All of us have seen films which feature a fire inside the depths of space, the majority notably within the 2013 movie Gravity in which – alongside George Clooney smouldering away – viewers saw a fire break out upon their space station.
However, how could a fire really behave in microgravity? NASA scientists, fortunately, have been pondering that themselves for a long time.
Researchers, since 2009, onboard the ISS (International Space Station) have actively been performing experiment Flame Extinguishment Experiment (FLEX) that sought to figure out how fire will behave in space and, most importantly, how to put it out.
As you light a candle, it’ll form a classic teardrop shape. But, that only is due to gravity. As the oxygen is consumed by fire, the hotter air will rise and cooler un-combusted air will sink to the bottom. However, without gravity, there isn’t any separation between heavier and lighter air, therefore the fire burns in every direction equally, and causes a slow-burning world of combustion.
Oddly, Flame Extinguishment Experiment discovered that combustion has the ability to occur without any visible flames.
Look at this DNews episode that displays wonderful and even odder demonstrations of fire inside space.