Recursive multi-objective optimization of Mars-Earth-Venus trajectories

The NASA exploration roadmap envisions a sustainable human presence beyond Earth orbit with an emphasis on Mars habitation. Establishing an interplanetary transportation system in orbits that periodically intersect Earth and Mars have been under study since 1969 to meet this end, but solutions generally suffer from high Δv requirements, high approach velocities, and unfeasibly long transit times or impractical simplifying assumptions like co-planar, circular orbits. This work seeks to expand investigations to connective low-thrust, low-Δv trajectories that also take advantage of Venusian gravity assists when available to further optimize cyclic systems. By leveraging supercomputing resources, this work also seeks to diverge from studies using cycler templates and explore a larger parameter space for potential solutions that take advantage of realistic planetary ephemeris like plane change maneuvers. To optimize the process, a piecewise multi-objective Newton's method optimization is applied to combinations of planets resulting in several tours per year with less than 7 km/s Δv including Earth departure v. This method is demonstrably better than an even sampling of launch and encounter dates for investigations with limited computational resources. The inclusion of Venus allows the algorithm to take advantage of fortuitous alignments of Venus for plane change maneuvers, reducing the overall cost. Venusian-inclusive tours also provide launch opportunities outside the usual Earth-Mars launch windows.