Lunar missions using chemical propulsion: System design issues

To transport lunar base elements to the Moon, large high-energy propulsion systems will be required. Advanced propulsion systems for lunar missions can significantly reduce launch mass and increase the delivered payload, resulting in significant launch cost savings. In this report, the masses in low Earth orbit (LEO) are compared for several propulsion systems: nitrogen tetroxide/monomethyl hydrazine (NTO/MMH), oxygen/methane (O2/CH4), oxygen/hydrogen (O2/H2), and metallized O2/H2/Al propellants. Also addressed are payload mass increases enabled with these systems; system design issues involving the engine thrust levels, engine commonality between the transfer vehicle and the excursion vehicle; the number of launches to place the lunar mission vehicles into LEO; and analyses of small lunar missions launched from a single Space Transportation System-Cargo (STS-C) flight.