Space Shuttle Will Test Green Firefighting
Astronauts on this month’s space shuttle mission tested a new fire fighting system that battles blazes with a fine water mist or fog, instead of using harmful chemicals or large quantities of water that damage property.
To fine tune the designs of their fire fighting systems, two companies are flying a commercial experiment on the STS-107 flight. The study will be managed by the National Aeronautics and Space Administration’s (NASA) Space Product Development Program.
“The fire-fighting industry is in search of a new tool that doesn’t use dangerous chemicals or douse fires with huge quantities of water that cause extensive property damage,” said Mark Nall, director of the Space Product Development Program at NASA’s Marshall Space Flight Center in Huntsville. “By flying this commercial experiment on the STS-107 Columbia mission, NASA is helping industry design a cost effective, environmentally friendly system for putting out fires.”
Until recently, halons, bromine-based compounds, were used to attack fires, particularly in places like computer rooms, aircraft, and document storage rooms where water sprinklers were inappropriate. In 1998, the production of these chemicals was banned worldwide because they damage Earth’s protective ozone layer.
“We are working to find an acceptable replacement for halons, and water mist appears to be the best choice,” said Dr. Thomas McKinnon, lead scientist for the research at The Center for Commercial Applications of Combustion in Space (CCACS) at the Colorado School of Mines.
“The shuttle tests use a humidifier like device to produce water drops about 20 microns in size,” explained Dr. Angel Abbud-Madrid, the project scientist at the NASA Commercial Space Center. “That’s about one-tenth the diameter of a human hair, as opposed to drops produced by conventional sprinklers that are about one millimeter, or 50 times the size of our droplets.”
The water mist research team is working with MicroCool Inc., a division of Nortec Industries Inc., and Fogco Systems Inc. These companies manufacture water mist systems for putting out fires and for other purposes, such as outdoor cooling and industrial humidification.
“Firefighters in Denver and at the Arvada Fire Training and Research Center have tested our ultra-fine mist nozzles,” said Mike Lemche, general manager of MicroCool. “The cooling effect of this mist removes one of the key components of fire – heat.”
Since the fog removes heat and replaces oxygen as the water evaporates, it prevents the fire from expanding and starting new fires.
Gary Wintering, president of Fogco, said his company will use information from the STS-107 experiment to fine-tune their designs of fire-fighting systems. Prior combustion experiments have shown that space is the ideal place to study the physics of fire.
On Earth, gravity causes lighter, hotter air to rise, creating air currents that make it difficult to study combustion processes. In microgravity–the low gravity inside the shuttle orbiting Earth–air currents are reduced or eliminated, making it easier for scientists to observe how water interacts with a flame to put it out.
“The shuttle experiment will help us determine the optimum water concentration and water droplet size needed to suppress fires,” said Abbud-Madrid. “We have learned from short tests on NASA’s KC-135 reduced gravity aircraft and inside drop towers that water mists take one-tenth the water of traditional sprinklers to extinguish a flame.”
Provided by theEnvironmental News Service.
