Space-Debris-Detektion zur Validierung von Simulations-Modellen

Abstract

Space missions are affected by impacts of Space Debris (SD) and Micrometeoroids (MM). The amount of SD objects in orbit is increasing due to the past and present space activities. In contrast to SD, the MM environment can be assumed to be constant. Due to high relative velocities, collisions of spacecraft in orbit with SD or MM can lead to payload degradation, anomalies as well as failures in spacecraft operation, or even loss of mission. The risk assessment of SD and MM impacts can be performed by using environmental models such as MASTER (Meteoroid and Space Debris Terrestrial Environment Reference; ESA) and ORDEM (Orbital Debris Engineering Model; NASA). The result of these analyses is a statistical number of impacts on a given surface. Validation of the analytical models is essential to furthering model reliability and can be conducted by fitting the simulated results with measured data. Currently as most of the objects are too small for ground-based observations (e.g. radar, optical), the only available data for model validation is based on retrieved hardware investigations e.g. LDEF, HST, EuReCa. Since existing data sets are insufficient, further in-situ experimental investigation of the SD population is required. The aim of the present work is to provide a new solution for a large-scale impact detector, permitting the detection of SD and MM within a diameter range of 100 µm < dp < 1 cm. In the context of this work, the development of a novel in-situ detection method is undertaken. This work involves the design, the manufacture and the experimental testing of an innovative detector. The design of the detector considers the damage equations of ESA. Detector fabrication is performed in conjunction with four manufacturers and incorporates state-of-the-art elements and manufacturing technologies. The ground verification of the detection method is performed at the Fraunhofer-Institut für Kurzzeitdynamik, Ernst-Mach-Institut, EMI. The test results demonstrate that the developed detection method can be applied to SD and MM objects within the diameter range of 70 µm < dp < 1 cm. In-situ impact detection of objects e.g. >100 µm can be performed by using small satellites e.g. TechnoSat of the Technical University of Berlin. As object quantity as thus detection probability decreases with increasing object diameter, the detection of objects with larger diameters in the range of mm-cm requires a very large detection area or a multi-satellite constellation. A possible option to realize such a very large detection area may be provided by the Gossamer satellite, which is currently under development at DLR.