Final answer:
Open-Circuit SCBA refers to a system used by divers and firefighters to carry breathable air for use in environments without safe ambient air. These systems benefit from aerospace technology, including lightweight materials and advanced electronics, to enhance safety and functionality.
Step-by-step explanation:
An Open-Circuit SCBA (Self-Contained Breathing Apparatus) is a device used by divers and firefighters to carry breathable air in a high-pressure tank. Scuba divers use SCBA to breathe underwater, taking advantage of the compressibility of gases which allows a large volume of air to be stored in small containers. The technology behind SCBA has benefited from aerospace advancements, including the utilization of lightweight materials and electronics initially developed by NASA for rockets. These developments have improved the safety and efficiency of SCBA units for life-saving applications.