Microgravity ethanol droplet combustion experiements were performed at the NASA 2.2 s droptower in Cleverland, OH to investigate the formation or sootshell and it its attendant influences on the burning behavior and radiative heat transfer. Measurements include the burning rate, soot standoff ratio, soot volume fraction, soot temperature.. and radiative heat losses, These experiments demonstrated strong influence of inert gas substitution (that caused changes in the thermophysical properties and temperature) between nitrogen and argon. The experimentally measured soot standoff ratio (SSR) for the argon inert experiment wits similar to 1.4, whereas the value for the nitrogen inert experiment was similar to 2.5. The SSR. wits ,,o calculated using, balance among Stefan, thermophoretic, and diffusiophoretic fluxes, This analysis represents tile first quantitative study in which diffusiophoretic transport was considered using experimentally determined gas-phase temperature distributions for tile analysis of sootshell formation. The computed values of the SSR. art) in excellent agreement with the experimental measurements. The location of sootshell influences the radiative heat transfer from the flame to the droplet and to the surrounding environment and can modify tile burning rate.