BASS-M stands for Burning and Suppression of Solids – Milliken and is part of a series of BASS experiments that investigate how solid materials burn without the presence of gravity which is of use in physics but also in spacecraft engineering and fire protection. The BASS-M experiment looks at flame-retardant cotton fabrics to determine how well they resist burning in microgravity. This can be used in the development of flame-retardant textiles for use on Earth and in space.
The BASS-M experiment will put the hypothesis that materials in microgravity burn as well (if not better) than in normal gravity to the test given identical environmental parameters (pressure, oxygen concentration, temperature).
Also, different air flow rates will be employed to resemble forced convection in microgravity or free fall conditions on Earth. A total of ten differently treated textiles will be tested and each textile’s ability to self-extinguish will be compared against tests conducted on the ground. BASS uses an upward burning test which mimics the worst-case geometry for flammability on Earth which also allows for a comparison of upward burning on Earth and in space.
BASS-M delivers to ISS 44 textile samples already integrated with igniter wires – four samples of 11 different sample types, one being an untreated control. Each sample consists of a small portion of untreated textile that interfaces with the igniter to provide a start-point for the burning process so that the flames of the untreated sample directly impinge on the treated portion of the textile.
A high speed camera will capture the burning process and sensors will be used to keep track of the burning process, flame shape, flow speed, flame spread rate and flame dynamics such as oscillations and pulsations. The critical observations for the extinction are flame dynamics just prior to extinction for incorporation in models.
BASS-M uses BASS and SPICE (Smoke Point In Co-flow Experiment) hardware set up in the Microgravity Science Glovebox. Hosted within the assembly is a fan and an anemometer to measure the flow rate which can be adjusted between 5 and 50 centimeters per second. A radiometer quantitatively measures the flame output. Each test is expected to take around one minute from ignition to full extinction.