Investigation and Trade-Off Study of Energy Dissipation oncepts for Small Body Landers Using Monte Carlo Methods

Abstract

This thesis investigates the residual kinetic energy of three energy dissipation mechanisms being applied to a small body lander shaped similarly to MASCOT. These three mechanisms comprise a gTanular damper, a crushable shell and Spikes. Additionally a probabilistic Monte Carlo-algorithm is applied to a program simulating the lander's movement sequence from the separation to the final landing for the lander in combination with the previously mentioned energy dissipation mechanisms and a randomly determined structure damping mechanism. Furthermore a sensitivity program analyses the relation of the input data which is defined by probability density functions to the outcoming variables of the lander's descent investigating program on which the Monte Carlo-algorithm was applied. The residual kinetic energy after the first impact relating to the granulate is independent on the impacting mass but on the ratio of the lander's and the granulate's mass. The energy which is dissipated at each irnpact effected by the mass ratio being 1 : 3 is defined by 1/3 of the impact energy. In every Scenario the crushable shell is thick enough to allow a dissipation of the total impact energy of the first landing. The Spikes dissipate on average 4 % of the impacting energy at each impact. The damping by MASCOT's structure, where the landing type dependent coefficents of restitution are defined by probability density functions dissipates 65 % of the impact energy at every impact.