Alternative approach to the DART mission by the use of gravity assist maneuvers with the Moon and solar sails

The formation of our Solar System and planetary defense strategies are among the priorities to be investigated in the next years by the space science community. As in-situ missions to small bodies (as comets and asteroids) are options to conduct these investigations, this paper proposes a combination of methodologies to produce low-cost transfers to near-earth asteroids (NEAs). Low-cost trajectories derived from retrograde periodic orbits around [Formula: see text] are taken as a starting point for the escape of the Earth-Moon system and, as the vehicle exits the sphere of influence of Earth, the deployment of an adjustable solar sail guarantees the interception of the target in a predetermined position and time of flight. Different sail loadings (164, 61 and 30 g/m(2)) are tested and a case study to the NEA 65,803 Didymos is presented. The results show economies in the velocity increments required by the mission up to 8.48%, although a longer time of flight might be needed depending on the sail loading.