Prospects and physical mechanisms for photonic space propulsion

An abundant source of energy in space, electromagnetic radiation can provide spacecraft with a gentle yet persistent thrust for interplanetary and interstellar missions. Early successes with microlaser and solar propulsion platforms confirm their potential for near-Earth and deep space exploration, although practical realization of reliable photonic devices is not trivial. This Perspective outlines the recent achievements and future outlook in the field of photonic space propulsion. We highlight several light-enabled mechanisms of thrust generation via photon-matter interactions such as photonic pressure and ablation, optical gradient forces, light-induced electron emission and others. Finally, we outline some of the key challenges in the area and possible solutions for practical applications.