Laser-Driven Cratering into Porous Graphite: Experimental Investigation on Ejecta Distribution

Abstract Introduction The sustainability of satellites is threatened by the growing number of space debris in low-Earth orbit [1]. Moreover, Earth is also at risk from the perpetual threat of collision with a celestial body. Understanding the behavior of rocky or porous materials similar to asteroids or comets, such as the crater formation and the debris distribution, is thus crucial for planetary science and for designing planetary defense missions. Indeed, deflecting asteroids requires an understanding of the contribution of ejecta to the momentum transferred during hypervelocity impact (HVI) [2] regarding the momentum enhancement [3]. To reproduce such impacts in laboratory, double-stage light gas-gun, High Explosive or laser-driven flyer methods can be used but are limited in terms of impact velocity and projectile sizes. This is why high-power pulsed lasers are employed to offers analogous effects to HVI in terms of crater [4] with significantly higher projectile velocities, shooting rate, with smaller dimensions than the constraints of launcher. Recently, an analogy between laser-driven cratering (LDC) and HVI was proposed [5] to determine an equivalent projectile that may reproduced the same crater volume on EDM3 target. Hence, the purpose of this work was to study the debris cloud from LDC experiments on porous graphite target to investigate the ejecta size and mass distributions, velocity and their contribution to the transferred momentum considering an equivalent projectile from the analogy between LDC and HVI proposed by Aubert et al. [5].