Lunar Regolith Cement Mixer (LRCM) A Governed ISRU Construction-Material Processor for Lunar and Martian Surface Operations V10

Lunar Regolith Cement Mixer (LRCM): Governed ISRU Construction-Material Processor for Lunar and Martian Surface Operations Version: 13.0 Document ID: AEMS-LRCM-001 Author: Wayne Griffiths, AEMS LLC / Griffiths Canon Research Group Contact: wayne@aems.tech | ORCID: 0009-0009-4905-7909 Date: July 2026 Description Permanent habitation of the Moon and Mars requires structural construction material produced in situ. Importing Portland cement from Earth at launch costs exceeding USD 50,000 per kilogram is economically prohibitive for any structure beyond a small demonstration slab. Water-based hydration chemistry is unavailable on the lunar surface. There is no free water, no atmospheric moisture, and no pressure to retain it. A fundamentally different approach to construction material is required. This paper presents the Lunar Regolith Cement Mixer (LRCM), a governed ISRU processing vessel that converts raw regolith into structural construction material through four selectable binder pathways: sulfur concrete, alkali-activated geopolymer, water-ice cementation, and microwave sintering. The LRCM repurposes the Governed Electromagnetic Mixing and Batching Chamber (GEMBC) from the CSMMC methane-cracking architecture. The 316L stainless steel shell provides abrasion tolerance, thermal capability from ambient to 1,100 C, and vacuum-sealed integrity. Internal graphene capture coupons are replaced with mixing baffles and paddles. Residence-time logic maps directly to governed mixing time. A modular cartridge system allows pathway switching by swapping the internal cartridge assembly. A double-valve airlock enables regolith feed and product discharge without pressurising the processing volume. Four Binder Pathways on One Platform Cartridge A (Sulfur Concrete): The primary zero-import lunar pathway. Elemental sulfur extracted from regolith troilite at 600-800 C is melted and mixed with regolith aggregate at 130-140 C. The paper includes a full sulfur extraction mass balance quantifying upstream feedstock requirements. Extraction ratios range from 476:1 for pyroclastic deposits to 2,500:1 for low-sulfur mare basalt. The extraction furnace is the dominant Tier 3 power consumer. Spent regolith re-enters the LRCM as aggregate, closing the material loop. Version 13 adds a full treatment of sulfur vapor containment and post-cure sealing. A thin aluminosilicate film drawn from Cartridge B precursor chemistry is applied after cool-down to close the vapor escape path to vacuum. Sublimation suppression is treated as an unvalidated design provision pending Phase 1 vacuum-chamber mass-loss testing on sealed and unsealed coupons under simulated lunar thermal cycling. Cartridge B (Geopolymer): Alkali-activated aluminosilicate binder processed at 60-90 C under optional 0.5-2 bar overpressure. Compressive strengths exceeding 60 MPa. Requires imported or separately processed alkali activator. Cartridge C (Water-Ice Cement): Cryogenic freeze-bonding at -60 to -20 C using ISRU-derived water-ice. Viable only at permanently shadowed regions. Compressive strengths 10-25 MPa. Cartridge D (Microwave Sintering): Binderless ceramic blocks at 800-1,100 C using a 2.45 GHz magnetron. The paper expands the dielectric-loss tangent analysis. Iron- and titanium-rich mare basalts couple efficiently at ambient temperature. Highland anorthosite requires a governed resistive pre-heat step before magnetron start. For Mars operations, perchlorate decomposition releases chlorine-based gases requiring a corrosion-resistant liner or active gas scrubbing. Governance and Power Architecture All LRCM process parameters are governed under DIGSP using the Griffiths Equation. The governance kernel is a bounded-variable PID with hard safety limits. Any governed variable breaching its envelope triggers immediate safe-state reversion with heaters off, motor stopped, and valves closed. Version 13 expands the governance section with full variable envelopes for mixing temperature, agitator speed, vessel pressure, extraction furnace temperature, feed rate, and sulfur vapor partial pressure. Power is supplied through the GESH three-tier architecture: Tier 1 for water-ice, Tier 2 for sulfur concrete and geopolymer, Tier 3 for microwave sintering and sulfur extraction. Surface and Subsurface Construction The architecture supports surface construction and TBM-integrated subsurface construction. Version 13 expands the thermal balance analysis at discharge, including governed formwork pre-heat and discharge-rate modulation to prevent cold-sink freeze shells. Thermal expansion mismatch at concrete-metal interfaces is addressed through free-standing or mechanically keyed designs. Modifier outgassing under sustained lunar vacuum and UV exposure is treated with an accelerated test protocol. The Atlas governed robotic arm provides regolith acquisition, mould positioning, and product placement. Its 3.5 m reach covers a single-station construction cell. DIGSP governance shared between arm and mixer makes coordination a task-sequencing problem within a unified domain. Structural Performance and Falsifiable Predictions Version 13 expands the structural-performance envelope and simulation suite. Compressive strengths are presented for all four pathways. Thermal cycling endurance data and modifier stability analysis are included. Eleven falsifiable predictions define pass or fail criteria for prototype validation, including sulfur concrete strength, magnetic drive torque, airlock leak rate, reduced-gravity mixing, cartridge swap time, sintering power, DIGSP autonomy, geopolymer strength, sulfur extraction yield, thermal cycling endurance, and modifier outgassing. Path to Prototype A three-phase development programme takes the LRCM from GEMBC-spec vessel build through all-pathway validation to parabolic flight and thermal-vacuum testing. Version 13 adds sulfur vapor containment testing, dielectric-loss tangent survey, and sealed versus unsealed coupon sublimation trials.