Burn baby burn. Today, we use water to put out fires. But what if we could use it for the opposite effect? Astronaut researchers on the International Space Station are experimenting with water that can start a fire. It's called supercritical water and it might offer benefits such as clean-burning municipal waste disposal and improved saltwater purification.
Water becomes supercritical when it is compressed at 217 times the air pressure found at sea level and heated above 703.4 degrees Fahrenheit. At that point, the water is not liquid, solid or gas – it's more of a liquid-like gas. When this supercritical water mixes with organic material, oxidation occurs. The supercritical water burns the organic material, but without the pesky flames.
The burning process with this transformed water breaks down unwanted materials without the risk of dangerous byproducts. It's mostly just carbon dioxide and water. Studying supercritical water in space without the complications of gravity, researchers can better understand how to use its burning properties and how to control leftover salt that can damage pipes and tanks. Check out the video, from ScienceAtNASA, above.