Reading : NASA says 170,300 g of Oxygen (O2) per person is needed for a 6-month mission. Space X, a private company that partners with NASA claims the law does not apply in space and that only 127,500 grams of water are needed. How many grams of water (H2O) is needed to meet the Oxygen demands? Stoichiometry //Is NASA’s calculation of 151,200 grams of water going to produce enough oxygen through electrolysis for 6 months or is Space X’s claim and calculation of 127,500g accurate?