Here on Earth we can use water to put out most fires, both because it helps prevent easy contact with oxygen in the air and reduces heat via rapid evaporation. But astronaut researchers on board the International Space Station (ISS) are working to develop a special kind of water that actually makes things burn — except without the flame part.
Called supercritical water, this exotic substance is neither a solid, liquid, nor gas but rather a “liquid-like gas.” Made by compressing ordinary liquid water to 217 times the air pressure found at sea level and heating it above 703 degrees Fahrenheit (373 degrees Celsius), supercritical water rapidly oxidizes any organic substance it comes in contact with — in other words, it burns it.
One specific use for supercritical water is to aid in waste disposal, both in space and on Earth. Burning via supercritical water breaks down harmful substances in liquid waste but doesn’t produce particularly dangerous byproducts — mostly just water and carbon dioxide, which can easily be filtered out.
he unique microgravity environment of the ISS allows for investigation of better supercritical water applications, especially the control of residual salt that can corrode metal pipes and storage tanks. Check out the ScienceCast video above from Science@NASA for more on this latest high-flying research!