The overall objective of the proposed work is to provide a better understanding of the transport of ejected lunar regolith during spacecraft landing on extraterrestrial bodies (Moon, Mars, asteroids, etc.) and to incorporate this knowledge into a first-principles model for wide particle size distributions. In order to develop this model, computer simulations using both the discrete element method and continuum theory, along with experimental data, will be used. This model will then be transferred to NASA engineers for use as a practical predictive tool in a variety of scenarios to assist in the design of systems to mitigate the effects of regolith ejection. Such a predictive tool is crucial for the safety and future of space exploration.