Self-stabilization of light sails by damped internal degrees of freedom

TL;DR

This paper demonstrates that incorporating damped internal degrees of freedom into light sail designs can passively stabilize their motion during laser propulsion, with minimal heat generation.

Contribution

It introduces a novel approach to passive stabilization of light sails using internal damping, supported by stability analysis and design concepts.

Findings

Passive damping stabilizes lateral sail perturbations

Complex behavior similar to PT-symmetric systems observed

Damping heat production is lower than laser absorption heating

Abstract

We consider the motion of a light sail that is accelerated by a powerful laser beam. We derive the equations of motion for two proof-of-concept sail designs with damped internal degrees of freedom. Using linear stability analysis we show that perturbations of the sail movement in all lateral degrees of freedom can be damped passively. This analysis also shows complicated behaviour akin to that associated with exceptional points in PT-symmetric systems in optics and quantum mechanics. The excess heat that is produced by the damping mechanism is likely to be substantially smaller than the expected heating due to the partial absorption of the incident laser beam by the sail.