Fire Burns Differently In Space

New submitter black6host writes with this interesting snippet from Space.com: "NASA is playing with fire on the International Space Station — literally. Since March 2009, the space agency's Flame Extinguishment Experiment, or FLEX, has conducted more than 200 tests to better understand how fire behaves in microgravity, which is still not well understood. The research could lead to improved fire suppression systems aboard future spaceships, and it could also have practical benefits here on Earth, scientists said."

Comments

There is no FIRE IN SPACE YOU DUMBA

[Anonymous Coward]

Oh my god what are you idiots d

Re:There is no FIRE IN SPACE YOU DUMBA

[syousef]

Well, as long as there is oxygen around, things should combust.

Sure, in a crude way you're right and there are a lot of electricals and combustibles on spacecraft. But HOW does it burn when there is no UP? We're so use to hot air rising that our everyday ideas of how to deal with a fire, like get down low, will not work in space. These are ideas that save lives here but are of no use if a fire were to break out. We can only develop new ideas if we get some direct experimental experience. Also it may lead to an ability to harness the differences inherent in a zero g process for industrial/manufacturing processes (but I'm just speculating here). This is worthwhile basic science.

Re:There is no FIRE IN SPACE YOU DUMBA

[Dan East]

I would think that the worst possible thing (or best possible thing, from Invader Zim's viewpoint) that could happen with a fire in zero G is air flow / turbulence. If there isn't any movement of air, then the oxygen surrounding the fire is consumed and the fire burns very slowly. Since convection currents are a product of gravity, they don't occur in zero G so no fresh O2 is sucked into the fire for combustion as it does here on earth. So I would think anywhere there is an air vent blowing air, or even people just moving around in the environment, you'd have blowtorch like fire forming where the air is disturbed. I bet you could literally see the turbulence in the air as wisps of flame. Kind of disturbing to think of.
An example of this is in a swimming pool. Have you noticed that if you hold very still in motionless, cold water, that you will begin to feel warmer, but as soon as you move it feels cold again (and no, I'm not talking about heating the pool with your pee). That is because the molecules closest to your body heat up, and since they aren't flowing and being replaced by colder molecules, only conduction takes heat away. It's sort of the same principle with fire in zero-g, where the fuel has consumed the oxygen near it (and it is also surrounded by combustion byproducts as well), so as long as fresh air isn't wafted into it, combustion almost grinds to a halt.

Re:There is no FIRE IN SPACE YOU DUMBA

[Anonymous Coward]

That's a nice notion. However, there's a wicked problem with the bends. People say "your blood will boil", but that's not actually what happens; the bubbles will be dissolved gasses coming out of solution. even if you go with a straight oxygen environment (which we learned was a "bad idea" in the Apollo program), the oxygen dissolved in the astronaut's blood will come out of solution. Unfortunately, it won't dissolve again very quickly, which will leave you with bubbles in bad places, like the brain and lungs.

You're also making the assumption that you have enough stored gas (call it air) to repressurize the spacecraft. Even if you live through the depressurization and repressurization, you haven't addressed the source of the fire, which will likely re-ignite. As long as spacecraft are small, gold-plated things, designing to current fire specs is a given. However, as they evolve into large vehicles, designing fire-proofing into everythign will become less and less feasible. People will want to bring clothes and food and shit like that.

The other major thing to be considered is that while droplets behave differently, we also haven't looked at explosive combustion. I suspect it will be very similar. However, we might find that it's very different. Right now we cover military pilots in polyaramids, and accept that paying passengers are probably going to die in a flash fire. The assumption behind the flight suit is that the pilot's on an O2 mask, and so the lungs will be protected. Flash fires might behave very differently, and fire is a complex, complex beast.

I've lived through a fire in an airplane, and it's scarry as fuck. Fortuantely, the aerospace community is very aware of it and designs against it.

Re:There is no FIRE IN SPACE YOU DUMBA

[MozeeToby]

It's not as totally and completely insane as it sounds. Generally, people will recover from exposure to vacuum on their own if the exposure is short (less than 30s) and with surprisingly minor injuries if exposure is less than 90s. And that's without training and a warning of what's going to happen, given proper planning and equipment I suspect you could push the survival rate to the high 90%s, maybe even to two 9's.

Given the choice between burning to death in inescapable zero-g fire and an automated 15 second emergency purge, with a quick re-pressurization system, O2 masks for quicker recovery, and the ability to manage air pressure afterwards to treat the bends... personally, I'd give it a shot. The only real question mark is if the source of the fire has been taken care of. If it's an ongoing short you might find yourself in the same boat you started in, but even that could be addressed by re-pressurizing the spacecraft with nitrogen and relying on O2 masks for the crew until everything is straightened out.

Re:There is no FIRE IN SPACE YOU DUMBA

[stealth_finger]

There goes stop drop and roll, would be more like Stop and remain motionless.

Pretend the fire is a T-Rex.

Obligatory

[mattie_p]

Screaming is different, too, from what I've heard. Or did I?

Re:Don't Yank our Funding

[bmo]

but I'd be curious if anyone has any idea what the practical benefits of this experiment could be.

Without basic science, you don't get applied science.

I sure wish the know-nothing "hurr why study fruit flies? hurr!" idiots would fucking understand this.

But no. They get in their cars and drive, use computers, talk on cellphones, dance at the club to kilowatts of audio, eat, drink, and be merry and then decry the amount of money we spend on basic science to make all that possible.

Don't like money spent on basic science? Go live in a yurt.

--
BMO

Re:Why?

[N0Man74]

Are you referring to the WDEHTBSSAA effect?

Re:In case of fire:

[2fuf]

relevant: http://www.youtube.com/watch?v=iSqOqRACxUM (fire at the MIR station)