Lightsails for Interstellar Travel: Photonics for Propulsion, Thermal Management and Stability

Lightsails are a highly promising spacecraft concept that has attracted interest in recent years due to its potential to travel at near-relativistic speeds. Such speeds, which current conventional crafts cannot reach, offer tantalizing opportunities to probe nearby stellar systems within a human lifetime. Recent advancements in photonics and metamaterials have created a new paradigm for addressing the monumental challenges facing lightsail missions. This review focuses on the models and analysis underpinning propulsion, thermal management and dynamical stability of lightsails. We emphasize that photonics coupled with inverse design substantially enhances lightsail performance compared to plain reflectors. These developments pave the way through a previously inaccessible frontier of space exploration.