Autonomous and Robust Orbit-keeping for Small Body Missions

TL;DR

This paper introduces a robust, analytical control law for autonomous orbit-keeping around small bodies, enabling precise, fuel-efficient spacecraft operations with minimal thruster use and real-time applicability.

Contribution

It presents a novel, sliding mode control-based approach for autonomous orbital maintenance that accounts for practical constraints and is validated through asteroid Bennu orbit-keeping examples.

Findings

Achieves precise orbit maintenance with minimal fuel.

Demonstrates robustness against disturbances and noise.

Suitable for real-time autonomous operations.

Abstract

This article presents a path-following control law for autonomous orbital maintenance of small body missions. The control law is robust, stable, and capable of controlling only the orbital geometry, allowing the spacecraft to operate with idle-thruster periods. It is entirely analytical and suitable for real-time operations. The control law is inspired by the two-body problem and uses sliding mode control theory to ensure robustness against bounded disturbances. Practical considerations, such as measurement noise, thruster limitations, and hysteresis-based control switching, are taken into account. The proposed control law is demonstrated and validated through several examples, including orbit-keeping around the asteroid Bennu, showing its feasibility and efficiency for small body missions. The results indicate that the control law can achieve precise and safe orbit maintenance with minimal fuel consumption, making it a valuable asset for autonomous space missions.