Comparative analysis of asteroid-deflection approaches

Five potential methods of preventing an asteroid from colliding with Earth—Kinetic Impactor (KI), Ion Beam Deflection (IBD), Gravity Tractor (GT), Enhanced Gravity Tractor (EGT), and Laser Ablation (LA)—are compared, with the objective of helping to inform a NASA decision regarding which technology or technologies could be demonstrated in space on the proposed 2019 Asteroid Robotic Redirect Mission (ARRM). Three design blocks are considered, which differ in the power available to the deflection technology and the mass at low-Earth orbit. We plot the required warning time (up to 30 years between discovery of the hazard and potential collision with Earth) vs. asteroid diameter for each of four technologies (gravity tractor without enhancement is considered only as a trim/verification candidate) under each design block, and illustrate sensitivities of results to important parameters.