More than a Manipulator: Planning Propellant-Free Attitude Maneuvers for Free-Floating Spacecraft

2026-07-13

AI Summary

This study challenges the conventional view of robotic manipulators as mere disturbance sources in spacecraft attitude control by systematically demonstrating their potential as redundant or even primary actuators. Focusing on scenarios involving high relative-mass payload capture, the work proposes a multifunctional control framework leveraging the manipulator for complex attitude maneuvers without propellant consumption. A nonlinear trajectory optimization problem is formulated, incorporating joint limits and collision-avoidance constraints, and solved via an interior-point method. Momentum-torque envelope analysis is employed to quantitatively compare the attitude control authority of the manipulator against that of a reaction wheel assembly. Simulation results generate diverse detumbling and reorientation trajectories, validating the feasibility of achieving intricate spacecraft attitude maneuvers solely through manipulator motion.

Abstract

Spacecraft attitude control is traditionally achieved using momentum exchange devices or propellant-consuming thrusters. Meanwhile, a growing number of missions require robotic manipulators, which are typically treated as disturbance sources to be rejected rather than as actuators for spacecraft reorientation. This work investigates the use of manipulator motions for propellant-free attitude control by formulating a trajectory optimization problem with critical joint and collision avoidance constraints. Using an interior point solver for the resulting nonlinear program, complex slew and detumble trajectories are demonstrated for a range of spacecraft-manipulator systems with varying kinematic complexity and mass properties. The achievable control authority is compared directly with that of reaction wheel arrays via momentum and torque envelopes, demonstrating the potential for manipulators to serve as redundant or even primary attitude control systems. This work provides a framework for using manipulators as multipurpose attitude control actuators, with particularly promising applications in in-space assembly and manufacturing when grasping payloads with high relative mass fractions.

Problem

• propellant-free attitude control
• free-floating spacecraft
• robotic manipulator
• attitude maneuver
• momentum exchange

Innovation

• propellant-free attitude control
• free-floating spacecraft
• manipulator-based actuation
• trajectory optimization
• momentum envelope