Solar Sail Trajectory Optimization for Asteroid Flyby and Rendezvous

Solar system exploration has emerged as a primary focus in the space community, with deep-space CubeSats standing out as a promising solution for studying asteroids within the solar system. This paper specifically addresses missions employing solar sail technology, aiming to explore the attainable reachability of a miniaturized solar sail departing from Earth. This is achieved by considering both flyby and rendezvous missions. Drawing inspiration from previous research using low-thrust propulsion, this work focuses on time-optimal missions, applying optimal control theory to achieve reasonable transfer times. The formulation relies on continuous guidance control, employing an indirect method derived from Euler–Lagrange variational equations and Pontryagin’s minimum principle. Results show that the algorithm is a versatile tool for obtaining optimal solutions for missions involving trajectories with multiple flybys.