Articulating Hypervelocity Linear Accelerator Structure (Atlas) for Planetary Impact Science

Abstract

Abstract Hypervelocity impact cratering by asteroids and comets is one of the most common geological processes in the solar system. Investigations of the cratering process can be used to characterize the physical attributes of planetary surfaces and interiors, and to understand solar system evolution. Fundamental parameters including density, mass, and macro-porosity can dramatically affect a surface’s response to impact, consequently affecting the understanding of its evolution and history. Further, most natural impact events are oblique and can occur at a wide range of velocities, ranging from m/s for re-impacting crater ejecta, to 10s of km/s for asteroids and comets on terrestrial planets. As a result, laboratory experiments are a critical tool for investigating planetary impact cratering. Impact experiments can readily use rubble-pile and granular-media targets, which are difficult to model numerically, span a range of impact angles, and access hypervelocities. A new alternative design has been developed for conducting hypervelocity impact experiments for planetary impact science, using an Articulating hypervelociTy Linear Accelerator Structure (ATLAS). This design provides a concise solution for the investigation of a broader range of parameters on planetary bodies in hypervelocity impact research. Impact experiments require a relatively environment-free target chamber with little to no interference from combustion contaminants or sub-system gases associated with the accelerator. To address these needs, we present a combustionfree, two-stage light-gas-gun facility and articulating substructure that will be retrofitted to an existing linear singlestage accelerator housed at the Planetary Impact Laboratory at the Johns Hopkins University Applied Physics Laboratory [1].