Optimization of body configuration and joint-driven attitude stabilization for transformable spacecrafts under solar radiation pressure

TL;DR

This paper tackles attitude control of transformable spacecraft under solar radiation pressure by addressing attitude–joint coupling. It introduces SRP-based joint angle optimization to realize arbitrary SRP force/torque and momentum damping control via joint actuation, both formulated for general front-face SRP reception. Numerical simulations validate that the methods can achieve neutrally stable equilibrium attitudes and stabilizing damping without propellant use, significantly enhancing orbit and attitude control capabilities. The results demonstrate a practical framework for exploiting redundant joints to maximize SRP utility in propellant-free propulsion scenarios.

Abstract

A solar sail is one of the most promising space exploration system because of its theoretically infinite specific impulse using solar radiation pressure (SRP). Recently, some researchers proposed "transformable spacecrafts" that can actively reconfigure their body configurations with actuatable joints. The transformable spacecrafts are expected to greatly enhance orbit and attitude control capability due to its high redundancy in control degree of freedom if they are used like solar sails. However, its large number of input poses difficulties in control, and therefore, previous researchers imposed strong constraints to limit its potential control capabilities. This paper addresses novel attitude control techniques for the transformable spacecrafts under SRP. The authors have constructed two proposed methods; one of those is a joint angle optimization to acquire arbitrary SRP force and torque, and the other is a momentum damping control driven by joint angle actuation. Our proposed methods are formulated in general forms and applicable to any transformable spacecraft that has front faces that can dominantly receive SRP on each body. Validity of the proposed methods are confirmed by numerical simulations. This paper contributes to making most of the high control redundancy of transformable spacecrafts without consuming any expendable propellants, which is expected to greatly enhance orbit and attitude control capability.

Figures (11)

• Figure 1: Nomenclature for body components and their positions
• Figure 2: Three factors for SRP force (from left): specular, diffusive, absorptive
• Figure 3: Definitions of coordinate related to attitude motion
• Figure 4: Model of a transformable solar sail used in the simulation
• Figure 5: Initial guess of SRP-based joint angle optimization