Solar Sail Trajectory Design With Pulsed Radial Thrust

The solar sail thrust vector depends on the orientation of the sail nominal plane relative to the Sun-spacecraft line. In an ideal force model, when that plane is perpendicular (or parallel) to the Sun-spacecraft line, the thrust vector magnitude is maximum (or zero) and its direction is purely radial in a heliocentric reference frame. This Sun-facing configuration can be passively maintained through proper sail structure design. This correspondence analyzes the 2-D heliocentric trajectory of a solar sail in the case where the nominal plane can assume an orientation either perpendicular or parallel to the Sun-spacecraft line during flight. The novel contribution of this correspondence is to show that the polar form of the trajectory (which preserves the value of the semilatus rectum) can be obtained, as a function of the spacecraft angular position where the sail attitude maneuver occurs, using a formulation based on the combined use of linear systems analysis and regularization of the heliocentric equations of motion.