A Microwave Thermal Shepherd: Volumetric Heating and Outgassing Thrust on an 85-Metre Asteroid

This paper computes a microwave shepherd that radiates 6,000 W toward an 85 m asteroid of mass 610,954,686 kg, of which a fraction 0.48 is absorbed within a penetration depth of 0.35 m. Heating drives off 0.000384 kg per second of volatile material, producing 0.315 N of recoil and an acceleration of 5.15e-10 m per second squared. Over 3.2 years the system delivers 52 mm per second against a requirement of 22.6 mm per second for a 7,000 km displacement with seven years of warning, a margin ratio of 2.3, a computed separation of 16,096 km and a total heated mass of 38,778 kg. This is a computed study of a deflection system for planetary defence, with no targeting or weapon application. It is simulated, not measured.