Fast Estimation Method for Trajectories to Near-Earth Asteroids

The paper presents a new approximate method for the estimation of minimum DeltaV and propellant consumption for electric propulsion missions to Near-Earth asteroids. The method is purely algebraic and therefore very fast, as integration of the equations of motion is not required. It is based on the decomposition of the propulsive effort into basic burns; each burn has a specific purpose (i.e., change of perihelion or aphelion distance). The effects and the cost of the basic burn arcs are evaluated for almost-circular orbits with small inclination changes. An approximate suboptimal control law, which was initially developed for continuous thrust maneuvers, is employed. In general, results show a very good accuracy, with errors below 10-15% of the propellant consumption. Larger errors occur for specific combinations of the orbital parameters, when the plane change maneuver does not follow the expected scenario. Suggestions for improvements of the estimation method are highlighted, as the analysis of the results gives insight about the characteristics of missions to different NEAs.