Light weight materials such as reinforced plastics are rapidly replacing the traditional structural materials such as metals, woods etc. However, in many instances, these materials are flammable and they require modifications to decrease their flammability through addition of flame-retardant components. Environment regulations have restricted the use of halogenated flame-retardant additives, initiating a search for alternative flame-retardant additives. Nanoparticle fillers such as CNTs have shown that they can simultaneously improve both the physical and flammability properties of the polymer nanocomposite. Our multi-scale simulations will explain the physical mechanisms behind the formation of a continuous, stable, protective char layer on the burning surface that acts as a heat shield for the virgin polymer below the layer. The presence of the protective layer is clearly important in the flammability reduction and it also reduces the mass loss rate. Thus it will directly help in development of the next generation commercial fireproofing materials. The proposed computational model is primarily focused towards development of ablation materials to be used in potential space shuttle vehicles such as: Orion. Simulations will be performed to model the evolution of phenolic resin with CNT during the pyrolysis reaction and formation of the char product. The fundamental understanding gained from these simulations will be applied to design a strong interface between the char material and the CNT. A strong char material will act as a thermal insulator and prevent further heating of the shuttle vehicle. In addition, it will also prevent exposure of the underneath virgin material.