Solarelastic Stability of the Heliogyro

Abstract

This article presents a methodology for analyzing the solarelastic stability of a solar sail spacecraft blade. This paper couples linear and non-linear rotating structural models with an optical solar radiation pressure model for a completely reflective surface. The resulting time varying ordinary differential equations are solved in a quasi-static sense, where an instantaneous stability boundary is determined. The quasi-static analysis with the linear model predicts a divergence type instability and slow and non-uniform modal convergence using parameters for a representative heliogyro spacecraft blade. The non-linear model predicts a flutter instability at a lower radiation pressure and has improved modal convergence characteristics. The paper uses the non-linear model to evaluate the stability of a NASA heliogyro concept design and explore the dependence of the stability boundary on the spacecraft rotation rate for the case of the sun directly overhead. Increasing the spin rate of the spacecraft improves the solarelastic stability, but must be traded off with decreased spacecraft maneuverability.