Lunar Regolith Cement Mixer (LRCM) A Governed ISRU Construction-Material Processor for Lunar and Martian Surface Operations V10
Title: Lunar Regolith Cement Mixer (LRCM): A Governed ISRU Construction-Material Processor for Lunar and Martian Surface Operations Version: 10.0 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, the basis of all terrestrial concrete, 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 is not a clean-sheet design. It repurposes the Governed Electromagnetic Mixing and Batching Chamber (GEMBC), the thermal-gradient capture vessel from the Curvature-Stabilised Microwave Methane Cracker (CSMMC) plasma methane-cracking and graphene-production architecture. The GEMBC's 316L stainless steel shell provides the abrasion tolerance, thermal envelope (ambient to 1,100 C), and vacuum-sealed integrity required for regolith processing. Internal graphene capture coupons are replaced with mixing baffles and paddles; the vertical flow-path and residence-time control logic map directly to mixing time and curing preparation. A modular cartridge system allows pathway switching by swapping the internal cartridge assembly (estimated 8-20 kg per cartridge, single-crew EVA-handleable at lunar gravity), and a double-valve airlock enables regolith feed and product discharge without pressurising the processing volume. Four Binder Pathways on One Platform The LRCM supports four distinct cement pathways through interchangeable cartridges, each addressing different resource availability and mission constraints: Cartridge A (Sulfur Concrete): The primary zero-import lunar pathway. Elemental sulfur extracted from regolith troilite (FeS) at 500-800 C is melted and mixed with regolith aggregate at 130-140 C, setting by cooling to 30-50 MPa compressive strength. Requires no imported chemicals. The paper includes a full sulfur extraction mass balance quantifying the upstream feedstock requirements: extraction ratios range from 476:1 (pyroclastic deposits, 0.30 wt% S, 70% efficiency) to 2,500:1 (low-sulfur mare basalt, 0.08 wt% S, 50% efficiency), placing the extraction furnace in the Tier 3 power domain. Critically, sulfur-depleted spent regolith re-enters the LRCM as aggregate, closing the material loop.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. 10-25 MPa compressive strength.Cartridge D (Microwave Sintering): 2.45 GHz magnetron-driven binderless ceramic blocks at 800-1,100 C (CSMMC heritage). 20-40 MPa compressive strength. No binder, no imports. The paper addresses dielectric loss tangent dependence on regolith mineralogy: iron- and titanium-rich mare basalts couple efficiently at ambient temperature, while highland anorthosite requires a governed resistive pre-heat step before magnetron start. For Mars operations, perchlorate decomposition releases corrosive chlorine-based gases requiring a corrosion-resistant liner (Inconel 625 or Hastelloy C-276) or active gas scrubbing (calcium oxide bed). Governance and Power Architecture All LRCM process parameters are governed under the Distributed Intelligent Governance and Safety Protocol (DIGSP). The paper presents the Griffiths Equation as the bounded-variable governance kernel: a conventional PID control law with hard safety bounds on every governed variable (mixing temperature, agitator speed, vessel pressure, extraction furnace temperature, feed rate, sulfur vapour pressure). The distinguishing governance feature is not the PID kernel itself but the bounded-constraint enforcement and safe-state cascade it triggers: any single variable breaching its declared envelope causes immediate subsystem reversion to safe state (heaters off, motor stopped, valves closed) with no corrective-control attempt. Power is supplied through the GESH three-tier architecture: Tier 1 (RPPU-0) for water-ice, Tier 2 (GTRU) for sulfur concrete and geopolymer, Tier 3 (fission) for microwave sintering and the upstream sulfur extraction furnace. Surface and Subsurface Construction The architecture supports both surface construction (foundation plinths, equipment pads, landing surfaces, radiation shielding) and subsurface construction through integration with a tunnel boring machine (TBM). In the TBM-integrated configuration, the LRCM operates as the core of a closed-loop subsurface construction system: the TBM excavates regolith, an enclosed conveyor transports it to the LRCM processing module, sulfur or geopolymer binder is metered and mixed, and the resulting cement is discharged through a screw-conveyor placer to form continuous structural tunnel liners. The paper includes detailed analysis of thermal balance at discharge (cold-sink mitigation through governed formwork pre-heat), thermal expansion mismatch at concrete-metal interfaces (free-standing or mechanically keyed design, not adhesively bonded), and modifier outgassing under sustained lunar vacuum and UV exposure (DCPD and stearic acid long-term stability, with accelerated test protocol specified). The AEMS Atlas governed robotic arm provides the physical automation layer for surface construction. Its 3.5 m reach covers a single-station construction cell (extraction furnace, LRCM vessel, mould staging area), with GRFF wrist force sensing for regolith scoop control and mould placement, and a clip plate for rapid end-effector swaps. The arm shares the DIGSP governance protocol with the LRCM, making coordination a task-sequencing problem within a shared governance domain. Structural Performance and Falsifiable Predictions The paper presents compressive strength envelopes for all four pathways (sulfur concrete 30-50 MPa, geopolymer 40-65 MPa, water-ice 10-25 MPa, sintered regolith 20-40 MPa), thermal cycling endurance data (SIM-005: modified sulfur concrete vs unmodified over 500 cycles), and a simulation suite covering batch thermal profiles, power budgets, construction output scaling, and structural performance. Eleven falsifiable predictions (FP-1 through FP-11) define specific pass/fail criteria for prototype validation, including sulfur concrete compressive 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 under vacuum UV. Path to Prototype A three-phase development programme (USD 1.8-4.5M over 27-39 months) takes the LRCM from GEMBC-spec vessel build through all-pathway validation to parabolic flight and thermal-vacuum testing, producing TRL 5-6. Phase 1 includes modifier outgassing characterisation and regolith dielectric loss tangent survey. Phase 2 includes sulfur extraction trials with mass-balance verification and formwork pre-heat validation with sectioned interface void analysis. Phase 3 includes Atlas arm integration and TBM concept testing. Canon Integration The LRCM is not an isolated piece of hardware. It is a node in the Griffiths Canon autonomous surface-operations network, drawing directly on nine Canon systems: CSMMC/GEMBC (vessel heritage), CSMMC ICD (dimensional reference), GESH (power architecture), DIGSP (governance), Atlas Arm (positioning and regolith feed), MESSIAH (co-deployment), RFGC (thermal heritage), IDG-4/RPPU-0 (Tier 1 power), and IDG-5/GTRU (Tier 2 power). Three forward extensions are identified: regolith beneficiation via a GEMBC-hosted magnetic/electrostatic separation cartridge, in-situ modifier production from Martian atmospheric CO2 or lunar polar volatiles, and a fully automated DIGSP-governed construction cell integrating regolith acquisition, extraction, mixing, placement, and curing with no crew intervention.