Abstract The advancement of dynamical systems theory has significantly deepened and matured research on Earth–Moon low-energy transfer trajectories. Leveraging their inherent energy efficiency, such trajectories substantially reduce the required velocity increment (Δv), thereby offering substantial engineering value for lunar missions. This paper first surveys existing and planned low-energy Earth–Moon transfer missions worldwide. Subsequently, under realistic engineering constraints imposed by Manned lunar landing requirements—and within the plane restricted four-body problem (PR4BP) framework—we systematically discretize and densely sample key design parameters, including spacecraft initial position and velocity, transfer duration, and solar initial phase. Integrating nonlinear programming with a multi-segment shooting method, we conduct a comprehensive numerical search for feasible transfers with durations≤100 days and terminal states satisfying retrograde lunar orbit (RLO) conditions—covering both lunar gravity-assist and direct-transfer configurations. The resulting time–velocity solution set enables identification of optimal trajectories that jointly satisfy dynamical robustness, ground-based tracking and control feasibility, and propellant efficiency, thus providing actionable theoretical foundations and practical guidance for the Earth–Moon transit segment of Manned lunar missions.

With NASA's Artemis program and international collaborations focused on building a sustainable infrastructure for human exploration of the Moon, there is a growing demand for lunar exploration and complex spaceflight operations in cislunar space. However, designing efficient transfer trajectories between the Earth and the Moon remains complex and challenging. This investigation focuses on developing a dynamically informed framework for constructing low-energy transfers in the Earth-Moon-Sun Bicircular Restricted Four-body Problem (BCR4BP). Techniques within dynamical systems theory and numerical methods are exploited to construct transfers to various cislunar orbits. The analysis aims to contribute to a deeper understanding of the dynamical structures governing spacecraft motion. It addresses the characteristics of dynamical structures that facilitate the construction of propellant-efficient pathways between the Earth and the Moon, exploring periodic structures and energy properties from the Circular Restricted Three-body Problem (CR3BP) and BCR4BP. The investigation also focuses on constructing families of low-energy transfers by incorporating electric propulsion, i.e., low thrust, in an effort to reduce the time of flight and offer alternative transfer geometries. Additionally, the investigation introduces a process to transition solutions to the higher fidelity ephemeris force model to accurately model spacecraft motion through the Earth-Moon-Sun system. This research prov

A targeting scheme is presented to build trajectories from a specified Earth parking orbit to a specified low lunar orbit via a low-energy transfer and up to two maneuvers. The total transfer delta V (velocity) is characterized as a function of the Earth parking orbit inclination and the departure date for transfers to each given low lunar orbit. The transfer delta V (velocity) cost is characterized for transfers constructed to low lunar polar orbits with any longitude of ascending node and for transfers that arrive at the Moon at any given time during a month.

The aim of this work is to compute low-energy trajectories in the Earth–Moon system within the framework of the Circular Restricted Three-Body Problem. It is known that this model admits five equilibrium points, in a proper reference system. We look for connection paths between the neighbourhood of a given collinear libration point and one of the primaries. We focus on the point L 1 and on the point L 2, whose linear behaviour is of type center × center × saddle. We consider Lindstedt–Poincare series expansion as main procedure to compute invariant stable manifolds associated with periodic and quasi-periodic orbits around L 1 and L 2. It turns out that direct lunar transfers are allowed only from certain regions on the Moon’s surface and that the most advantageous connections between the Earth and a libration point orbit take place at the local maxima of the function distance between the Earth and a given stable manifold.

A Robust Finite Fourier Series (R-FFS) approach is developed for fast generation of Earth-Moon trajectories using continuous low thrust. Each component of the position vector is approximated using a finite Fourier series as a function of time; these approximations are then used to design a trajectory that satisfies the equations of motion and the constraints, at discrete points, as well as the problem boundary conditions. The R-FFS method leverages the three body problem characteristics to achieve all the required plane change without the use of propulsion. The trajectory is divided into phases. The phase of the trajectory near the L1 Lagrange point is designed first and is always a thrust-free phase. This thrust-free phase is optimized to achieve the required plane change, enabling planar trajectories in the other phases. The initial guess needed by the solver, in the escape and capture phases, is generated using an analytic approximation developed in this paper. The numerical results show that the R-FFS can generate three dimensional transfers to high lunar orbits, low lunar orbits, and Halo orbits, while meeting constraints on the maximum thrust level of the engine.