Abstract View
Quantifying Smoke Detector Performance for Spacecraft Applications
CLAIRE FORTENBERRY, Marit Meyer, Thomas Cleary, David Urban, Gary Ruff, Universities Space Research Association
Abstract Number: 508
Working Group: Combustion
Abstract
Smoke detection presents a unique challenge for the future of human space flight. In a confined cabin where fire suppression and escape options are limited, early fire detection is critical to ensure crew survival and safety. Several factors challenge early fire detection in spacecraft. In microgravity, smoke plumes are unaffected by buoyancy and therefore do not rise as they would on Earth, so smoke detectors are commonly placed within air intakes rather than on ceilings. Additionally, high particle filtration rates typical of spacecraft life support systems may extend a smoke detector’s time to alarm, allowing more time for a fire to progress and for toxic combustion products to accumulate in the spacecraft cabin. While different particle-based smoke detector designs have been used in spacecraft throughout the years, each design has distinct advantages and disadvantages. A critical factor in detector performance is particle size, motivating recent studies to characterize particles from the combustion of various spacecraft-relevant materials. These studies demonstrated that smoke particle size widely varies depending on fuel composition and combustion characteristics, further complicating the selection of an optimal detector design.
We present results from laboratory studies to compare the performance of different smoke detector designs with various types of aerosol. Smoldering lamp wick and a soot generator were used to generate aerosol representative of oxidative pyrolysis and flaming combustion, respectively. Diethylhexyl sebacate and mineral oil reference aerosols enabled evaluation of detector performance based on particle sizes. Because quantified relationships between ionization and light obscuration/extinction detectors depended heavily on particle size distributions, these results will inform spacecraft detector design and help predict performance under different potential spacecraft fire scenarios. Finally, we will discuss the applicability of these findings to the development of detectors for future long-duration and lunar missions.