Increased demands for more reliable circuit protection and power control in manned space craft electrical systems have resulted in a vigorous exploratory research program to develop a totally new systems concept of protection and control using solid-state logic in conjunction with either solid-state or electromechanical power switching.
The electrical power system currently used in manned space craft is patterned after those used in aircraft. It should be noted that, in many cases, the electrical system, in even our most modern aircraft, could stand a critical re-evaluation