Kerosene or hydrogen? Comparative analysis of upper stages

Based on statistical data from existing designs or detailed design studies of oxygen-kerosene Upper Stages (US) made by RSC Energia for space rockets and planned oxygen-hydrogen US to be built by RSC Energia and Khrunichev Center, the paper demonstrates feasibility of simple engineering estimates for final masses of the new alternative designs of US using these propellants as a function of their operational propellant load. Its findings show that it is not correct to use for US performance comparisons similar statistical dependencies that are based on the use of combined data for US and rocket stages of space launch vehicles. It demonstrates the inefficiency of using hydrogen for our country’s US of the two-stage acceleration-deceleration system of the manned lunar vehicle.