Hydrocode Model Representations of Asteroid 101955 Bennu

Abstract:

101955 Bennu is the intended target of the 2016 NASA OSIRIS-REx sample return mission. The current state of knowledge of the object is as good or better than what might be available for a potentially hazardous asteroid during the planning of a mitigation attempt. It is a 492-m-diameter B-type carbonaceous asteroid most similar in spectral features to CI and CM meteorites (Hergenrother et al. 203, 2014), with a ridged spheroidal shape that is known to a resolution of 25 m from Aricebo and Goldstone radar data. Bennu is a potentially hazardous asteroid, with an impact probability of 1:37000, and possible impact dates in the late 2100's, according to the JPL SENTRY database. Modeling a deflection attempt against a hypothetical Bennu-like asteroid is part of the NASA-NNSA inter-agency collaboration on impact hazard mitigation. Here we develop a best-estimate design reference model of Bennu based on the OSIRIS-REx DRA (Hergenrother et al. 2014) and available material models, identify uncertainties in the object's composition, and estimate their effects on mitigation planning.