A5ES-ATV: Aerothermodynamical Study of the Deorbitation of the Ariane 5 Upper Composite

This paper is devoted to the methodology and techniques used by ASTRIUM-ST to analyze the aerothermodynamics of the A5 upper composite reentry. Direct Simulation Monte Carlo methods were applied to compute the composite's surrounding flows and thermal fluxes at walls for its different possible attitudes during deorbitation and along its various scenarios' flight paths. The results are then used as inputs for the determination of the composite's thermal behavior and especially of its main wall structures and equipments as well as propellant and helium tanks with the prediction of their rupture and the ejection velocity of their respective fragments.