End-to-End Lyapunov-Based Eclipse-Feasible Low-Thrust Transfer Trajectories to NRHO

TL;DR

This paper introduces a Lyapunov-based method for designing low-thrust, eclipse-feasible transfer trajectories to the Near Rectilinear Halo Orbit, optimizing for minimal time while respecting eclipse constraints.

Contribution

It presents a novel approach combining Lyapunov control and particle swarm optimization for efficient trajectory generation to NRHO with eclipse constraints.

Findings

Successfully generated minimum-time transfer trajectories respecting eclipse constraints.

Optimized NRHO insertion timing and control parameters for improved mission planning.

Trajectories can be used as initial guesses for high-fidelity NASA trajectory tools.

Abstract

Generating low-thrust transfer trajectories between Earth and the Near Rectilinear Halo Orbit (NRHO), that is selected for NASA's Gateway, can be challenging due to the low control authority available from the propulsion system and the important operational constraint that the duration of all eclipses has to be less than a prescribed 90-minute threshold. We present a method for generating eclipse-feasible, minimum-time solutions to the aforementioned trajectory design problem using a Lyapunov control law. Coasting is enforced during solar eclipses due to both the Earth and Moon. We used particle swarm optimization to optimize the NRHO insertion date, time of flight, and control law parameters according to a cost function that prioritizes 1) convergence to the target orbit, 2) satisfaction of eclipse-duration constraints, and 3) minimization of time of flight. Trajectories can serve as initial guesses for NASA's high-fidelity trajectory design tools such as Copernicus and GMAT.