The NASA fuel cell upgrade program for the Space Shuttle orbiter

As part of NASA's overall efforts to improve the Space Shuttle operations, a program to upgrade the existing fuel cell powerplant has begun. The upgrade will involve replacing the alkaline fuel cell (AFC) system with a proton exchange membrane (PEM) fuel cell system, resulting in a much lower life cycle cost of the powerplant. The Shuttle Fuel Cell Upgrade plan of the JSC/LeRC/JPL team includes the following key elements: (1) systems analyses to assure compatibility/maximum utilization by shuttle of the best PEM fuel cell characteristics; (2) short stack testing of the leading PEM fuel cell contractors' hardware; (3) detailed task objective (DTO) flight experiment to verify PEM system water management and thermal management under zero-g operation; (4) A downselect to the best PEM system; and (5) development of the flight hardware powerplant system, including, of course, both the power and accessory subsystems. The planned success-oriented, four year effort is a coherent program to develop a 20 kW PEM fuel cell powerplant. The current major program tasks under way are short stack testing and systems analyses.