ISRU Assessment Skill (In-Situ Resource Utilization)

Read CONVENTIONS.md at the repo root before proceeding.

This skill evaluates whether local resources at the destination (Moon, Mars, asteroids) can be extracted and processed to reduce launched mass from Earth. ISRU is the key enabler for sustainable beyond-Earth operations — every kilogram produced in-situ is a kilogram you don't launch.

Before You Begin

Ask the user (if not already known):

1. Destination body? (Moon, Mars, asteroid, other — determines available resources and environment)
2. Target product? (Oxygen, water, propellant LOX/LH2, metals, building materials, breathing air)
3. Required production rate? (kg/day or tonnes/year — drives plant sizing)
4. Resource characterization confidence? (Proven reserves vs. orbital remote sensing — huge uncertainty factor)
5. What design phase?

Applicable Phases

• Primary: Phase A (ISRU vs. Earth-supply trade), Phase B (process selection and plant sizing)
• Supporting: Phase C (detailed process engineering), Phase D (in-situ demonstration planning)

Resource Availability by Body

Moon

Resource	Source	Extraction Method	Confidence
Oxygen	Regolith (40-45% O by mass in oxides)	Hydrogen reduction, carbothermal, molten salt electrolysis	High (Apollo samples)
Water ice	Permanently shadowed craters (PSRs)	Excavation + sublimation/heating	Medium (LCROSS, M³, Chandrayaan)
Iron, Titanium	Ilmenite (FeTiO₃) in mare regolith	Beneficiation + reduction	High
Helium-3	Solar wind implanted in regolith	Heating to 700°C, very low concentration (~20 ppb)	Low economic viability
Silicon	Silicate minerals	Reduction (high energy)	High availability, low TRL for processing

Mars

Resource	Source	Extraction Method	Confidence
O₂ + CO	CO₂ atmosphere (95.3%)	MOXIE (solid oxide electrolysis): $2CO_2 \rightarrow 2CO + O_2$	High (demonstrated by Perseverance)
CH₄ + O₂	CO₂ + H₂O (subsurface ice)	Sabatier: $CO_2 + 4H_2 \rightarrow CH_4 + 2H_2O$ then electrolysis	Medium
Water	Subsurface ice, hydrated minerals	Excavation + heating, or microwave extraction	Medium-High (SHARAD radar)
Iron, aluminum	Regolith minerals	Thermite or electrolytic reduction	Low TRL

Asteroids

• C-type: 10-20% water, organics, clays
• S-type: Metals (Fe, Ni), silicates
• M-type: High metal content (Fe, Ni, possibly PGMs)
• Extraction in microgravity is a largely unsolved engineering problem.

Analysis Workflows

1. ISRU vs. Earth Supply Trade

The fundamental trade:

• Launched cost: $C_{launch} = m_{product} \times $/kg_{to_destination}$
  • Earth to Moon surface: ~$100k-500k/kg (current), ~$10k-50k/kg (target, Starship-class)
  • Earth to Mars surface: ~$500k-2M/kg (current estimates)
• ISRU cost: $C_{ISRU} = C_{plant} + C_{power} + C_{ops}$ amortized over production lifetime.
• Break-even: ISRU wins when $C_{ISRU}/m_{produced} < C_{launch}$ over mission lifetime.

2. Process Sizing

For each ISRU process:

• Feedstock rate: Mass of raw material per mass of product (stoichiometric + losses).
• Energy requirement: $E_{spec}$ (kWh/kg product) — this is usually the dominant constraint.
  • Lunar O₂ from ilmenite reduction: ~4-8 kWh/kg O₂
  • Mars MOXIE-class electrolysis: ~5-10 kWh/kg O₂
  • Water electrolysis: ~5 kWh/kg O₂ (plus ~0.6 kWh/kg H₂ co-product)
  • Sabatier: ~2 kWh/kg CH₄ (exothermic, but needs thermal management)
• Plant mass: Typically 50-200 kg per kg/day production rate (highly dependent on TRL).
• Ancillary systems: Excavation/collection, beneficiation, storage, distribution.

3. Power Requirements

ISRU is energy-intensive. Size the dedicated power supply:

• Solar: Available on lunar dayside (~1361 W/m²) and Mars (~589 W/m²). Not available during lunar night (14 days).
• Nuclear (Kilopower/fission): 1-10 kW per unit. Enables continuous operation, night-time processing, and PSR operations. Strongly recommended for any large-scale ISRU.
• Interface with power-assessment: ISRU power is additive to spacecraft/habitat loads — flag total demand.

4. Storage & Distribution

• Cryogenic storage: LOX, LH₂, LCH₄ — boil-off management is critical.
  • Zero Boil-Off (ZBO): Active cryo-coolers, ~15-20 W/kg stored per day.
  • Passive: MLI + low-conductivity supports. Boil-off rate 0.1-1%/day depending on scale and insulation.
• Gas storage: High-pressure composite tanks for O₂, N₂ breathing atmosphere.
• Propellant transfer: Pumped or pressure-fed transfer to vehicles. Interface definition needed.

Output Format

1. ISRU Feasibility Report (isru_report.md): Available resources, process selection, plant sizing, energy requirements, and break-even analysis.
2. Production Budget: Mass/energy/time per unit product.
3. Infrastructure Requirements: Power plant, excavation equipment, storage, and distribution.
4. 🟢 / 🟡 / 🔴 status: Feasibility and TRL assessment per process.

Interface

• Reads from: /requirements/, /analysis/mission-analysis-specialist/ (destination, surface conditions), /analysis/power-assessment/ (available power for ISRU), /analysis/propulsion-assessment/ (propellant demand)
• Writes to: /analysis/isru-assessment/
• Consumed by: propulsion-assessment (in-situ propellant availability), eclss-assessment (in-situ O₂/H₂O), cost-modeling (ISRU economics vs. launch), systems-engineering-assessment (infrastructure mass/power)