Selection of design parameters for CubeSat 6U nanosatellites to ensure passive three-axis stabilization

This article studies design problems of CubeSat 6U nanosatellites (NS) to ensure a specified angular motion in low circular orbits. The classification of three-axis passive stabilization systems previously proposed for Cube Sat 1U-3U NS is extended to Cube Sat 6U NS, with due regard to specific features of this type of spacecraft. Altitude ranges have been identified for each type of passive stabilization determined by the dominant effect of a certain type of applied moment. Analytic expressions for distribution functions of maximum deviation angles of nanosatellite axes from the required directions have been obtained for the cases of uniform distribution and Rayleigh distribution of the components of the initial angular velocity vector. Formulas have been derived, and nomograms have been constructed for selecting CubeSat 6U design parameters (margin of static stability, moments of inertia) ensuring a required three-axis passive orientation with a given probability for typical cases - orientation of the longitudinal axis along the local vertical or along the forward flow vector.