Slashdot Mirror

← Back to Stories (view on slashdot.org)

Fire Burns Differently In Space

Posted by timothy on from the half-as-long-twice-as-bright dept.

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."

44 of 146 comments (clear)

  1. There is no FIRE IN SPACE YOU DUMBA by Anonymous Coward · · Score: 5, Funny

    Oh my god what are you idiots d

    1. Re:There is no FIRE IN SPACE YOU DUMBA by dubsnipe · · Score: 4, Informative

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

    2. Re:There is no FIRE IN SPACE YOU DUMBA by show+me+altoids · · Score: 3, Interesting

      Yeah, but with no convection to carry away the combustion byproducts and bring in more oxygen, it is much more difficult.

      --
      I feel sorry for people that don't drink, because when they get up in the morning, that's as good as they're gonna feel
    3. Re:There is no FIRE IN SPACE YOU DUMBA by syousef · · Score: 5, Insightful

      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.

      --
      These posts express my own personal views, not those of my employer
    4. Re:There is no FIRE IN SPACE YOU DUMBA by necro81 · · Score: 4, Funny

      Which indicates there is a simple and obvious solution for extinguishing a fire in a spacecraft: just vent it out to space. The astronauts can just hold their breath, right?

    5. Re:There is no FIRE IN SPACE YOU DUMBA by Dan+East · · Score: 5, Interesting

      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.

      --
      Better known as 318230.
    6. Re:There is no FIRE IN SPACE YOU DUMBA by Anonymous Coward · · Score: 5, Informative

      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.

    7. Re:There is no FIRE IN SPACE YOU DUMBA by necro81 · · Score: 2

      While I appreciate your thorough analysis of my proposed solution, please keep in mind: I was joking!

    8. Re:There is no FIRE IN SPACE YOU DUMBA by MozeeToby · · Score: 5, Interesting

      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.

    9. Re:There is no FIRE IN SPACE YOU DUMBA by LanMan04 · · Score: 2, Informative

      People say "your blood will boil", but that's not actually what happens; the bubbles will be dissolved gasses coming out of solution.

      Um, that's the definition of boiling: Dissolved gasses coming out of solution. Can be induced by heating the fluid, lowering the atmospheric pressure, or both.

      --
      With the first link, the chain is forged.
    10. Re:There is no FIRE IN SPACE YOU DUMBA by Anonymous Coward · · Score: 3, Interesting

      There's still convection (heat/mass transfer by movement of fluid). Air still moves. The heated gases will expand and flow away from the fire, probably in a not entirely uniform way. And I would imagine that airflow from other sources (ventilators, moving objects) also exists. You don't have the expected convection from hot gases rising, that's why they're looking into how fire works in microgravity, because it works differently.

    11. Re:There is no FIRE IN SPACE YOU DUMBA by bberens · · Score: 3, Insightful

      I would be quite shocked to find that there wasn't constant airflow in the space station. It's not going to be a wind tunnel in there but there's going to be constant circulation from temperature control systems, whatever they use to filter the excess CO2 out of the air, etc.

      --
      Check out my lame java blog at www.javachopshop.com
    12. Re:There is no FIRE IN SPACE YOU DUMBA by AJH16 · · Score: 2

      Just out of curiosity, I wonder if a quick flush would in fact cause the bends if re-compression was prompt. People can operate at pretty low PSI (space suits are 4.3, atmospheric at sea level is 14.7). Would momentary decompression be a large risk if it was brief enough (my personal knowledge of DCS is only in regards to SCUBA which is obviously on the much higher pressure side of things). My understanding was that DCS normally takes a small period of time to develop that might give a window, though I would guess there would be other problems with high speed decompression. A better bet would probably be to do a halon flush with temporary breathing tanks though as it would avoid the whole issue of pressure change.

      --
      AJ Henderson
    13. Re:There is no FIRE IN SPACE YOU DUMBA by stealth_finger · · Score: 5, Funny

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

      Pretend the fire is a T-Rex.

      --
      Wanna buy a shirt?
      https://www.redbubble.com/people/stealthfinger/shop?asc=u
    14. Re:There is no FIRE IN SPACE YOU DUMBA by Lifyre · · Score: 4, Informative

      There is and it was the same with the space shuttles etc... if you lost something there was a good chance you could find it sucked up against in exhaust vent.

