Thermal insulation is widely employed to prevent catastrophic breakdowns that may take place during rocket mission. Its success highly dependent on the optimization of the polymeric ablative composition in the insulator that used in solid rocket motors systems (SRMs). Currently, a massive amount of researches have been conducted to improve thermal protection efficiency through advanced composite materials, especially those applied in rocket engine insulation. This paper gathers and investigates many of the recently published data regarding conventional insulators like nitrile rubber (NBR),,ethylene-propylene-diene- monomer.rubber (EPDM),.silicone rubber,.and polyurethane (PU) as elastomeric.heat.shielding materials.(EHSM). Besides, a comparison between these selected insulators is conducted based on tensile strength, elongation, ablation rate, thermal conductivity, and density shows the effect of these properties on the total effectiveness of the insulation. This article is of great importance to readers interested in the domain of heat-shielding materials, covering the recent advanced composite materials used for ablative insulating systems in SRMs. Moreover, future trends including the employment of innovative fillers, like metal-organic frameworks (MOFs), in rubber composites are also discussed.