Low-Power Laser Sailing for Fast-Transit Space Flight

Space exploration is of paramount importance to advancing fundamental science and the global economy. However, today's space missions are limited by existing propulsion technologies. Here, we examine the use of laser-driven light sailing for agile Earth orbital maneuvering and for fast-transit exploration of the solar system and interstellar medium. We show that laser propulsion becomes practical at laser powers ≥100 kW and laser array sizes ∼1 m, which are feasible in the near term. Our analysis indicates that lightweight (1-100 g) wafer-scale (∼10 cm) spacecraft may be propelled by lasers to orbits that are beyond the reach of current systems. We discuss material requirements and photonic designs and introduce new figures of merit. We show that lightsails made of silicon nitride and boron nitride are particularly well suited for the discussed applications. Our architecture may pave the way to ubiquitous Earth orbital networks and fast-transit low-cost missions across the solar system.