8 September 2010 Contamination impact of station brush fire on cleanroom facilities
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Proceedings Volume 7794, Optical System Contamination: Effects, Measurements, and Control 2010; 779408 (2010); doi: 10.1117/12.860204
Event: SPIE Optical Engineering + Applications, 2010, San Diego, California, United States
Brush and forest fires, both naturally occurring and anthropogenic in origin, in proximity to space flight hardware processing facilities raise concerns about the threat of contamination resulting from airborne particulate and molecular components of smoke. Perceptions of the severity of the threat are possibly heightened by the high sensitivity of the human sense of smell to some components present in the smoke of burning vegetation. On August 26th, 2009, a brushfire broke out north of Pasadena, California, two miles from the Jet Propulsion Laboratory. The Station Fire destroyed over 160,000 acres, coming within a few hundred yards of JPL. Smoke concentrations on Lab were very heavy over several days. All Lab operations were halted, and measures were taken to protect personnel, critical hardware, and facilities. Evaluation of real-time cleanroom monitoring data, visual inspection of facilities, filter systems, and analysis of surface cleanliness samples revealed facility environments and hardware were minimally effected. Outside air quality easily exceeded Class Ten Million. Prefilters captured most large ash and soot; multi-stage filtration greatly minimized the impact on the HEPA/ULPA filters. Air quality in HEPA filtered spacecraft assembly cleanrooms remained within Class 10,000 specification throughout. Surface cleanliness was minimally affected, as large particles were effectively removed from the airstream, and sub-micron particles have extremely long settling rates. Approximate particulate fallout within facilities was 0.00011% area coverage/day compared to 0.00038% area coverage/day during normal operations. Deposition of condensable airborne components, as measured in real time, peaked at approximately 1.0 ng/cm2/day compared to 0.05 ng/cm2/day nominal.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Philip A. Carey, Brian K. Blakkolb, "Contamination impact of station brush fire on cleanroom facilities", Proc. SPIE 7794, Optical System Contamination: Effects, Measurements, and Control 2010, 779408 (8 September 2010); doi: 10.1117/12.860204; https://doi.org/10.1117/12.860204



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