In space, no one can hear you scream "Fire." Not that it'd matter, as few people could recognize a microgravity fire anyway. This means space firefighting gear needs to be special. NASA is on it.
First, a primer. Fire in microgravity isn't the flickering kind that happened when you set the house ablaze with your chemistry set as a kid. It's actually spherical (see image), and spreads around space stations, space shuttles or special projects like Orion faster than you can say "Hey, I didn't know NASA let us smoke on the space shuttle?"
NASA astronaut Jerry Linenger got to experience space fire first hand in 1997, when an oxygen candle aboard Mir caught fire and filled the space station with smoke. "I did not expect smoke to spread so quickly," Linenger said in an interview with Discovery. "(It) was about 10 times faster than I would expect a fire to spread on a space station."
So NASA, not wanting to roast its astronauts alive, has continued to research and fine tune a variety of next generation space fire-fighting systems. A few prototypes work well, but they're messy, coating the fire spheres and pretty much everything else in the vicinity with a fine mist, fog or "water foam" made up of a non-toxic oxygen-nitrogen mix.
The special extinguishers have actually been around for about a decade, but only recently has NASA noticed them, funded them, and started testing in microgravity experiments. Previously, NASA's main advice for astronauts in a dangerous fire-related situation was "abandon ship" (seriously)— an option which would be, obviously unavailable to an Orion crew on a Mars or Moon mission.
I say bring on the mess so long as the "Go Directly to Earth" autopilot button stays dry. If I were in a tin can millions of miles from home, I'd take soggy, foamy clothes over the other option any day of the week. Better messy than dead, says I. [MSNBC]