The challenges of designing, developing, and fielding man-rated propulsion systems continue to increase as NASA's Vision for Space Exploration Program moves beyond the Space Shuttle and RSRM. The number and type of different propulsion elements required are significant, and predicting internal solid motor behavior and characteristics and assessing external environments (e.g., plume impingement on vehicle structures and launch acoustic loading) is a priority. Our proposed innovation will enhance existing engineering software by combining new physical modeling capabilities with appropriate boundary conditions to create a novel toolset for complex multi-phase solid rocket analyses. The innovation will be based on the Loci/Chem multi-physics analysis package and will utilize new Loci features, new multi-phase flow models, theoretical and phenomenological boundary conditions, and modified real gas equations of state to create a unique software tool for particle breakup, surface heat transfer with particle deposition, launch environment characterization, and nozzle erosion for next generation solid motors. Our research products will provide NASA with the important capability to simultaneously analyze solid propellant combustion, heat transfer, launch acoustics, and nozzle erosion within a single unified numerical framework. We will validate the approach using appropriate two phase flow problems to achieve a TRL range of 3-4.