Preliminary Experimental Investigation of Multi-Shock Shield Performance Against Meteoritic and Other Lithic Projectiles

Abstract Introduction Micrometeoroid and orbital debris (MMOD) populations can vary significantly in composition, density, and homogeneity. Hypervelocity testing campaigns intended to optimize MMOD shielding are recognizing the need to launch impactors that span a range of densities, such as nylon, Al, Al2O3, steel, and copper, to capture the diverse extent of impactor densities [1 and 2]. These tests, however, pre-dominantly employ spherical and homogenous projectile materials. Adding composition-al/mineralogical complexity to the projectile, such as what could be expected from a micrometeoroid, will be concomitant with a more complex shock wave structure resulting from a hypervelocity impact, and will add uncertainty in estimations of the pressures needed to fully fragment, melt, or vaporize these impactors. Therefore, it is necessary to explore the performance of MMOD shields against more complex, natural projectile materials. To this end we have conducted a comparative test series to begin investigating the impact damage caused by meteoritic and terrestrial lithic analog (rock) projectiles, to that of spherical Al projectiles of similar mass.