Accurate Aerodynamic Model of Membranes in Free-Molecular Flow for Deorbit Device Design

This paper proposes an accurateaerodynamic model for membranestructures infree-molecularflow that allows the calculation of torque andforce exerted on them, and whichcan beused for preciseanalysisof the attitudes andorbital dynamics of the structures . Recently, various types of deployable thin membrane structures attached to satellites for deorbit purposeshavebeen developed and demonstrated on low-Earthorbits (LEOs), andtheir attitudedynamicshavealsobeen investigated. However, in early studies, deorbit sails were modeled as simple flat plates because there were no precise models for membranesthat could expresswrinkles, billowing, and asymmetricshapes.In this paper,a calculation method using tensor expressions of aerodynamic disturbance is proposed for the design of deorbit devices using high-fidelity membrane models. The proposed method is tested in the attitude stability analysis of membranes on LEOs, and the results show that the asymmetric shapes of the membranes affect their attitude stability.