Orbital Propellant Depots Enabling Lunar Architectures Without Heavy-Lift Launch Vehicles

摘要

Many human lunar exploration architectures, both flown and conceptual, use at least one heavy-lift launch vehicle to deliver flight hardware to low Earth orbit. There exists a technology, however, that allows these large exploration missions to be performed without the use of a heavy-lift launch vehicle: propellant transfer. This study presents a methodology to incorporate propellant transfer into conceptual design of lunar architectures through the use of a low-Earth-orbit propeUant depot. This technology is then applied to a two-launch human lunar architecture without a heavy-lift launch vehicle. The results show that not only is a lunar architecture without a heavy-lift launch vehicle feasible with a propellant depot, but it can also improve the capability to deliver payload to the surface over an architecture that includes a heavy-lift launch vehicle without a propellant depot. The optimal lunar lander for this architecture is a hypergolic lander with a deck height of only 1.53 meters that performs only a portion of the descent burn, while the trans-lunar injection stage performs the other portion. The hypergolic propellant allows for a simpler, less expensive propulsion system, a volumetrically smaller lander, and enables the use of the existing hypergolic propellant transfer technology.