Amazing 'cool-burning flames' discovered on the International Space Station could result in cleaner, more efficient engines here on Earth
Thanks to a remarkable discovery on board the International Space Station, scientists and engineers here on Earth may soon be able to produce cool-burning engines, which will not only cleaner, but more fuel efficient. What was this discovery? Cool-burning flames.
The International Space Station is a remarkable achievement, as it's kept a continuous human presence in low-Earth orbit for nearly 14 years. However, the true value of the ISS is its role as a science laboratory, due to the continuous zero-g environment it provides. Hundreds of science experiments have been conducted on the station during its time in orbit - many to test the effects of zero-g on plants, animals and us, for the continued success of human space exploration, but there have also been plenty that were designed to take advantage of the station's environment to develop advances for us back here on Earth as well.
A recent experiment sent up to the space station by researchers at the University of California, San Diego - the Flame Extinguishment Experiment (or FLEX) - sought to study how flames behave in zero-g, to increase safety on board space missions. In the process of conducting the experiment, though, the crew on the station and the scientists on the ground discovered something amazing.
According to a news release from the UC-San Diego Jacobs School of Engineering:
During the experiments, researchers ignited large droplets of heptane fuel. At first, it looked like the flames had extinguished themselves, just as they would have on earth. But sensors showed that the heptane was still burning, although the resulting cool flames were invisible to the naked eye. The cool flames occurred in a wide range of environments, including air similar to the earth’s atmosphere and atmospheres diluted with nitrogen, carbon dioxide and helium. The resulting combustion reaction creates toxic products, such as carbon monoxide and formaldehyde, which in turn burn off.
The video below, shot during the FLEX tests on the station, shows the fuel ignition and the resulting cool-burning flame that persists afterwards, and the cloud of vapour that forms after the cool flame finally extinguishes:
"We observed something that we didn't think could exist," said Prof. Forman Williams, who was the lead researcher for FLEX, according to the news release.
If these principles were applied here on Earth, it could lead to the development of engines that burn at cooler temperatures, and consume not only the fuel but also some of the flammable (and potentially harmful) byproducts in the process. This would make these engines cleaner, more efficient, and even easier to work on, as they would not produce as much waste heat in their operation.
Given that this was an accidental discovery, NASA and the UC - San Diego scientists are only at the beginning of this research, and more experiments are being planned to specifically investigate this phenomena, for future trips up to the International Space Station.