Silvio Schröder

Small penetrator probes have been proposed regularly as low(er) cost landing elements, particularly for network science. This study reviews such a concept with regard to its soil penetration capability with numerical and experimental investigations. A reference micro Mars lander (MML) is considered to deliver a 10 kg payload to the Martian surface. It decelerates the penetrator probe with a mechanical decelerator to 40–60 m/s before impact. The remaining kinetic energy is distributed to the soil and an internal load limiter on impact, which restricts the maximum g-load acting on the payload. A semi-empirical force–displacement law and a discrete element method simulation were used to describe penetration behavior. Major impact force constituents are the velocity-dependent, drag-like displacement of the soil particles and the compaction of soil along the penetration path. Based on the simulation results, a test penetrator was designed and tested by impacting it on different soil conditions with a maximum impact velocity of 10 m/s. Cohesive Mars soil simulant, non-cohesive quartz sand, and stones of various sizes were used to assess different impact conditions. The comparison of test and simulation data identifies their respective capabilities and limitations. Recommendations for use and findings for further research are deduced therefrom.

Small penetrator probes have been proposed regularly as low(er) cost landing elements particularly for network science. This study reviews such a concept with regard to its soil penetration capability with numerical and experimental investigations. A reference Micro Mars Lander (MML) is considered to deliver a 10 kg payload to the Martian surface. It decelerates the penetrator probe with a mechanical decelerator to 40–60 m/s before impact. The remaining kinetic energy is distributed to the soil and an internal load limiter on impact, which restricts the maximum g-load acting on the payload. A semi-empirical force-displacement law and a discrete element method simulation were used to describe penetration behavior. Major impact force constituents are the velocity-dependent, drag-like displacement of the soil particles and the compaction of soil along the penetration path. Based on the simulation results, a test penetrator was designed and tested by impacting it on different soil conditions with a maximum impact velocity of 10 m/s. Cohesive Mars soil simulant, non-cohesive quartz sand, and stones of various sizes were used to assess different impact conditions. The comparison of test and simulation data identifies their respective capabilities and limitations. Recommendations for use and findings for further research are deduced therefrom.

Prior to landing of reusable space transportation systems, the vehicle’s landing legs needs to be fully deployed to enable a safe landing and further re-use of the space vehicle. During that phase the deployment system has to overcome harsh and challenging environmental conditions. In this study, a numerical simulator is developed in order to investigate these influences on the landing leg deployment dynamics. By means of an extensive aerodynamic database and a broad approach flight domain, the influence of aerodynamics, exhaust plume, and vehicle’s attitude on the deployment dynamics is analyzed. This study shows on the example of the first stage demonstrator CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss back Operations), that thrust level, vehicle attitude, and the deployment system parameters affect the deployment performance.