      --
      I'll meet you at the intersection of "Should be" and "Reality"
    15. Re:There is no FIRE IN SPACE YOU DUMBA by tmosley · · Score: 4, Informative

      Pretty sure boiling means the phase transition between liquid and gas.

    16. Re:There is no FIRE IN SPACE YOU DUMBA by Bob-taro · · Score: 4, Informative

      People say "your blood will boil", but that's not actually what happens; the bubbles will be dissolved gasses coming out of solution.

      Um, that's the definition of boiling: Dissolved gasses coming out of solution. Can be induced by heating the fluid, lowering the atmospheric pressure, or both.

      I'm not sure either of you are right. Boiling is when something changes state from liquid to gas. If you lower pressure enough, your blood (the water in it anyway) would literally boil at room temperature. However, decompression sickness - gases coming out of solution - is a different phenomenon that would probably happen first (at a higher pressure).

      --
      Prov 9:8 Do not rebuke mockers or they will hate you; rebuke the wise and they will love you.
    17. Re:There is no FIRE IN SPACE YOU DUMBA by gl4ss · · Score: 2

      I'm just going wtf is this news of 2011?
      http://en.wikipedia.org/wiki/Flame#Flames_in_microgravity

      I'm pretty sure I saw a similar picture in some book, magazine or something before 2000 too though. it's such an obvious experiment...

      --
      world was created 5 seconds before this post as it is.
    18. Re:There is no FIRE IN SPACE YOU DUMBA by mr1911 · · Score: 4, Insightful

      Okay, there's no GRAVITATIONAL convection, which is the dominant method that enables fresh oxygen to get to a fire in the earth's atmosphere.

      Don't tell that to fires. Fires often create their own convection due to a variety of factors.

      --
      This post comes with a double-your-money-back guarantee!
      Any offense taken to this post is at your sole discretion.
    19. Re:There is no FIRE IN SPACE YOU DUMBA by Anonymous Coward · · Score: 4, Interesting

      You require 3 things to keep a conventional fire going. Heat, fuel, and oxygen. The fire would not spread outwards unless there was fuel to burn as well. The same was that a campfire doesn't just keep spreading outwards away from the fire pit, since all the wood (fuel) is in the pit. Now if you were to spill a container of oil or other combustible liquid inside the space station, and then set it on fire. Now the fire could theoretically spread outwards in all directions as the liquid also spread outwards.

      On Earth, most fire suppression systems work on removing the heat and to some extent oxygen from the fire triangle. We use compressed CO2, which cools the area as it expands while also displacing some of the oxygen. Or by dousing it with a lot of water, which again cools the surrounding area and displaces some of the oxygen with steam.

      In a space station, I think the easiest way to stop a fire would be to vent the atmosphere since removing the oxygen would kill the fire right away. Though the downside is that humans also require oxygen so it'd kill any crew members in that section as well (Assuming they weren't in protective suits).

    20. Re:There is no FIRE IN SPACE YOU DUMBA by snowgirl · · Score: 2

      People say "your blood will boil", but that's not actually what happens; the bubbles will be dissolved gasses coming out of solution.

      Um, that's the definition of boiling: Dissolved gasses coming out of solution. Can be induced by heating the fluid, lowering the atmospheric pressure, or both.

      Boiling is actually the transition of the liquid into a gas, not gasses dissolved in the liquid coming out of solution. They look incredibly similar, but boiling can happen with a pure liquid, while dissolved gasses kind of by definition cannot come out of solution in a pure liquid. (Yes, the liquid turns to a gas and then kind of dissolves itself in the liquid, but it turns out that a gaseous form of a substance dissolved in the liquid form of that same substance is indistinguishable from the liquid itself.)

      So, on the first hand, the meaning of "boiling blood" means blood, wherein the liquid medium itself is actually turning into a gas, and thus generating gaseous bubbles, while blood with the gasses coming out of solution is itself not turning into a gas... (the later happening at lower temps, and higher pressures than the former.)

      --
      WARNING! This girl exceeds the MAXIMUM SAFE standards established by the FDA for BRATTINESS
    21. Re:There is no FIRE IN SPACE YOU DUMBA by The_Crisis · · Score: 3, Interesting

      So you get a bubble of low density CO2 around the fire, but not any movement

      That's correct, except for the parts where it's backwards and/or wrong. The heat given off as the product of combustion should increase the pressure of CO (and/or other products of combustion) (see: Charles' Law) which we are guessing would radiate away in all directions. That pressure increase should cause airflow from the area of higher pressure to the area of lower pressure (see: Wind). So (totally guessing/hypothesizing here) it seems to me that the heat generated as a result of combustion would increase the pressure and cause airflow away from the center of the combustion source which would prevent much if any O2-rich air from circulating, in effect choking itself out.

