Asteroid/Comet Classification for Mining Purposes

New information about the internal structures of asteroids and comets continues to be obtained. Meanwhile, renewed emphasis on exploration of the Solar System is sharpening the focus on extra-terrestrial raw materials to facilitate the process. The overall energy cost will be reduced significantly by maximizing usage of locally available resources. This paper refines a previously proposed classification of asteroids and comets for mining purposes, based on updated information about their mechanical properties. Class 0, ice composites, appears less homogeneous than before. Class 1, friable rock, may be the largest group, at the expense of Class 0 and especially Class 2, hard rock. Class 3 remains metallic, divided according to the amount of rock present. Additional information is needed for complete classification, so asteroid/comet mining operations can be planned realistically.