Near-Earth Asteroids Fly-By Trajectory Optimization For Mining Purposes

The diminishing availability of Earth’s resources has catalyzed the emergence of space mining as a burgeoning industry, with the recent success of missions like OSIRIS-REx underscoring the viability of extracting valuable materials from Near-Earth Asteroids (NEAs). This thesis presents an optimized trajectory framework for asteroid mining missions, focusing on minimizing propellant consumption for reaching these NEAs by means of an electric propulsion system and optimal control theory. The selection process begins with a comprehensive evaluation of potential asteroids, filtering those that are accessible through a Hohmann transfer with a $\Delta v$ requirement below a specified threshold. This criterion ensures the chosen asteroids have orbital parameters that closely align with the mission’s departure conditions, originating from the Sun-Earth Lagrange Point L2. The proposed mission architecture involves a mothership equipped to deploy up to two probes, designed to initiate evaluation operations at asteroids with a Minimum Orbital Intersection Distance (MOID) less than \SI{500000}{\kilo\meter}. The strategy for inter-asteroid transfers includes the use of discontinuous impulsive $\Delta v$ maneuvers at the flyby, not exceeding \SI{1}{\kilo\meter\per\second}, to efficiently navigate between target asteroids. The complexity of gravitational interactions among the considered celestial bodies permits nevertheless the utilization of an autonomous switching function based on the bang-bang control, obviating the necessity for a priori specification of thrust arcs to accomplish the intended rendezvous. For precise modeling of heliocentric trajectories and the positions of celestial bodies, this study utilizes the JPL DE440 ephemeris. This high-fidelity model accounts for the gravitational influences of the Sun and the Earth-Moon System.