      --
      "It is a fine line between lazy and efficient."
    22. Re:There is no FIRE IN SPACE YOU DUMBA by blackanvil · · Score: 2

      "You're also making the assumption that you have enough stored gas (call it air) to repressurize the spacecraft." Since the pressure on a space station 1atm (according to wikipedia, at least), you could depressurize to 1/10th that, low enough to squelch combustion, by using a giant hefty bag out in space to hold it until the fire's out, then pump it back in. Ok, a giant heatproof hefty bag that can hold in 1/10th atm.

    23. Re:There is no FIRE IN SPACE YOU DUMBA by Anonymous Coward · · Score: 4, Interesting

      If I remember right: ISS, MIR... are/were very noisy because everything electronic has to be cooled by forced convection (fans). Without natural convection even a low powered circuit board that would easily dissipate the heat on Earth could eventually overheat in zero G as the heated air just sits there next to the components.

    24. Re:There is no FIRE IN SPACE YOU DUMBA by Guppy · · Score: 4, Interesting

      If you don't release pressure from your lungs as the ambient pressure decreases (when diving, by ascending), you'll do catastrophic damage to your lungs.

      Not holding your breath in a vacuum presents another problem though. Gas exchange in your lungs is a passive process, driven by concentration gradients. As the partial pressure of O2 in your alveoli drops to zero, the diffusion goes into reverse; blood passing through your lungs actually has its remaining oxygen content sucked out, causing you to black out almost instantly.

    25. Re:There is no FIRE IN SPACE YOU DUMBA by a+whoabot · · Score: 4, Insightful

      What you, grandparent, and great-grandparent have overlooked is just how inveterate motion is. Matter is always in motion above zero degrees Kelvin. The environment of the space station is going to be around room temperature, well above 0K, meaning lots of atomic motion. The molecules of this CO2 "bubble" will quickly disperse as they follow down their concentration gradient. Conversely, molecules of O2 will quickly reach the flame as they follow down their concentration gradient. The astronauts could stop oxygen from getting to the flame by sealing it, but not by staying very still.

    26. Re:There is no FIRE IN SPACE YOU DUMBA by camperdave · · Score: 3, Insightful

      Islands in the Sky by Arthur C. Clarke. A kid wins a contest and wins a trip to a space station as the prize. While on board he learns about microgravity environments, and due to an emergency, gets to travel to various other stations (a Zero G hospital, a communications station, a space hotel). A good, light read.

      --
      When our name is on the back of your car, we're behind you all the way!
    27. Re:There is no FIRE IN SPACE YOU DUMBA by syousef · · Score: 2

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

      Pretend the fire is a T-Rex.

      What ever happened to sending a urine bubble straight at it!? No imagination you guys!

      --
      These posts express my own personal views, not those of my employer
  2. Re:In case of fire: by ledow · · Score: 2

    Hold your breath first, though.

    Seriously, fire on board something like that would be about the scariest thing to deal with. With loss of air or something, you don't have time to panic but if the fires are burning at 100th their normal rate but are large enough to be pretty much unextinguishable, you've got a lot of fighting to do before you eventually end up burning.

    It'll get into every possible escape route and keep following you, it'll slowly suck up all fuel everywhere (can't just "move stuff away" if the *fire* is floating about), it'll be unpredictable and hard to tell when it's gone out, and it'll get into everything. And you're in a confined tin that you're relying on staying all in one piece to get back home at any point.

    The question is: why haven't we researched this more already?

  3. Hal Clements did a neat story on that by WillAdams · · Score: 2

    ``Fireproof'' I think it was, in his collection _Space Lash (formerly published as _Small Changes_)_.

    Looks like his theorization on the science was good (as it usually is).

    That book, and The Mad Scientists Club books made a huge impact in my childhood.

    --
    Sphinx of black quartz, judge my vow.
  4. Why? by Anonymous Coward · · Score: 2, Insightful

    Why does everything have to be some stupid ass acronym?

    1. Re:Why? by N0Man74 · · Score: 5, Funny

      Are you referring to the WDEHTBSSAA effect?

