Directed energy planetary defense

Directed Energy (DE) systems offer the potential for true planetary defense from small to km class threats. Directed energy has evolved dramatically recently and is on an extremely rapid ascent technologically. It is now feasible to consider DE systems for threats from asteroids and comets. DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) is a phased-array laser directed energy system intended for illumination, deflection and compositional analysis of asteroids [1]. It can be configured either as a stand-on or a distant stand-off system. A system of appropriate size would be capable of projecting a laser spot onto the surface of a distant asteroid with sufficient flux to heat a spot on the surface to approximately 3,000 K, adequate to vaporize solid rock. Mass ejection due to vaporization creates considerable reactionary thrust to divert the asteroid from its orbit. DE-STARLITE is a smaller stand-on system that utilizes the same technology as the larger standoff system, but with a much smaller laser for a dedicated mission to a specific asteroid. DE-STARLITE offers a very power and mass efficient approach to planetary defense. As an example, a DE-STARLITE system that fits within the mass and size constraints of the Asteroid Redirect Mission (ARM) system in a small portion of the SLS block 1 launch capability is capable of deflecting an Apophis class (325 m diameter) asteroid with sufficient warning. A DE-STARLITE using the full SLS block 1 launch mass can deflect any known threat.