Extended Duration Orbiter (prepare for long-term (months) microgravity research aboard Space Station Freedom) has three electrical power generating fuel cells that also produce 3000 pounds of drinking water.
The Extended Duration Orbiter (EDO) program was a project by NASA to prepare for long-term (months) microgravity research aboard Space Station Freedom, which later evolved into the International Space Station. Oxygen and hydrogen were supplied to the orbiter's three electrical power generating fuel cells, where they were converted into sufficient electrical energy to support the average 4 family-member house for approximately 6 months. About 3,000 pounds of pure drinking water was also produced by the fuel cells. 
