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The Engagement Space for Countermeasures Against Potentially Hazardous Objects (PHOs)

W. F. Huebner, D. C. Boice, P. Bradley, S. Chocron, R. Clement, A. Ghosh, P. T. Giguere, R. Goldstein, J. A. Guzik, L. N. Johnson, J. J. Keady, J. Mukherjee, W. Patrick, C. Plesko, M. Tapley, J. D. Walker, R. P. Weaver, K. Wohletz

Protecting the Earth against Collisions with Asteroids and Comet Nuclei, In: A. M. Finkelstein, W. F. Huebner, V. A. Shor (Eds) Proceedings of the International Conference “Asteroid-Comet Hazard-2009”, StP: Nauka, 337–346 (2010)

Keywords: Very Long Baseline Interferometry (VLBI), Near Earth Objects (NEOs), countermeasures, potentially hazardous objects (PHOs), asteroids, comet nuclei, a collision course with Earth, hyper-velocity impacts, surface and subsurface conventional explosions, stand-off nuclear explosions, surface nuclear explosions, subsurface nuclear explosions, momentum transfer, complete deflection of a PHO, destruction of a PHO, maximum dispersal of the fragments, methods and procedures for applying counter-measures, a multi-dimensional engagement space, dimensions and measures of the engagement space, reaction time of the PHO, the size of the PHO, chemical composition of the PHO, physical structure of the PHO, shape of the PHO, spin state of the PHO, hyper-velocity kinetic impactors, intercept missions, deploying chemical or nuclear explosives, rendezvous missions, intercept missions

About the paper Full text


We have proposed a comprehensive plan for counter-measures against PHOs: asteroids and comet nuclei on a collision course with Earth. Countermeasures include hyper-velocity impacts; surface and subsurface conventional explosions; and stand-off, surface, and subsurface nuclear explosions. We consider momentum transfer for complete deflection of a PHO as well as destruction of it with maximum dispersal of the fragments. Methods and procedures for applying counter-measures depend on many variables that are defined by a multi-dimensional engagement space. The dimensions and measures of the engagement space include the reaction time, the size of the PHO, its chemical composition, physical structure, shape, whether it is a binary, and its spin state. Reaction time is one of the most important variables, followed by the spin state and the size of the object. The type of countermeasures that would be effective depends heavily on the engagement space. Hyper-velocity kinetic impactors require intercept missions. The preferred methods of deploying chemical or nuclear explosives require rendezvous missions; however, if the available reaction time is too short, intercept missions must be chosen