Smart chemical sensor systems for fire detection and environmental monitoring in spacecraft

A fire in a spacecraft or habitat supporting NASA's exploration mission could jeopardize the system, mission, and/or crew. Further, an understanding of the environment during standard operations as well as after a fire is important for both astronaut health and for monitoring of hazardous conditions. This paper describes the status of gaseous sensors to provide early warning of fires, eliminate false alarms, and provide environmental information. These gaseous sensors are miniaturized arrays of smart chemical sensors that accurately detect fire signature gases such as carbon monoxide and carbon dioxide, as well as other species such as oxygen. The approach we take can significantly reduce the size, mass, and power consumption of sensing technology allowing more strategic placement, extended operation, and improving overall awareness of the environment. In particular, this paper describes: 1) Maturation of the core chemical sensor technology and associated smart hardware; 2) Expansion of the sensor array for species of interest such as hydrogen cyanide and hydrogen chloride; and 3) Sensor system test results for two application environments. It is concluded that smart, multiparameter, microsensor based systems can serve as multiuse technology for a range of applications including fire detection and environmental monitoring, and can complement other sensor technologies.