Shuttle Reference Manual Space Shuttle Orbiter Systems Electrical Power System

choose a topic... Thermal Protection Main Propulsion System Separation System Orbital Man. System Reaction Control System Electrical Power System Environmental/Life Support Auxiliary Power Units Water Spray Boilers Hydraulic System Landing Gear System Caution and Warning Orbiter Lighting System Smoke Detection and... Payload Deployment... Payload Retention... Communications Avionics back to Shuttle Reference back to Orbiter Systems

Overview
The EPS consists of three subsystems: power reactant storage and distribution, fuel cell power plants, and electrical power distribution and control.

Power Reactant Storage and Distribution
Cryogenic hydrogen and oxygen are stored in specially-equipped tanks.

Fuel Cell Power Plants
The fuel cells are located under the payload bay area and in the forward portion of the orbiter's midfuselage.

Electrical Power Distribution and Control
The EPDC subsystem distributes 28-volt dc electrical power and generates and distributes 115-volt, three-phase, 400-hertz ac electrical power to all of the space shuttle systems' electrical equipment throughout all mission phases.