Recovery of lunar surface access module residual and reserve propellants

The vision for space exploration calls for human exploration of the lunar surface in the 2020 timeframe. Sustained human exploration of the lunar surface will require supply, storage, and distribution of consumables for a variety of mission elements. These elements include propulsion systems for ascent and descent stages, life support for habitats and extra-vehicular activity, and reactants for power systems. NASA KSC has been tasked to develop technologies and strategies for consumables transfer for lunar exploration as part of the exploration technology development program. This paper will investigate details of operational concepts to scavenge residual propellants from the lunar descent propulsion system. Predictions on the mass of residuals and reserves are made. Estimates of heat transfer and boil-off rates are calculated and transient tank thermodynamic issues post-engine cutoff are modeled. Recovery and storage options, including cryogenic liquid, vapor and water are discussed, and possible reuse of LSAM assets is presented.