| Electrical Power
- The EPS consists of three subsystems: power reactant storage and
distribution, fuel cell power plants, and electrical power distribution
- 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.