This is one of three fuel cell power plants that produced electrical power for a space shuttle orbiter. They were located under the payload bay floor in the mid-fuselage behind the crew compartment. The fuel cell transformed hydrogen and oxygen into electricity in the top (power) section, and the accessory section at the bottom monitored the chemical reaction and temperature of the unit and also removed heat and water produced by the process. The water was stored in tanks for use by the onboard environmental control and life support system and the crew.
NASA transferred this extra orbiter fuel cell to the Museum in 2012 when the space shuttle program ended. Three other fuel cells remain installed inside the orbiter Discovery, on display at the Museum’s Steven F. Udvar-Hazy Center.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.