Totally agree, a no-brainer for long missions:
For Starship’s large interior volume and long-duration missions (e.g., to Mars), plants offer food production, air/water recycling, CO₂ scrubbing, oxygen generation, and major psychological benefits through biophilic design—lush greenery combats isolation and stress.
Zero-gravity constraints rule out traditional soil (messy, heavy, and prone to floating particles). Instead, focus on hydroponics (nutrient-rich water solutions) and especially aeroponics (roots misted with nutrient solution in air), which have been successfully tested on the ISS via systems like Veggie, Advanced Plant Habitat (APH), and Sierra Space’s XROOTS experiment. These use minimal water, enable exposed roots that grow freely in all directions in micro-g, and scale well.
Fast-growing, compact crops thrive in controlled LED lighting (red/blue spectra optimized for space, often with green for natural appearance):
Leafy greens and salads: Red romaine/Outredgeous lettuce, Waldmann’s green lettuce, red Russian kale, mizuna mustard, Chinese cabbage/Tokyo bekana, Swiss chard. Quick harvests (weeks), high yield, nutrient-dense, excellent for fresh eating and morale. Grown in Veggie “plant pillows” (clay-based media) or aeroponic setups.
Herbs: Basil, mint, cilantro (common in Earth hydroponics; logical extensions from ISS greens). Provide aroma, flavor variety, and sensory stimulation.
Fruiting crops: Chili peppers (already harvested and eaten on ISS), dwarf strawberries, miniaturized tomatoes or peppers. Bio-engineered compact varieties with high harvest index (more edible parts, less waste) and parthenocarpy (fruit without pollination) are ideal.
Others: Radishes (fast roots), dwarf wheat (for grains/carbs in APH), and nitrogen-fixing legumes (beans/peas) paired with symbiotic microbes for natural fertilizer.
For lush, non-edible greenery that “feeds off air” and humidity:
Epiphytes / air plants (e.g., Tillandsia species, some bromeliads, orchids, ferns). These absorb water/nutrients directly through leaf trichomes (tiny scales) from humid air—no soil or constant watering needed. In Starship’s controlled humidity, they’d require only occasional misting. Secure them on mounts, driftwood, or structures; they won’t need pots. Excellent for air purification and visual interest without heavy systems.
Moss walls or low-light tolerant species (some ferns) for living panels.
Genetic engineering and selective breeding (via CRISPR and spaceflight data from GeneLab) can optimize for space:
Low-lignin plants: Easier to digest, better nutrient absorption for crew, and simpler waste composting/recycling. NASA is already testing these concepts.
Compact, high-yield varieties: Miniaturized tomatoes, dwarf fruit trees, or greens with faster cycles, higher photosynthesis efficiency, radiation/oxidative stress resistance, and altered growth responses to micro-g.
Biofortified or functional plants: Antioxidant-rich berries/tomatoes for radiation protection; nitrogen-fixers; or transgenic lines producing pharmaceuticals, bioplastics, or extra oxygen. Epigenetic adaptations from multi-generation space growth could be selected for hardier offspring.
Creative twists: Bioluminescent moss/plants (engineered for soft ambient lighting, reducing electrical load). Or vines/climbers trained into tubular or structural forms.
Starship’s volume allows artistic integration beyond ISS-scale chambers:
Aeroponic tubular towers/columns: Vertical or curved “tubes” (stackable modular sections) with internal misting. Plants grow outward in a living cylinder—use as room dividers, railings, or decorative pillars. Roots thrive in the aerated interior mist; scalable like commercial Tower Garden systems but space-optimized.
Wall/ceiling vertical gardens: Hydro/aeroponic panels lining bulkheads for immersive greenery. Combine with LEDs for glowing walls.
Floating or suspended epiphyte gardens: Secured air plants in artistic clusters or “zero-g mobiles” that appear to float (tethered for safety).
Hybrid biophilic habitats: Integrate plants into furniture, lighting fixtures, or partitions. Think living archways or tubular vine tunnels using climbing species. Concepts from biophilic design research emphasize this for crew well-being.
Key advantages in Starship: Ample volume/power compared to ISS allows larger Astro Garden-style systems for a crew of 4 (fresh salads decor). Plants recycle water via transpiration and integrate with ECLSS (Environmental Control and Life Support Systems).
Use plants to absorb and recycle human waste (urine, feces) and cooking waste (food scraps, gray water from sinks/cleaning) is a foundational concept in bioregenerative life support systems (BLSS/CELSS). These systems close the loop for air, water, and nutrients, turning "waste" into resources for food, oxygen, and clean water—exactly what long-duration Starship missions need.
Urine: Nutrient-rich (high in nitrogen, phosphorus, potassium) but salty. Processed via nitrification (microbes convert urea/ammonium to nitrates) or direct feeding after dilution/salt management.
Feces cooking/plant waste: Anaerobic/thermophilic digestion or composting (microbial bioreactors break down organics into bioavailable nutrients, CO₂, and water). Pathogens are controlled with heat, irradiation, or bacteriophages.
Gray water (from cooking, hygiene): Filtered and fed into the nutrient stream.