Novel Construction of Lunar Landing Pad Reinforcement Structures

Early Apollo-era landings encountered a variety of hazards including obstruction of visibility, high-velocity ejecta, and plume cratering. These problems resulted in damage to the lander and nearby equipment. Going forward, to safely conduct repeated landing and launch sequences on the lunar surface, landing pad designs will be required to mitigate plume effects, redirect and/or capture exhaust flow, and dissipate the kinetic energy of debris and ejecta. Prior efforts by the Linc-Lunar PAD team resulted in a successful subscale 610 cm diameter design that was 3-D printed and underwent hot fire testing with a M-class motor hot-fire test. However, this design relied heavily on overhang features that required water soluble internal supports that would not be feasible for lunar printing. During Phase 1 of this NASA STTR, the Linc team evaluated various conceptual designs and construction approaches for printing on the lunar surface. Based on prior work and anticipated infrastructure on the moon, a block like approach was selected where individual pieces could be assembled in the diameter required. Preliminary analysis of the conceptual design approaches combined structural integrity with plume mitigation. Based on the design features evaluated, key features were identified that were used to establish a preliminary block design. The Phase II efforts will advance the preliminary block design resulting from the Phase I efforts into a prototype that will be subjected to verification tests for evaluation of functionality. As a deliverable on the Phase II efforts, a 6 m diameter subscale landing pad will be delivered to the NASA-MSFC facility for their evaluation for hot fire testing evaluation in a vacuum environment. The Phase II effort will advance the technology from a TRL of 1 in Phase I to a TRL of 3.