2015-10-292015-10-292015-07-12ICES-2015-226http://hdl.handle.net/2346/64491Bellevue, WashingtonWilliam West, Hamilton Sundstrand Space Systems International (HSSSI), USAMichael Heldmann, Hamilton Sundstrand Space Systems International (HSSSI), USATimothy Scull, Hamilton Sundstrand Space Systems International (HSSSI), USADarren Samplatsky, Hamilton Sundstrand Space Systems International (HSSSI), USAGregory J. Gentry, The Boeing Company, USAMatthew Duggan, The Boeing Company, USAKurt Klaus, The Boeing Company, USAThe 45th International Conference on Environmental Systems was held in Bellevue, Washington, USA on 12 July 2015 through 16 July 2015.This paper will estimate oxygen, nitrogen and water resupply needs for a crewed lunar or Martian surface habitat, assuming relevant mission parameters, current ISS levels of loop closure, assumptions on leakage and venting and the addition of laundry and shower facilities. The paper will then identify lunar and Mars ECLS ISRU candidates and trade ISRU vs. delivery of supplies from earth. Lunar ISRU candidates include water and oxygen from putative lunarpolar ice deposits. Mars ISRU candidates include water, oxygen from ice and nitrogen/argon/oxygen from atmospheric constituents. For given assumptions a crossover point for each constituent will be identified where it will become more advantageous to seek ISRU solutions rather than re-supply from earth.application/pdfengPresentation