Considerations with Using Expendable Launch Vehicles for Human Lunar Exploration Missions

Abstract

For America’s renewed effort to establish permanent human presence in the solar system, the use of current or modified Expendable Launch Vehicles (ELV’s) such as the Delta IV Heavy and the Atlas V HLV to lift the components needed to explore the Moon must be considered. The constraints imposed on human exploration architectures using these launch vehicles must be understood at a high level during the initial phases of program definition in order to mitigate cost, schedule and technical risk. Historical data on the masses and performance of the Apollo launch vehicle and spacecraft as well as calculations using the ideal rocket equation for various mass fraction and engine specific impulse (Isp) values will be presented in order to understand sensitivities and potential constraints and impacts for using the currently available or modified ELVs for near-term human exploration of the Moon. Finally, the author will discuss some additional concerns regarding on-orbit assembly, cryogenic boil-off, rendezvous and proximity operations and mating mechanism development that will have to be overcome if ELV’s are to be used for human lunar exploration missions.