Air Date: Week of January 31, 2003

Living on Earth’s Cynthia Graber reports on research taking place in space about how best to extinguish indoor fires.

Transcript

CURWOOD: Just ahead, a deadly campaign against a deadly disease. First, this Note on Emerging Science from Cynthia Graber.

[THEME MUSIC]

GRABER: Astronauts on the current space shuttle mission are testing a new firefighting system that battles blazes with a fine-water mist instead of harmful chemicals or large quantities of water. Bromine-based compounds had been used to attack fires chemically, especially in places like computer rooms where water would cause damage. But they’ve been banned because they damage the ozone layer. Aside from being non-polluting and less damaging, water mist prevents fires from expanding in two ways. It removes heat, and as it evaporates, it replaces oxygen that would otherwise fuel the fire.

The mist system is being tested in space because it’s easier to observe the interaction between a flame and water in low gravity. On Earth, lighter, hotter air rises, creating air currents that pull in oxygen and feed the fire. But in the micro-gravity of the shuttle, these air currents are greatly reduced, making it easier to isolate the effect of the water mist on a flame.

In the shuttle experiment, a water mist is released onto a flame that burns inside a tube. Scientists hope these tests will help them determine the best water concentration and water droplet size needed to suppress fires with the least damage.

That’s this week’s Note on Emerging Science. I’m Cynthia Graber.

CURWOOD: And you’re listening to Living on Earth.

[MUSIC FILL: Ry Cooder “Drume Negrita” Mambo Sinuendo, Nonesuch (2003)]