Requirements Analysis of Propulsion Systems for Lunar-Exploration Mission

Requirements of a propulsion system for lunar-exploration missions using a launch vehicle, the development of which has recently started in Korea, were conceptualized. A new three-stage-to-orbit launch system, the Korea Space Launch Vehicle 2 will be a middle-class launch vehicle in that its expected payload capacity to low Earth orbit will be about 2.6 tons. The Korea Space Launch Vehicle 2 is under development and may possibly launch a lunar orbiter and a lander within 10-15 years. Considering some of the limitations and requirements a new space-propulsion system must be developed, and it has been found that a H2O2/kerosene-bipropellant rocket is the optimum propulsion system among several types of chemical rockets. The optimum thrust and burn-time requirements for orbital transfers and landing using H2O2/kerosene-bipropellant rockets were also derived by mass budget design and three-degree-of-freedom orbit-trajectory calculations. It has been found that, using the Korea Space Launch Vehicle 2,1800 N-class H2O2/kerosene-bipropellant propulsion system with a continuous burn time of more than 340s and an accumulated burn time of more than 710 s needs to be developed for the lunar-exploration missions.