Deflecting earth-threatening asteroids using the solar collector: An improved model

Abstract

The solar collector (SC) is a proposed method of altering the solar orbits of Earth-threatening asteroids. A jet of material, energized by concentrated sunlight, would alter the asteroid's trajectory as a consequence of Newton's Third Law. A model, first applied during a 2007 NASA study, is further developed and applied to various classes of asteroids. Calculated jet velocities compare favorably with measurements of comet-tail ejection velocities. One of the parameters of the refined model is the electromagnetic (EM) penetration depth in the asteroid surface material. Measurements of EM penetration depth in a sample of the Allende meteorite are reported and applied to the calculations. The model predicts that the SC will be most effective in diverting asteroids rich in water ice, marginal in the case of silicate-rich asteroids and ineffective in the diversion of iron-rich asteroids. It is not impossible that the SC could be employed in efforts to steer very small ice-rich asteroids into high Earth orbit for purposes of resource retrieval. Possible limitations on SC lifetime caused by energized-jet material impacting on optical surfaces, results of other model studies and recommendations for future research are discussed.