nitrogen economics actually favor them (needs checking against C8, not assuming); crops tolerate low pressure and modest spin gravity; robotic horticulture is mature (canon automation makes this safe); solar-storm and radiation exposure is manageable for crops and seed stock; the dependence they create is politically survivable — which, after the scoop attacks, reads as: the fleet is a distributed soft target and everybody knows it.
S15 — Dedicated agricultural gyrealms#
Whole habitats specialized as farms — the “breadbasket habitat,” with resident farming populations and open-sky fields at scale. Assumes: a habitat’s defining cost (its nitrogen-filled sky) can be justified by producing the one commodity that specifically doesn’t need it. Flagged at listing time as suspicious.
S16 — Lunar and Mars surface agriculture#
Regolith-shielded, lava-tube or covered farms on planetary surfaces, exporting upward to the habitats. Assumes: the export leg — that lifting food off even a shallow well competes with free-flyers that start and finish in orbit.
S17 — Earth imports, bulk#
Earth’s recovering agricultural land as the breadbasket of the orbits; grain up the gondola. Assumes: lift energy per kilogram is small against food value — checkable against C9 in one line, listed for completeness because the political imagination keeps proposing it.
S18 — Earth imports, luxury#
Terroir goods only: wine, coffee, cacao, spice, aged cheese. Assumes: provenance carries price across a gravity well (safe: it carried price across oceans for all of history).
S19 — Chemotrophic and waste-heat exotics#
Radiotrophic fungi, thermophile chemosynthesis on industrial gradients, and similar literature curiosities. Assumes: yields matter at food scale. Listed to be killed in public.
Cross-cutting options#
- Atmosphere tailoring for crop volumes — hypobaric growing atmospheres (S3, S14) at a fraction of habitat pressure; possibly diluent-free. Assumes: C10 permits it (it does not permit the diluent-free version; see analysis).
- Sky seasonality as sanitation — running a cool short-day season partly as pest control (S2). Derived directly from the ecosystems page’s “altering the sky to disadvantage one producer” — listed as the one speculation that arrived pre-justified by canon.
- Reserve doctrine — deep dry stores + germplasm vaults + route diversity, as a system property rather than a technique. Assumes: storage is cheap in a habitat. (Terrestrial instinct says it isn’t; C3 says it is. The analysis page does the arithmetic.)