Experimental Application of a Catalytic Heat Flux Probe in Venus Aerobraking and High-Altitude Earth Re-entry Environments

Abstract

To investigate material behavior during Venusian aerobraking, a ground test facility is required that provides relatively low convective heat fluxes in combination with significant atomic oxygen fluxes. This study investigates the application of a PHLUX-type catalytic plasma probe to characterize such an environment in an inductively driven plasma wind tunnel. Using material specific properties regarding heterogeneous catalysis of oxygen recombination, the atomic oxygen flux in a highly dissociated plasma flow can be determined. For this study, copper and silicon carbide samples are utilized in the plasma probe. To determine the incident heat flux in the fringe of the plasma plume, the sample temperature is measured with both thermocouples and a thermal imaging camera. In the plasma wind tunnel PWK3 at the Institute of Space Systems (IRS) of the University of Stuttgart, atomic oxygen fluxes ranging from 1.0 × 10¹⁸ cm⁻² s⁻¹ to 1.5 × 10¹⁸ cm⁻² s⁻¹ are determined under convective heat fluxes up to 6.0kWm⁻². A brief overview of the application of PHLUX sensors as flight instrumentation for atmospheric entry studies is given with an outlook to future in-situmeasurements during the early re-entry stage of the SOURCE CubeSat.