Evaluation of Liquid Hydrogen/Hydrogen Peroxide Propellant Combination for Advanced Launch Vehicle Upper Stage

Hydrogen peroxide (H2O2) is a dense, storable oxidizer, but its suitability for high-energy upper stages is limited. This study evaluates liquid hydrogen–hydrogen peroxide (LH2/H2O2) as an alternate propellant using KSLV-II as the reference vehicle. Propulsion performance was analyzed with NASA CEA and RPA, while staging and MER methods assessed system-level effects. The results show that the specific impulse decreases from 465 s (LH2/LOX) to 372~382 s with H2O2, but structural efficiency improves as the coefficient drops from 0.162 to 0.099~0.102. The payload capacity increases compared with Jet A-1/LOX yet remains below that of LOX. These findings clarify both the advantages and limitations of H2O2 as an upper-stage oxidizer.