Smoke Characterization and Feasibility of the Moment Method for Spacecraft Fire Detection
Jiann C. Yang, Thomas G. Cleary, George W. Mulholland, Marit Meyer, Victoria Bryg, D L. Urban, Zeng-guang Yuan, Gary A. Ruff
The Smoke Aerosol Measurement Experiment (SAME) has been conducted twice by NASA and provided the first real-time aerosol data in a spacecraft micro-gravity environment. Flight experiment results have recently been analyzed with respect to comparable ground-based experiment results. The ground tests included a Scanning Mobility Particle Sizer Spectrometer (SMPS) reference instrument for measuring particle size distributions of the smoke produced from overheating five common spacecraft materials. Repeatable sample surface temperatures were obtained with SAME ground-based hardware and measurements were taken with the aerosol instruments returned from the International Space Station (ISS) consisting of a commercial smoke detector, several aerosol instruments which measure moments of the particle size distribution, and a thermal precipitator for collecting smoke particles for Transmission Electron Microscopy (TEM). Moment averages from the particle number concentration (zeroth moment), the diameter concentration (first moment), and the mass concentration (third moment) allowed calculation of the count mean diameter of the smoke particles and the diameter of average mass. Additional size distribution information including geometric mean diameter and geometric standard deviations can be calculated if the particle size distribution is assumed to be lognormal. Both un-aged and aged smoke particle size distributions from SMPS ground experiments were analyzed to determine the validity of the lognormal assumption. Comparisons are made between flight experiment particle size distribution statistics generated by moment calculations and microscopy particle size distributions from TEM grids which have been returned to Earth.
, Cleary, T.
, Mulholland, G.
, Meyer, M.
, Bryg, V.
, Urban, D.
, Yuan, Z.
and Ruff, G.
Smoke Characterization and Feasibility of the Moment Method for Spacecraft Fire Detection, Aerosol Science and Technology, [online], https://doi.org/10.1080/02786826.2015.1025124
(Accessed February 27, 2024)