Momentum Enhancement Simulations for Hypervelocity Impacts on Sandstone

Abstract Two NASA missions that will be launched in 2022 have spun renewed interest in hypervelocity impact of rocks and metals. This paper is focused in the prediction of the momentum enhancement effect, i.e. the extra momentum acquired by the target due to the ejecta flying off the target in the direction of the impactor. Predicting the momentum enhancement with simulations has been elusive, probably because the target material is rarely well characterized. This paper shows that, given a good knowledge of the properties of the target material and, by adding two essential pieces of the physics (strength of failed material and bulking after failure), the computer simulations can provide good predictions of the momentum enhancement for hypervelocity impact tests performed at Southwest Research Institute.