Attitude maneuver design for planar space solar power satellites

Abstract

This paper investigates the attitude dynamics of a planar space solar power satellite (SSPS) by formulating the power-optimal guidance problem as a nonlinear trajectory optimization problem. The power-optimal guidance problem determines the orientation of an SSPS throughout its orbit that maximizes the amount of power transmitted to Earth. This transmitted power is a function of the relative geometry between the SSPS, the Sun, and the receiving station. Hence, it is inherently coupled to the attitude of the SSPS, i.e., the orientation that maximizes power transmission changes as the relative geometry changes. We first approximate the discretized trajectory optimization problem as a quadratic program (QP). We then solve the QP to obtain attitude trajectory designs for various orbits. These solutions highlight how maximizing transmitted power typically requires large slew maneuvers. Ultimately, by quantifying control and propellant requirements for various orbits, we emphasize how maneuver dynamics play an important role in SSPS design.