▁replacement ▁for ▁the ▁pal let ▁was ▁planned , ▁since ▁the ▁Station - to - Sh utt le ▁Power ▁Transfer ▁System ▁provided ▁much ▁of ▁the ▁same ▁ab ilities , ▁and ▁the ▁ 2 0 1 1 ▁ret irement ▁of ▁the ▁sh utt le ▁fleet ▁made ▁it ▁redundant . ▁ ▁Spec ifications ▁ ▁The ▁E DO ▁t anks ▁stored ▁ 3 6 8 ▁pounds ▁( 1 6 7   kg ) ▁of ▁liquid ▁hydro gen ▁at ▁- 4 1 8 ▁degrees ▁F ahren heit ▁(- 2 5 0   ° C ), ▁and ▁ 3 , 1 2 4 ▁pounds ▁( 1 , 4 1 7   kg ) ▁of ▁liquid ▁o xygen ▁at ▁- 2 8 5 ▁degrees ▁F ahren heit ▁(- 1 7 6   ° C ). ▁ ▁Total ▁empty ▁weight ▁of ▁the ▁system ▁was ▁ 3 , 5 7 1 ▁pounds ▁( 1 , 6 2 0   kg ). ▁When ▁filled ▁with ▁cry og ens , ▁the ▁system ▁weight ▁was ▁approximately ▁ 7 , 0 0 0 ▁pounds ▁( 3 . 2 ▁t ). ▁ ▁Use ▁ ▁O xygen ▁and ▁hydro gen ▁were ▁supplied ▁to ▁the ▁orb iter ' s ▁three ▁elect rical ▁power ▁generating ▁fuel ▁cells , ▁where ▁they ▁were ▁converted ▁into ▁sufficient ▁elect rical ▁energy ▁to ▁support ▁the ▁average ▁ 4 ▁family - member ▁house ▁for ▁approximately ▁ 6 ▁months . ▁ ▁About ▁ 3 , 0 0 0 ▁pounds ▁of ▁pure ▁drink ing ▁water ▁was ▁also ▁produced ▁by ▁the ▁fuel ▁cells . ▁ ▁Miss ions ▁with ▁the