EFFICIENT CIS-LUNAR TRAJECTORIES

Twenty years ago, the theoretical notions of low-energy transfers were put to test with the Japanese spacecraft, Hiten. With the successful implementation of the low-energy transfer trajectory discovered by Belbruno, Hiten exposed the available option space for mission designers seeking efficient transfers and planetary captures. Integrated mission designs utilizing these kinds of low-energy transfers would enhance the operational flexibility of an Exploration Platform operating within the Earth-Moon Lagrange Point 2 (EML2) vicinity. This paper provides a brief rationale for the use of low-energy transfers in human space exploration architectures, considering how flexible path architectures, by definition, require finding an architectural "sweet spot" in the convergence of efficiency, resilience, and cost. It then examines the types of high and low energy transfers that could be performed during the operation of such a facility, taking advantage of the natural dynamics of the Earth-Moon system in such a way as to maximize mass delivery while minimizing the propellant used in the transfer. We conclude that in moving human exploration beyond Low Earth Orbit (LEO), the integration of high and low energy transfers in an EML2 exploration platform mission design architecture provides the flexibility to perform meaningful, near-term missions which will inform space-faring nations of the consequences and risks involved in deep-space exploration. Additionally, the surface-destination based missions are allowed to continue to be explored with regard to necessary technology and investment decisions, without having to make the specific investment commitments in the near-term for surface-based missions.