Solid propellants are solid-state mixtures of fuel and oxidizer that are ignited to propel rockets. The prediction of solid propellant burning rates is useful in rocket design, but it is also a challenge because of the complex physical and chemical processes that occur as the propellant burns. The project objective was to establish an understanding of the modeling of solid propellant combustion. A thorough literature review of the fundamental processes behind solid propellant combustion was first conducted, along with a review of current combustion models. An analytical model capturing the burning process of solid propellant was then created in MATLAB. This model takes in the formulation of the propellant and uses a tri-flame and a twophase approach to calculate the propellant burning rate. Small strands of ammonium perchlorate composite propellant were additionally burned and studied to validate this analytical model. Numerical simulations conducted in ANSYS Fluent were further used to support the analytical model and to establish the impact of different material properties on the propellant burning rate. The generated models will be used in the future to help identify which solid propellant formulations to use for specific applications.