Experimental and computational fluid dynamics studies of superorbital earth re-entry

A spacecraft returning to Earth requires an effective thermal protection system (TPS) to withstand the hypervelocity flow and extreme heat loads encountered during an aerobrak-ing descent. The potential to optimise TPS designs while ensuring a successful return depends on confidence in ground-based prediction methods, which can be achieved by verifying such methods with flight data. The infrared (IR) and ultraviolet (UV) spectroscopic data collected by University of Queensland researchers during the Hayabusa spacecraft re-entry has been the basis for numerical studies using the in-house compressible flow computational fluid dynamics (CFD) code eilmer3 and experimental studies in the X2 expansion tube. Numerical spectra generated from CFD simulations of the full scale vehicle at the selected trajectory point will be compared to experimental spectra captured from the binary scaled and enthalpy matched radiating shock layer around a Hayabusa model, and both sets of ground testing data will be compared to flight.