Burning and Suppression of Solids

Burning and Suppression of Solids (BASS) examines the burning and extinction characteristics of a wide variety of fuel samples in microgravityThe condition of perceived weightlessness created when an object is in free fall, for example when an object is in orbital motion. Microgravity alters many observable phenomena within the physical and life sciences, allowing scientists to study things in ways not possible on Earth. The International Space Station provides access to a persistent microgravity environment.. BASS will guide strategies for extinguishing accidental fires in microgravity, and results will contribute to the combustion computational models used in the design of fire detection and suppression systems in microgravity and on Earth.

BASS utilizes slightly modified Smoke Point In Co-flow Experiment (SPICE) hardware within the Microgravity Science Glovebox (MSG) for observations of burning solid materials onboard the ISSInternational Space Station.

Many sample configurations can be used: flat, solid spheres, candles within tubes, etc. Concurrent flow spread rate, limiting flame length, and other combustion characteristics can be measured using images. The cotton-fiberglass fabric blend Solid Inflammability Boundary at Low-Speeds (SIBAL) fuel has been used. Other materials that have been burned include Nomex, Ultem, Polymethylmethacrylate (PMMA), and wax-saturated fiberglass fabric. For some of these tests, the nitrogen suppressant system is engaged at a gradually increasing level until extinction is reached.

The important experimental observations from BASS with respect to the burning process include flame shape and appearance as a function of flow speed, flame spread rate (how fast the flame develops), and flame dynamics (pulsations, oscillations, etc.). With respect to extinction, the critical observations and data are the time to extinction as a function of fuel geometry, the nitrogen flow rate, and the flame distance from the nozzle.