Solar Radiation Pressure: Exact Analysis

Abstract

Moving beyond gravity-only dynamics about small bodies, we first consider the combined effect of solar radiation and solar tide perturbations on a spacecraft orbiting about an asteroid or comet. In this section we assume the central body can be modeled as a sphere, and neglect gravitational perturbations. This situation models orbital dynamics when far from asteroids or comets where the dominant perturbation will be from solar effects. We shall also see that for large enough bodies, such as Eros, solar radiation pressure only plays a minimal role. For missions to bodies whose sizes are on the order of a few kilometers or less, however, solar radiation pressure is the principal concern for orbital stability. It is interesting to note that the solar tide is generally negligible when compared to solar radiation pressure, yet it is included in this discussion for completeness. From a direct analysis of the equations of motion and their equilibrium points specific limits can be derived on orbit semi-major axis for when solar radiation can strip a spacecraft out of orbit. The analysis given here is based on some earlier work by Dankowicz [27] and the analysis given in [171].