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The Saffire Experiment Will Study Real Fires in Microgravity

Fire goes orbital.
Flames on Earth. Image: Luc Viatour

Playing with fire in space sounds like a really bad idea, but that's exactly what NASA intends to do with its upcoming Spacecraft Fire Experiment (Saffire) mission.

This combustible research project is slated for launch in 2016, and will be activated at a distance from the International Space Station to avoid, you know, setting our only orbital outpost ablaze. The details of the mission are covered in a new video released on Friday by NASA's Glenn Research Center.

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NASA is partnering with Orbital Sciences for the project—the same company that was devastated by a launchpad explosion last year. Unlike SpaceX, Orbital uses expendable rockets and spacecraft, meaning that their flagship Cygnus capsule isn't built to survive re-entry. Where SpaceX's Dragon capsules can be theoretically be used multiple times, the Cygnus is a one-time-only spacecraft.

Expendable vehicles aren't as efficient as reusable ones, but they happen to be perfect for lighting fires in space. Once the Cygnus has delivered its payload of supplies to the ISS, it can be released back into orbit with the Saffire experiment still onboard.

The hardware for the test will include several fabrics that will be ignited inside the capsule, and monitored by cameras and other instruments. The data from the experiment will then be relayed back to Earth, and the Cygnus will be free to immolate itself in the atmosphere, destroying everything it contains in the process.

You might be wondering why NASA wants to spark a bunch of space fires in the first place. The answer is that scientists know next to nothing about how fire works in microgravity—or how to prevent and extinguish it. Astronauts are trained to handle spacecraft fires, but they would still be in serious trouble if a real one broke out on the ISS, because flames behave completely differently in outer space than they do on Earth.

Fire on Earth compared to fire in microgravity. Image: NASA

For one thing, in microgravity, flames take the shape of Nintendo-style fireballs rather than the familiar teardrop structure we are familiar with on Earth. Accordingly, fires can expand in any direction, and can burn at colder temperatures in space than on our planet. These bizarre, unpredictable properties have prevented astronauts from experimenting much with combustion in orbit for safety reasons, and so we simply don't know a lot about space fire.

"Currently, most flammability data for materials in microgravity is obtained during short-duration, drop-tower tests with small sample sizes," Orbital VP and former astronaut Carl Walz told Reuters.

"There is very little data on large-scale material flammability in low-gravity environments," he continued. "Gathering this type of data will enable NASA to enhance safe operations of new space vehicles that are being designed for long-duration travel to the Moon, asteroids, and other destinations."

In other words, next year, NASA will delight astrophiliac pyromaniacs around the world by setting fire to materials inside an orbiting capsule, before the capsule itself burns up in the atmosphere. Smokey the Bear is going to need a space age makeover.