Soil modeling for InSight's HP³-Mole: From highly accurate particle-based towards fast empirical models

Abstract

As a payload of NASA's discovery mission InSight, DLR's HP3-instrument is used to measure the internal heat ow of Mars. In order to reach the maximum penetration depth of 5m HP3's locomotion system, the self-impelling nail nicknamed "the Mole" will hammer itself into the martian subsurface. In order to improve, optimize and analyze the Mole's dynamic behaviour and its interaction with the soil several models were developed. In the article the enhanced multi-body model of the mechanism will be presented in combination with two soil models used during the mission's development phase. A highly precise particle model is used to analyze the dynamic interaction with the mechanism, as well as to enhance the simple but fast analytical soil model based on soil mechanics. Both techniques will be explained and the transfer of e�ects from detailed models to simple models will be shown.