Systematic Low-Thrust Trajectory Optimization for a Multi-Rendezvous Mission using Adjoint Scaling

TL;DR

This paper presents a systematic approach using indirect optimal control methods and adjoint scaling to optimize low-thrust trajectories for multi-asteroid rendezvous missions, improving initial guess generation and overall efficiency.

Contribution

It introduces an adjoint scaling method for initial trajectory guesses and demonstrates its effectiveness in multi-asteroid mission optimization.

Findings

Effective initial guess generation for complex trajectories

Validated methods through numerical examples with multiple asteroids

Improved fuel efficiency in low-thrust multi-rendezvous missions

Abstract

A deep-space exploration mission with low-thrust propulsion to rendezvous with multiple asteroids is investigated. Indirect methods, based on the optimal control theory, are implemented to optimize the fuel consumption. The application of indirect methods for optimizing low-thrust trajectories between two asteroids is briefly given. An effective method is proposed to provide initial guesses for transfers between close near-circular near-coplanar orbits. The conditions for optimality of a multi-asteroid rendezvous mission are determined. The intuitive method of splitting the trajectories into several legs that are solved sequentially is applied first. Then the results are patched together by a scaling method to provide a tentative guess for optimizing the whole trajectory. Numerical examples of optimizing three probe exploration sequences that contain a dozen asteroids each demonstrate the validity and efficiency of these methods.