Fire Suppression Tests Using a Handheld Water Mist Extinguisher Designed for the International Space Station

Abstract

ADA Technologies, Inc. has been developing a portable fire extinguisher for use in a microgravity environment for several years and has now started to transfer the technology to the specific platform of the International Space Station (ISS). ADA’s patent-pending device employs the principle of fine water mist, with advantages in compatibility, fire suppression efficiency, and minimal mass and volume for spacecraft use. The first ISS prototype is a scaled-up version of ADA’s earlier designs and is built around the same atomization technology. This larger extinguisher was first validated through droplet size measurements before being tested in a variety of fire test scenarios designed to represent worst-case situations aboard the ISS. ADA performed fire tests corresponding to an open cabin fire involving burning sheets of poly(methyl-methacrylate) (PMMA) and secondly, a heavily obstructed instrument rack fire where flames were ignited in remote zones of the enclosure. All open cabin fires were easily extinguished by a firefighter using the prototype. More than 90% of the rack fires were extinguished as well, but in two instances a flame survived the test, showing that further improvements to the design are recommended. Development of the hardware continues, with the goal of producing flight-qualified hardware in the next 18 months.