LOW-ENERGY CAPTURE OF ASTEROIDS FOR THE LOGISTIC SUPPORT OF FUTURE MARS MISSIONS

Low energy strategies for capturing asteroids and inserting them into orbits in the vicinity of the Sun-Mars L-1/L-2 libration points may be of significant benefit for future Mars missions. Such strategies could deliver resources to Lagrange point staging posts to support future crewed missions. Three asteroid capture strategies are investigated to achieve efficient delivery of asteroid resources. In the first strategy, the target asteroid is assumed to be deflected from its heliocentric orbit using some initial maneuver. Then, with a second maneuver, the candidate asteroid is inserted onto the stable manifold associated with the Sun-Mars L-1/L-2 periodic orbits. In principle it will then be asymptotically captured onto the final target periodic orbit without any propellant consumption. Therefore, the entire transfer trajectory for capturing the candidate asteroid can be designed by patching together the Sun-centered two-body problem and the stable manifold in the Sun-Mars circular restricted three-body problem. Moreover, a Mars flyby is also considered to capture asteroids onto the final periodic orbits around the Sun-Mars libration points. According to the periapsis distance threshold for aerobaking, two asteroid capture strategies using the Mars flyby are considered: a Mars flyby with aerobraking and without aerobraking to enhance the transfer trajectory from the candidate asteroid orbit to the stable manifolds associated with the Sun-Mars L-1/L-2 periodic orbits. Furthermore, all transfers are optimized with a global optimization method, using the total transfer cost as the objective function. Results show that the Mars flyby can enable some asteroids to be captured with a lower cost than the asteroid capture strategy without a Mars flyby in terms of energy requirements.