Aerobraking and aerocapture - Aerodynamic and aerothermal study, applicability of inflatable structures

Abstract

A recent study performed by ESTEC and Lavochkin Association (Russia) on Venus and Mars Sample Return Missions has demonstrated that aerobraking allows great mass saving. It has been decided to investigate the further technological aspects associated with aerobraking and aerocapture. Therefore the aerodynamic aspects of spacecraft (SC) and descent modules (DM) at aerobraking and aerocapture regimes have been studied both theoretically and experimentally and are described in this paper.The useful effect of atmospheric aerobraking to assure the aerocapture and landing of massive modules onto planet surface during further expeditions is illustrated in this paper. The previous experience there has been mentioned as well.The study of aerothermodynamics of the SC at aerobraking regime along hypothetical trajectories shows that the modern calculating methods to determine the aerodynamic and thermodynarmc performances of the selected specific shape vehicles can give both accurate and approximate results.Calculations and experimental study of thermal protective system and thermal insulation (TPSTI) structures have been performed. These calculations include detailed analysis of rarefied gas flows, radiative and convective heat flux assessment.Plasma torch tests have been performed for various Multilayer Insulation (MLI) elements and for several materials, including ablative samples. Of a particular interest is a problem of thermal cycling and potential use of the new entry concepts (inflatable decelerators) has been addressed experimentally.As the result of these investigations, the regions of critical technologies are defined as well as the basic directions for theoretical and experimental study of the aerothermodynamics problems associated with SC aerobraking are recommended.