On the optimality of a shape-based approach based on pseudo-equinoctial elements

Pseudo-equinoctial elements have been developed to generate sub-optimal first-guess solutions for low-thrust transfer trajectories. In this paper we assess the optimality of such a simplified transcription technique and their suitability to initialize either direct collocation methods or indirect transcription methods. Two different shapes for the pseudo-equinoctial elements have been considered and the optimality of the resulting control profiles have been compared. Furthermore, a simple procedure to initialize an indirect method with the result provided by the pseudo-equinoctial elements is proposed.