The Poynting-Robertson Effect on Solar Sails

TL;DR

This paper analyzes how the Poynting-Robertson effect influences the trajectories and orbital dynamics of solar sails, highlighting its significance at relativistic orders and implications for sail navigation and control.

Contribution

It provides a detailed relativistic analysis of the Poynting-Robertson effect on solar sail trajectories, including escape and bound orbits, and discusses control strategies for non-Keplerian orbits.

Findings

The Poynting-Robertson effect causes solar sails to slow down and spiral towards the sun.

The effect is dominant at order v^{rown}/c, surpassing other relativistic effects.

Periodic adjustments are more feasible than tilt counter-balancing for orbit control.

Abstract

We consider a special relativistic effect, known as the Poynting-Robertson effect, on various types of trajectories of solar sails. Since this effect occurs at order $v^{\phi}/c$, where $v^{\phi}$ is the tangential speed relative to the sun, it can dominate over other special relativistic effects, which occur at order $v^2/c^2$. While solar radiation can be used to propel the solar sail, the absorbed portion of it also gives rise to a drag force in the tangential direction. For escape trajectories, this diminishes the cruising velocity, which can have a cumulative effect on the heliocentric distance. For a solar sail directly facing the sun in a bound orbit, the Poynting-Robertson effect decreases its orbital speed, thereby causing it to slowly spiral towards the sun. We also consider this effect for non-Keplerian orbits in which the solar sail is tilted in the azimuthal direction. While in principle the drag force could be counter-balanced by an extremely small tilt of the solar sail in the polar direction, periodic adjustments are more feasible.