The key mechanism behind nano engineered propellants is the incorporation of nanostructures like metallic nanoparticles, carbon nanotubes, and nano-oxides into the propellant matrix. These nanoparticles can act as catalysts, increasing the rate of combustion and energy release. Additionally, the uniform distribution of these nanomaterials within the propellant can lead to a more controlled and efficient burn, thereby maximizing the thrust generated.