Re-entry Aerodynamics and Aerothermodynamics Analyses of the Flying Test Bed USV-X in the Framework of a High Lift Return

The paper deals with the aerodynamic, aeroheating, and flight mechanics analysis of a reusable flying laboratory designed to perform a return from low Earth orbit at high aerodynamic efficiency with the aim to provide experimental data in the framework of reentry technologies. The flying test bed is a wing body with rather sharp leading edges and slender aerodynamic configuration. Several design approaches, ranging from engineeringbased to computational fluid dynamics analyses, have been addressed to assess the vehicle aero-thermal performance. To this end, aerodynamic results for a wide range of freestream flow conditions including reacting and non-reacting flow and different angles of attack have been provided and compared. Moreover, rarefaction effects on both vehicle aerodynamics and re-entry trajectory are also highlighted. Computational fluid dynamics results show that real gas effects seems to be negligible on the assessment of the concept aerodynamics; whereas flight mechanics analysis highlight that rarefaction effects, even though it has been shown that they strongly influence vehicle aerodynamics, do not significantly affect the concept return down to Earth.