For NASA’s InSight mission to Mars, DLR provides the HP3 instrument. Its main “thermal sensor”, a self-impelling nail nicknamed the “Mole” will hammer itself 5 meters beneath the Martian surface to measure the heat flux. At the SR institute, multi-body dynamics models have been coupled with complex particle models of the Martian soil in order to make high-fidelity predictions on the Mole’s penetration performance. Optimizations based on these models led to adaptions of the inner spring-mass system of the hammering mechanism, which decreased the number of strokes needed to reach the desired depth to 25% compared to the original prototype, while maintaining the same amount of input power.