The development of an advanced green monopropellant propulsion system could have significant benefits to a wide range of NASA space missions, from deep space satellites to manned space vehicles. However, the state-of-the-art thruster materials, refractory metals, cannot withstand AF-M315E combustion environment at temperatures of >2000°C without loosing their mechanical integrity. Sienna Technologies, Inc, in collaboration with Moog-ISP, proposes to develop a revolutionary refractory metal-ceramic FGM material and an AF-M315E advanced green monopropellant thruster. In Phase I we will demonstrate a refractory metal-ceramic FGM through materials design and microstructural control that meets the requirements for thrust chamber for AF-M315E monopropellant. In Phase II we will fine-tune the FGM material properties to maximize the mechanical strength and thermochemical stability; and design, fabricate, and test a working FGM thruster in collaboration with Moog-ISP.