Numerics of Discrete Element Simulations in Milli-g Environments: Challenges and Solutions

Abstract

As part of JAXA's MMX mission, a rover, jointly developed by DLR and CNES, will be deployed on Phobos [1]. Its task is to scout the landing site for the MMX spacecraft and to gain in-situ insights on the Phobos regolith. Major challenges to the mission's success are the extremely low gravity on Phobos and its mostly unknown regolith properties [2]. Effective gravity on Phobos ranges from 3.1×10 -4 m/s² to 6.8×10 -4 m/s² [1]. So far, no wheeled rover has ever been deployed under comparably low gravity. So, to ensure the mission's success, the rover wheels and their traction have been examined and optimized using DEM simulations (see Figure 1) [3].