2014-10-222014-10-222014-07-13978-0-692-38220-2ICES-2014-179http://hdl.handle.net/2346/59738Tucson, ArizonaSandra L. Olson, NASA John H. Glenn Research Center at Lewis Field, USAHarold Beeson, NASA Johnson Space Center- White Sands Test Facility, USAA. Carlos Fernandez-Pello, University of California at Berkeley, USAThe 44th International Conference on Environmental Systems was held in Tuscon, Arizona, USA on 13 July 2014 through 17 July 2014.Repeated Test 1 extinction tests near the upward flammability limit are expected to follow a Poisson process trend. This Poisson process trend suggests that rather than define a ULOI and MOC (which requires two limits to be determined), it might be better to define a single upward limit as being where 1/e (where e (=~2.7183) is the characteristic time of the normalized Poisson process) of the materials burn, or, rounding, where approximately 1/3 of the samples fail the test (and burn). Recognizing that spacecraft atmospheres will not bound the entire oxygen-pressure parameter space, but actually lie along the normoxic atmosphere control band, we can focus the materials flammability testing along this normoxic band. A Normoxic Upward Limiting Pressure (NULP) is defined that determines the minimum safe total pressure for a material within the constant partial pressure control band. Then, increasing this pressure limit by a factor of safety, we can define the material as being safe to use at the NULP + SF (where SF is on the order of 10 kPa, based on existing flammability data). It is recommended that the thickest material to be tested with the current Test 1 igniter should be 3 mm thick (1/8”) to avoid the problem of differentiating between an ignition limit and a true flammability limit.application/pdfengPresentation