Thermal & Mechanical Performance of Lunar Simulant Bricks For Landing Pads: Glass vs. Crystalline

Advancing technologies for in situ resource utilization (ISRU) landing pad construction materials is critical to mitigate plume–surface interactions (PSIs) for future lunar missions, particularly as rocket power grows. Debate exists over which ISRU‑derived material is most suitable for lunar construction. We evaluated three candidate materials for lunar landing pads: (1) lunar plutonic crystalline analogs (Stillwater anorthosite, norite), (2) 1650°C molten-poured highland simulants (NUW-LHT-5M, OPRH4-W50), and (3) pressed and then furnace-sintered bricks of the same simulants. Mechanical performance was characterized via uniaxial compressive strength (UCS) using an Instron TS9 at 200lbs/s measured at 20hz following ASTM D4832. Split tensilestrength was assessed following ASTM C496. Thermal resistance was assessed using NASA MSFC’s Plasma Torch Testing Facility (PTTF) following a modified NASA standard EM40-OWI-013 blasting bricks at 2.5in standoff for 10s with an Ar-N mix. Heat flux was measured prior to verify BTU delivery before sample firing. Surface temps were measured with a Fluke Endurance® Series dual-band IR pyrometer and backside temps measured via thermocouple. Blasted samples were assessed for erosion depth via a Keyence 3D white-light scanner and weighed to asses mass loss.Glassy molten-poured bricks failed near ~50MPa in compression, however had low tensile resistance suffering brittle fracture under plasma exposure. In contrast, holocrystalline analogs exhibited superior compressive strength (e.g., Stillwater anorthosite = 116.4 MPa) and showed minimal damage after PTTF testing. Sintered bricks, despite >200°C variation in processing temperatures, displayed comparable thermal resistance. These findings suggest that crystalline and sintered materials are the most promising candidates for lunar landing pads. Moreover, effective thermal protection may be achievable through low-temperature sintering routes, offering practical pathways for ISRU construction. Future efforts will investigate how UCS varies with sintering temperature and time to further optimize high-T sintering of the simulants.