Skylab Experiment M479 Zero Gravity Flammability

Flammability under conditions of weightlessness was investigated in Skylab 4. Thirty-seven tests using six materials were successfully carried out to learn more about how a flame acts in the absence of convection. Specific objectives were to note the extent of surface flame propagation and flash-over to adjacent materials, rates of surface and bulk flame propagation, self-extinguishment, and extinguishment by both vacuum and water spray. All tests were performed and all hardware functioned properly, although an operational oversight caused the water in the supply tank to be less than the minimum required pressure. Burning rates were significantly reduced as anticipated from earlier aircraft tests. Some reduction of total burning was also noted. The surface burn was not followed by continued inward burning as typically experienced on earth although some one-g tests at extremely low pressures have partially reproduced this condition. Ignition and extinguishment also appear to be similar to one-g. Smoke patterns were also noted. This can be of value in studying Brownian movement of solids in gases under conditions of weightlessness.