Fight Fires…IN SPACE!

Welcome aboard the International Space Station!  You’ve already spent two and a half years getting ready for this moment and now you’re living the dream.  Every day, you spend your time running science experiments, doing routine maintenance on equipment, fixing things that break, and doing anything else you can to advance human exploration of space.

Then one day, something terrible happens.

It starts with a smell, a burning electrical odor, and then the next thing you know, the air around you looks hazy, like some mid-summer Houston smog has settled into the air.  Thanks to your excellent training, you know just what to do.  Instincts take over and you react swiftly.

The first thing you do is push a button that lets the entire crew and all the mission control centers around the world know that there is a fire aboard the space station.  Major news agencies will pick up on this within minutes.  Soon, the entire world will know that there’s an emergency on the station; the lives of the six crewmembers on board are now at risk.  You’ve now got everyone’s undivided attention.

With any luck, this is not like the solid fuel oxygen generator fire that occurred aboard MIR.  That was a fire that could not be put out with an extinguisher and was hot enough to melt metal.  You’re also hoping it has nothing to do with the 100% oxygen system that provides oxygen to experiments and emergency gas masks across the US segment.  Either of those situations could be catastrophic.

So you’re ready to face the worst, ready to charge in and be the hero, to save the day and ultimately grace the cover of the New York Times and Washington Post.  You’ll also be able to line up a pretty good book deal.  You look to the module to your left.   It’s full of smoke.  You need to save the lives of the crew and preserve this multi-billion dollar investment.  You charge in ready to save the day.

And you’ve killed yourself.  You just suffocated yourself with carbon monoxide or hydrogen cyanide.

You apparently didn’t build up enough of a survival instinct in your training to know that you shouldn’t go charging blindly in to save the day.

So let’s back up.  Once you’ve sounded the alarm, the first thing you do is get the whole crew together.  Make sure everyone is safe, accounted for, and you’re all on the same page with respect to what you need to do.  Since you see smoke, you know you’ll need a gas mask of some sort, there’s a couple of different varieties and you grab whatever is handy.  Time is of the essence here, you don’t want whatever small fire is burning to blossom into something that’ll destroy the station and kill everyone on-board.

Now, you’ve made sure everyone know what’s going on, everyone is safe, and you have a plan of attack.  You go back to where you think the problem is, with a friend of course since you’re not going about this alone.  The buddy system once again has its uses.  You see plenty of smoke, but thankfully or not,  no ball of fire.  Now, you realize you are in the middle of a module filled with dozens upon dozens of electronic components that could be the source of the fire.

Most of those components have been built with materials that are fire resistant, but in microgravity things get in unintended places, wires can rub against other things, a piece of flotsam can jam a motor, or any other series of unfortunate events could have happened to lead to this point.  But you’re still in the middle of this module, ready to do the hero’s work.  You just need to know where to do that work.

At last word comes from another crew member elsewhere on the station, he or she’s got some places for you to look.  She’s sitting at a laptop, in relative security, looking over station telemetry to try and find some clues to the fire’s location.  She tells you.  You grab your extinguisher, you fire it off, you’re the hero!

Except you just wasted the extinguisher because that’s not where the fire was.  And you went shooting across the module and damn near knocked yourself out because in microgravity discharging a fire extinguisher is like firing off a jetpack.  Next time remember to secure your feet.

Whee!

See, just because a piece of equipment is in a certain spot on the station, that doesn’t mean that its power source is in the same spot.  Imagine you’re at home and you’ve got a light plugged in on one end of a long room.  You have it plugged into an extension cord to reach an outlet on the other side of the room.  Now, say there’s a fire at the electrical outlet.  You’re first sign that something is wrong may be that the light goes out, but you’re not doing much good by using a fire extinguisher on the lamp.

Now, imagine there were a hundred such lamps in the room and one of them catches fire.  What’s the first thing you want to do?  If a toaster, radio, or something else starts to smoke, what’s the first thing you do?  You turn it off.  The same thing is true on the ISS; if you know what’s burning, you turn it off.  Now, with a hundred lamps connected to, say, twenty-five extension cords, it could take awhile to figure out the right one to turn off.  Just to be safe, we’ll shut off the power to the entire room.

The same philosophy applies to the space station and that is what you’re ready to do.  At this point, your helpful companion in the other module knows what piece of equipment might be on fire and where it’s plugged in.  You turn it off and if that doesn’t put out the fire, you’re finally ready to use the extinguisher.  You remember to secure your feet and you’re wearing a gas mask so that when you use the extinguisher you don’t kill yourself by surrounding yourself in a cloud of carbon dioxide.

U.S. fire extinguishers aboard the ISS don’t use water.  Instead, they release carbon dioxide.  Just removing oxygen that the fire needs to burn is good enough to put out the fire and maybe you’ve preserved some other expensive, delicate equipment that wouldn’t be able to handle being doused with water.  Russian fire extinguishers use a soapy foamy substance.  Those are not supposed to be used in U.S. modules.

Finally, the fire is out.  You are the hero you knew you could be.  Now you can close off the module and take a break while you and mission control put together a plan to clean up this mess.

Well done.

***

This post was inspired by a picture that future crew member and commander of ISS Chris Hadfield posted which provided a behind-the-scenes look at ISS fire response training.

Training astronauts - our instructors found a way to make a s... on Twitpic
We acquired that smoke machine about a decade ago in an attempt to create a more realistic environment for our fire response training while still meeting all of NASA’s stringent safety guidelines.  The smoke is harmless, but is realistic enough to create a sense of urgency in this training.  This is an approach we stole from the airline industry.  I spent five years as an Environmental Control and Life Support (ECLSS) instructor for ISS.  Fire response was one of the few things we trained the crew on that we hope they will never use.