Theoretical peak performance and optical constraints for the deflection of an S-type asteroid with a continuous wave laser

Abstract

This paper presents a theoretical model to evaluate the thrust generated by a continuous wave (CW) laser, operating at moderate intensity(<100GW/m 2 ), ablating an S-type asteroid made of Forsterite. The key metric to assess the performance of the laser system is the thrust coupling coefficient which is given by the ratio between thrust and associated optical power. Three different models are developed in the paper: a one dimensional steady state model, a full 3D steady state model and a one dimensional model accounting for transient effects resulting from the tumbling motion of the asteroid. The results obtained with these models are used to derive key requirements and constraints on the laser system that allow approaching the ideal performance in a realistic case.

Numerical Study on Asteroid Deflection by Penetrating Explosion Based on Single-Material ALE Method and FE-SPH Adaptive Method

“…However, the gravitational pull of the asteroid was small and had a limited influence on the particle velocity. The escape velocity from the surface is given by [21]: (8) where is the mass of the asteroid, is the universal gravitational constant, and R = 27 m is the asteroid's radius. The calculation shows that the escape velocity from the asteroid's surface is only 2.8 cm/s; therefore, some particles may fly away because the rebound velocity exceeds the escape velocity.…”

“…Therefore, there is an urgent need to develop and validate feasible and effective techniques to prevent an incoming asteroid impact on Earth. Previous studies have proposed a series of asteroid mitigation techniques, such as solar collectors [4,5], laser ablation [6][7][8], ion beam [9], gravity tractors [10][11][12], kinetic impacts [13][14][15][16], conventional explosions [17], nuclear explosions [18][19][20][21][22], and hypervelocity asteroid intercept vehicles (HAIV) [23,24]. A successful mitigation strategy requires accurately predicting the warning time, trajectory, shape, material compositions, and other physical characteristics of asteroids [25,26].…”