This paper discloses the methodology and the preliminary results achieved in the framework of the H2020 STRATOFLY Project on the design of the Thermal Protection System of the MR3 vehicle. The results of the aero-thermal assessment performed throughout the trajectory clearly indicate the air-intake leading edges as the most critical area, thus dedicated Thermal Protection System alternatives have been explored. Specifically, solutions coupling high-temperature materials (mainly CMC and tungsten with different emissivity paints) with Liquid Metals Heat Pipe arrangements are modelled. Eventually, the effectiveness of the designed solutions is verified with detailed numerical simulation. The design which includes the air-intake main structure made of CMC material and integrating Nickel - Potassium heat pipe results to be the most promising solution to withstand the high thermal loads experienced by STRATOFLY MR3 throughout its Mach 8 long-haul route
