Advanced Thermal Management for ISRU (In-Situ Resource Utilization) Additive Manufacturing
Manufacturing
Advanced Thermal Management for ISRU (In-Situ Resource Utilization) Additive Manufacturing (MFS-TOPS-137)
Thermal control process enables direct fabrication of high-strength structural components from raw lunar regolith
Overview
Establishing sustainable lunar infrastructure requires the ability to manufacture structural components using local resources. However, existing laser-based additive manufacturing approaches for regolith face significant challenges. The complex mixture of ceramics, metals, metal oxides, and minerals that constitute regolith causes each constituent to undergo independent phase transitions during laser processing. Current methods require energy-intensive pre-processing steps such as sieving, material distillation, or ball milling to achieve uniform particle distributions. Many approaches also depend on chemical binders or additives, which must be transported from Earth. These limitations make existing regolith AM techniques impractical for sustained surface operations.
In response to these challenges, researchers at NASA's Marshall Space Flight Center developed Additive Manufacturing of Glass-Ceramics from Regolith. The methodology uses precisely controlled heating and cooling rates, coordinated scan patterns, and strategic dwell times to manage the sequential phases of vitrification, Transforming raw regolith into fully dense, high-strength structural components without additives or pre-processing. The process produces glass and glass ceramic parts with compressive strengths exceeding 17,000 psi that enable direct fabrication of habitats, landing pads, and mission-critical infrastructure from in-situ materials.
The Technology
Lunar regolith presents unique challenges for laser-based additive manufacturing. Unlike conventional metal or ceramic powders, regolith is a heterogeneous mixture of ceramics, metals, metal oxides, and minerals. During laser processing, each constituent undergoes independent phase transitions, creating material behavior variations between layers. Excessive heat causes dissociation and gas bubble formation, while rapid cooling traps porosity. The glassy components are particularly sensitive; once melted, they cannot return to their original state, and improper thermal management during re-melting causes crystalline structure failures and anisotropy throughout parts.
This methodology addresses these challenges through coordinated thermal control across the build. Custom scan patterns and beam-shaping optics maintain target temperature ranges across the processing area while controlling heating and cooling rates. Layer height, hatch spacing, scan pattern, re-heating intervals, laser power, and inter-layer dwell times are precisely coordinated to manage the sequential phases of melting, nucleation, grain growth, and annealing. Previous layers of unsintered regolith act as insulation and as a controlled quench medium, maintaining temperature and preheating subsequent layers.
A dedicated build plate is not required; a firebrick build plate has been used to support rapid, quick-turn parameter development in a laboratory setting. Real-time thermal imaging monitors the process. The methodology has been demonstrated in sustained operation within a thermal vacuum chamber at 10e-6 Torr, replicating the operational environments for lunar and Martian surface manufacturing. The amorphous vitrified glass process is at TRL 5; glass-ceramic components are currently undergoing validation for final strength claims. This advanced thermal management process is available for patent licensing.
Benefits
- High Structural Performance: Produces fully dense glass and glass ceramic components with compressive strengths exceeding 17,000 psi.
- No Pre- or Post-Processing Required: Directly processes raw regolith without sieving, distillation, compaction, binders, or finishing operations.
- Machine-Agnostic Process: Demonstrated on both laser powder bed fusion and laser directed energy deposition systems, using traditional and beam-shaping lasers; not dependent on any specific vendor or platform.
- Controlled Crystallization: Manages the full vitrification sequence to produce crack-free glass-ceramic components and engineered fracture behavior, addressing the brittleness and anisotropy that limit conventional regolith AM.
- Multi-Environment Adaptability: Demonstrated with lunar highlands (LHS-1) and Martian (MGS-1) regolith simulants, with input parameters that fall within the range of conventional AM systems.
Applications
- Lunar Infrastructure: Construct habitats, landing pads, radiation shielding, and roadways for Artemis and subsequent missions using in-situ regolith.
- Mars Surface Operations: Manufacture mission-critical components, shelters, and infrastructure on Mars using locally sourced Martian regolith.
- Surface Outposts and Fuel Depots: Produce structural components, storage facilities, and protective barriers at lunar stations and deep space facilities.
- In-Situ Repair and Fabrication: Enable on-demand fabrication of AM materials during long-duration missions.
- Commercial Lunar Development: Support private sector infrastructure development for lunar mining, research facilities, and commercial operations.
Technology Details
Manufacturing
MFS-TOPS-137
MFS-34987-1
Patent Pending
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Similar Results
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The related patent is now available to license. Please note that NASA does not manufacturer products itself for commercial sale.
Waverider
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An agitator is secured to the drive shaft, facilitating the consistent movement and mixing of the regolith-polymer mixture in the hopper. The nozzle includes a tube with an open end and an occluded end, allowing the mixture to be extruded through the lower aperture.
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Recyclable Feedstocks for Additive Manufacturing
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Additive Manufacturing Model-based Process Metrics (AM-PM)
Modeling additive manufacturing processes can be difficult due to the scale difference between the active processing point (e.g., a sub-millimeter melt pool) and the part itself. Typically, the tools used to model these processes are either too computationally intensive (due to high physical fidelity or inefficient computations) or are focused solely on either the microscale (e.g., microstructure) or macroscale (e.g., cracks). These pitfalls make the tools unsuitable for fast and efficient evaluations of additive manufacturing build files and parts.
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The AM-PM method is at technology readiness level (TRL) 6 (system/subsystem model or prototype demonstration in a relevant environment) and is available for patent licensing.
