Fire signatures of spacecraft materials: Gases and particulates

The primary goal of this research is to create a database of fire signatures for practical spacecraft materials in a new combustion facility and to provide recommendations for the development of improved fire sensors for future space exploration. During a fire, foams and plastics can generate three types of residues: condensables, light gases, and particulates (soots). The residues were characterized by gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). These analyses were performed as a function of oxygen occurrence, temperature, and convective flow direction relative to the normal gravitational vector. Among the four polymers studied in this work, forced convective flow direction has a great impact upon particulate yield. Variation of light gases with temperature and different atmospheres turn out to be more convoluted. Particulates can be used as fire signature for most of the materials; nevertheless no single species serves as a reliable indicator for any given material.