  5. Obligatory by mattie_p · · Score: 5, Funny

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

  6. Re:Don't Yank our Funding by bmo · · Score: 5, Insightful

    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

  7. What's the big deal? by smooth+wombat · · Score: 4, Funny

    We all know what to do if a fire breaks out in a spaceship or station. Didn't you people watch Red Planet?

    You grab your fire extinguisher, point it at the fire, release the locking pin, pull the handle and get propelled across the room due to no gravity holding you in place and the fire retardant being ejected from the nozzle

    Come on you geeks, get with the program!

    --
    We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
  8. Re:In case of fire: by 2fuf · · Score: 5, Informative

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

  9. Re:Don't Yank our Funding by Tekfactory · · Score: 2

    I don't know if this is still part of it, but somewhere years back I read that NASA was planning on experimenting with different types of water spraying nozzels on the ISS, IIRC there was a micro-nozzle that sprayed a mist using substantially less water than a regular nozzle and the mist put out fires more effectively than gallons of water in a narrow stream.

    Those interested can Google Fine Water Mist and Fire, they did some microgravity testing on a KC-135.

  10. Re:Don't Yank our Funding by Anonymous Coward · · Score: 3, Funny

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

    We all know what a yurt is, but the types that you are referring this question to will laugh at you thinking you can't live inside a yogurt...

  11. Ob "benefits here on earth" debunking by Rogerborg · · Score: 4, Funny

    If you're trapped in a free-falling elevator, whether it's on fire or not is probably the least (or briefest) of your worries.

    --
    If you were blocking sigs, you wouldn't have to read this.
  12. Re:Don't Yank our Funding by JasterBobaMereel · · Score: 3, Insightful

    One day sir, you may tax it. - Faraday's reply to William Gladstone, then British Chancellor of the Exchequer (minister of finance), when asked of the practical value of electricity (1850)

    --
    Puteulanus fenestra mortis
  13. Decommissioned Shuttles.... by TommyGunnRX · · Score: 2

    If the DoD was involved they could just launch a decommissioned space shuttle and set it ablaze... Then when it falls back to earth market it as a chance to win a piece of the shuttle! Talk about a great PR move!

  14. Re:finally! by camperdave · · Score: 2

    one has to ask .. after all this time:"how many billions dollars does it need to extinguish a fire in zero gravity?" sheesh, after discovering fire thousands of years ago after climbing down from trees, one would expect this would be like .. duh .. the first experiment one would do in outerspace?

    I think fire was discovered long before we climbed down from the trees. In fact, it may have been an impetus for climbing down from the tree.

    --
    When our name is on the back of your car, we're behind you all the way!
  15. Re:Don't Yank our Funding by mcgrew · · Score: 4, Interesting

    You do know that we went from the founding of this country to 1913 without an income tax, right?

    There was no income tax, but there was taxation. My grandfather was 17 years old in 1913. Few know (as far as I can tell) that when the federal income tax was enacted, only the rich were taxed.

    The tax was to pay for a war, which is pretty much where most of your federal income taxes go anyway.

    Without income taxes you would not have the interstate highway system (which, incidentally, was built by a Republican administration). I was a little kid when they started building it, and I remember that getting from St Louis to Springfield was a three or four hour drive, vs the hour and a half (or less) on the interstate.

    Without federal income taxes you would not have the hoover dam. Americans would not have landed on the moon. America wouldn't have been able to reap the financial winfall of rebuilding Europe after WWII.

    The only downside to taxes is that you're a greedy selfish money grubber. Since you seem to be a tea party type, you probably consider yourself to be a Christian (hint: there are no Christians in the Tea Party, it is definitely against everything Jesus taught), you might want to open that bible you like to thump and read Matthew 22:21.

    --
    Free Martian Whores!
  16. Re:This definitely provides relevant research by amRadioHed · · Score: 2

    When one considers that less than 2% of the Sun is something other than Hydrogen and Helium, and Oxygen being only another chunk of that 2% with other elements having their chunks of that respective small percentage, that quote gives us considerable insight into why the Sun and other stars burn for as long as we believe they do.

    Two problems with what you said. First, the sun has gravity. It has a lot of gravity, and so hot gases do rise due to convection, as they do on earth. That said, the sun doesn't burn. The heat is generated from nuclear fusion in its core, and that is the reason why stars last so long.

    --
    We hope your rules and wisdom choke you / Now we are one in everlasting peace