NASA has been conducting experiments to learn how fire grows and spreads in space. The most recent experiment was Saffire IV, and it had longer and stronger flames inside a Northrop Grumman Cygnus cargo spacecraft than in past tests. NASA wants to know how flames grow and spread in space, so it can help protect astronauts as they travel to the moon and beyond.
Just as the other experiments in the series, Saffire VI was conducted aboard a Cygnus cargo spacecraft after it had finished its primary resupply mission and was a safe distance away from the ISS. There was a significant difference in this experiment compared to the others in the series. With Saffire VI, after two material burns, a carbon dioxide scrubber and a smoke eater were used to remove particulate and carbon monoxide from the environment.
A sensor to monitor combustion gases and the smoke eater filter are prototypes of what would be used on the Orion spacecraft. NASA says that it loaded the Saffire VI mission with more diagnostic equipment to see how effectively it can detect fires, measure combustion products, and evaluate future fire response and cleanup technologies. The experiment burned a sample of SIBAL cloth, which is a composite made up of 75% cotton and 25% fiberglass.
In the video below, the bright sparkles left after the flame passes are glowing char on the surface of the cloth. The first three experiments in the series had limited-size fires and examined ignition and spread over similar materials. Results show the flame spread quickly and achieved a steady size and burn rate, unlike here on Earth, where flames tend to continue to grow. The team also learned that the size of the spacecraft had more effect on fire in space than anticipated.
The big goal of the Saffire project is to understand fire behavior in space so safety measures can be developed to deal with fire emergencies when astronauts don’t have the option to exit the spacecraft or quickly return to earth. Two additional experiments in the series are scheduled with one in October 2020 and another in March 2021.