Non-spherical dust dynamics of the plume evolution in support of the LICIACube mission

Among the main scientific objectives of the Light Italian Cubesat for Imaging of Asteroids (LICIACube) spacecraft, an Italian Space Agency space mission, the study of the plume ejecta evolution after the NASA Double Asteroid Redirection Test (DART) impact is of particular importance. We focus on investigating the dust dynamics of the plume evolution using numerical simulations of dust particles motion. The particles dynamics is governed by two main forces - gravity and solar radiation pressure. In our simulations the dust dynamical behavior was evaluated assuming initial velocity and torque of the particle after the DART impact. Based on a 3D+t non-spherical dust model that solves the Euler dynamical and kinetic equations and considering free-collisional dust regime we study the effects on the particle dynamics considering different shapes, initial particle orientation and velocities as well as torque. In addition, we performed dust simulations for different surface material cases considering the physical parameters of (65803) Didymos. The optical thickness of the plume varies not only due to the particles size distribution but also due to their shapes and orientations. Indeed, if a particle is characterized by an initial torque and hence rotate during the plume evolution then its velocity will be different than a non-rotating one with the same mass, shape and size. We are currently using a point source scaling model for initial setup of parameters. In this work we will shortly address at what distance particles could eventually stop to accelerate/decelerate as a result of the balance among the forces governing their motion. This study coupled with LICIACube plume images will further constrain the momentum transfer efficiency ?, in particular the local surface properties as strength, density and porosity as well as the ejecta velocity and size distribution.