Directed energy missions for planetary defense

Abstract

Directed energy for planetary defense is now a viable option and is superior in many ways to other proposed technologies, being able to defend the Earth against all known threats. This paper presents basic ideas behind a directed energy planetary defense system that utilizes laser ablation of an asteroid to impart a deflecting force on the target. A conceptual philosophy called DE-STAR, which stands for Directed Energy System for Targeting of Asteroids and exploration, is an orbiting stand-off system, which has been described in other papers. This paper describes a smaller, stand-on system known as DE-STARLITE as a reduced-scale version of DE-STAR. Both share the same basic heritage of a directed energy array that heats the surface of the target to the point of high surface vapor pressure that causes significant mass ejection thus forming an ejection plume of material from the target that acts as a rocket to deflect the object. This is generally classified as laser ablation. DE-STARLITE uses conventional propellant for launch to LEO and then ion engines to propel the spacecraft from LEO to the near-Earth asteroid (NEA). During laser ablation, the asteroid itself provides the propellant source material; thus a very modest spacecraft can deflect an asteroid much larger than would be possible with a system of similar mission mass using ion beam deflection (IBD) or a gravity tractor. DE-STARLITE is capable of deflecting an Apophis-class (325 m diameter) asteroid with a 1-to 15-year targeting time (laser on time) depending on the system design. The mission fits within the rough mission parameters of the Asteroid Redirect Mission (ARM) program in terms of mass and size. DE-STARLITE also has much greater capability for planetary defense than current proposals and is readily scalable to match the threat. It can deflect all known threats with sufficient warning.

Conceptual Design for Deflecting a Potentially Hazardous Asteroid with a Space Duster

“…It uses an ultrasonic scanning device to determine the best region with the optimal regolith in a similar manner to industrial uses. Because the harvesting of dust is a time-consuming operation, the production of the thrust would be a very crucial part of this instrument [16].…”

Peaceful Use of Lasers in Space: Context-Based Legitimacy in Global Governance of Large Technical Systems

“…As of 2020, over 23,000 near-earth asteroids and 110 near-earth comets are on record and are being monitored, with planet defenders tirelessly searching for other potentially hazardous objects that could impact Earth. 5 From a technical point of view, lasers have the potential to become critical elements of planetary defense, as they may be used to deflect asteroids by the photon pressure method (Lubin et al, 2016;Zhang et al, 2016Zhang et al, , 2019. In relation to this, they can be used to explore asteroids' internal composition through laser-induced ablation, whereby facilitating other possible methods of deflection.…”

Interstellar Communication Network. I. Overview and Assumptions

“…Freeman Dyson proposed the "astrochicken", a self-replicating one-kilogram spacecraft (Nygren 2015). Taken to the extreme (2020 perspective), probes are planned with masses of order gram, using a light sail for propulsion in combination with a powerful laser (Lubin et al 2016;Popkin 2017). If lightweight sail materials and technologies such as graphene or an aluminium lattice can be made into a sail with a mass to surface area of <g m −2 , it is possible to accelerate and decelerate from (and to) 0.01 c solely with stellar photons and magnetic fields Forgan et al 2018).…”