Fire Safety Implications of Preliminary Results from Saffire IV and V Experiments on Large Scale Spacecraft Fires



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50th International Conference on Environmental Systems


The spread and growth of flames over large solid fuel samples and their effect on the pressurized spacecraft were studied inside Cygnus spacecraft while in orbit after departing the International Space Station. These experiments were developed by NASA�s Advanced Exploration Systems Division in the Human Exploration and Operations Mission Directorate. The ignited materials consisted of poly-methyl methacrylate (PMMA), cotton fabric and a cotton/fiberglass fabric blend. The samples were all 40 cm wide and with various lengths ranging from 18 cm for the PMMA samples to 50 cm for the fabrics. The overall results from these tests and their impact on the spacecraft are presented with emphasis on the fire safety implications of the results. The experiments included, a post-fire cleanup system, vehicle internal volume measurements, and transport of acid gases (HCl and HF). Measurements included video images, flame spread rate, flame temperatures and radiant heat output; energy release through oxygen calorimetry; distributed measurements of CO2 concentration and temperature at six locations in the spacecraft; CO2, CO, O2, HF and HCl concentrations; vehicle pressurized volume; and aerosol concentrations. Details of the flame growth and spread are discussed in other papers as are details of the post-fire cleanup system performance. The fire events had a measurable impact on the vehicle pressure, temperature, and carbon dioxide concentration. However, despite having heat release rates up to 10 kW, the average vehicle conditions did not rise to unacceptable levels. The combined results of the experiments provide significant new understanding of the impact of sample and flow duct height on flame spread and growth in addition to an improved perspective of the impact of a fire event on a spacecraft.


David Urban, NASA
Gary Ruff, NASA
Paul Ferkul, USRA
John Easton, USRA
Jay Owens, USRA
Sandra Olson, NASA
Marit Meyer, NASA
Claire Fortenberry, Universities Space Research Association
John Brooker, NASA
John Graf, NASA
Michael Casteel, Jacobs
Grunde Jomaas, The University of Edinburgh
Balazs Toth, ESA
Christian Eigenbrod, University of Bremen, ZARM
James T'Ien, CWRU
Ya-Ting Liao, Case Western Reserve University
Carlos Fernandez-Pello, University of California, Berkeley
Florian Meyer, ZARM
Guillaume Legros, CNRS-Orleans
Augustin Guibaud, University College London
Nikolay Smirnov, Moscow Lomonosov State University
Osamu Fujita, Hokkaido University
ICES509: Fire Safety in Spacecraft and Enclosed Habitats
The 50th International Conference on Environmental Systems was held virtually on 12 July 2021 through 14 July 2021.


fire, microgravity, cygnus