Speaker
Description
Understanding the processes of spacecraft break-up and demise during re-entry is essential for validating simulation tools, improve the design-for-demise philosophy and develop new approaches to reduce a potential environmental impact to the upper atmosphere. Ongoing efforts from the High Enthalpy Flow Diagnostics Group (HEFDiG) at the Institute of Space Systems at the University of Stuttgart are experimentally investigating all steps from break-up, demise and pollutant formation. Furthermore, HEFDiG collected a large number of airborne observation data to assess the real re-entry scenario.
A particular activity recently invented is the analysis of a large variety of spacecraft materials under thermochemical and aeromechanical loads under flight-to-ground duplication. This means that the aerothermal testing is extended by adding mechanical loads through a load cell.
Moreover, in addition to common structural spacecraft materials such as aluminum alloys, titanium and stainless-steel materials one recent activity focuses on a range of more exotic metals used in spacecraft. Round bar samples of Invar, copper beryllium alloy, titanium zirconium molybdenum, tungsten copper, and Inconel alloy 625 were tested. The samples were inserted in a supersonic plasma flow corresponding to LEO re-entry trajectories at 80 km altitude and the tensile loads were applied. The samples were observed visually, thermally and spectrally. The results highlight that mechanical loads can have a significant impact on the failure characteristics of the materials depending on the material in question.