Stock Photo - 10/25/1999 ___ The Zero Emissions ZE transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock_up orbiter named Explorer left and a stack of solid rocket boosters and external tank right, typically used on Shuttle launches. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center´s Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by_product exhaust from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel_powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept