In Situ Lunar Launch and Landing Pad Construction with Regolith-Thermoset Polymer Composite Materials

Lunar launch and landing pads are necessary to mitigate risks to lander/ascent vehicles and surrounding surface assets from rocket plume ejected regolith. Significant risks exist for the larger landers proposed for the Artemis Program due to higher thrust levels leading to increased ejecta and cratering, presence of co-located assets in the ejecta path, and potential strict surface levelness requirements for tall vehicles. Regolith-thermoset polymer composite materials were developed and evaluated for off-Earth launch and landing pad applications. Performance under methane-oxygen rocket engine firing conditions was assessed for simulated Starship lunar launch/landing environments. Though significant erosion was experienced during some testing conditions, all test articles successfully mitigated regolith ejecta from plume effects. The mass of polymer required to be landed on the Moon constitutes a primary risk for the application of regolith-thermoset polymer composites as a lunar launch/landing pad. A Starship with planned 100 t payload capacity to the lunar surface could provide enough polymer mass for all but the largest pad sizes. A concept for preparing and emplacing the materials was developed and tested in laboratory conditions. The testing evaluated the feasibility of using screw extruder technology to mix, convey and deposit materials. Screw extruders were capable of processing and extruding the composite with a maximum of 90% mass fraction of regolith achieved. The feasibility of the regolith-thermoset polymer composite based construction approach was proven in three critical areas: performance under engine firing simulating launch/landing conditions, fitting within the planned lunar payload capacity, and demonstration of a mixing and depositing concept. The materials must be proven to be compatible with lunar environments. It is recommended that development continue to TRL 6 for a small-scale lunar demonstration.