How to Handle a Fire Onboard a Generation Ship?

[Strato Incendus]

Okay, since I’m tired of being stuck at even just planning the midpoint catastrophe in my sci-fi story set on a generation ship — after all the scenarios I have already considered, but which ultimately wouldn’t have made sense, as the people on this forum were kind enough to point out to me — let’s finally go with the most mundane, but potentially most effective one:

A fire breaking out on board the spaceship.

The beauty of this kind of catastrophe as a tool is its flexibility: A fire could break out anywhere for a multitude of reasons, and it can spread easily. Given the size of the ship at almost 3 km, if I need the fire to be in multiple places that are a certain distance apart from each other, I need to come up with an explanation why the fire would either cover the distance in between, or why several fires would break out in several places independently of each other. (Unless of course they have a common reason that can cause fires even in distant places.)

For this purpose, I still haven’t quite let go of the idea of a small dust particle piercing tiny holes in the ship hull as it is being turned around to brake; this particle, depending on its trajectory, could damage a bunch of different kinds of equipment — and people — on board the ship. We’ve already established that a human being getting pierced by such a particle at 0.125 c would probably be ripped to shreds, despite the small size of the particle.

But of course, the dust particle is just one of many potential reasons for fire breaking out. Given my ship has a nuclear-fusion drive, I would assume fire would be particularly likely anywhere where the fuel takes hydrogen form (if this is the case anywhere). Of course, the fuel itself isn’t stored in hydrogen form, but as regular water that double-acts as a radiation shield to the front and back of the ship.


So the question is:
1) How does fire behave in zero gravity vs. in an environment of centrifugal gravity (=on the ring sections of the ship)?
2) What safety technology would the ship have against cases like this (maybe starting with whatever the ISS has for preventing fires on board)?
3) What levels of casualties would you expect, assuming a bunch of people are sent in to extinguish the fire as quickly as possible?

 

[Flyboy]

1. Fire in zero G does weird things. NASA has studied it for some time to better understand how it behaves, and the biggest takeaway is that you need airflow for it to spread. There’s no density-induced drafts like on a planet, so if it’s a small fire, it might just burn itself out from oxygen starvation. The only thing I can think of other than an existing airflow to spread the fire would be to have s linear fuel source, akin to the classic “gunpowder trail” you see in movies and tv shows.

As for behavior under pseudogravity such as in a centrifuge, I would expect it to behave fairly normally. Flames would move in the direction of the local “up”.

2. Fire prevention in a spacecraft is pretty straightforward: minimize the amount of easily ignitable materials aboard, and use a standard nitrogen-oxygen atmosphere. If it’s in a centrifuge section, a typical water-based fire sprinkler system will generally suffice, with specialized equipment for areas like electrical rooms.

3. Casualties? What casualties? Look at the history of shipboard firefighting in the US Navy since 1940 onwards. The vast majority of casualties are from either being cut off from an escape route or from ordinance cooking off, usually both at the same time. If you have a way in/out, you stand a very high chance of survival. The most recent high-profile shipboard fire I can recall is the USS Bonhomme Richard, which suffered a catastrophic fire while in port in 2020. Despite the firefight running for four days and consuming a fairly sizable portion of the ship, no one was even severely injured. Couple cases of smoke inhalation and exhaustion on the first day, but that was it. Everyone made it out safely.

As far as jumping on the fire quickly, yep, that’s the best strategy. Everyone on a Navy ship is a firefighter at need, from the greenest sailor to the captain. Fire is the greatest enemy of a sailor.

 

[Hornbein]

Part of the reason the Zumwalt destroyers flopped was that they didn't carry enough sailors to fight fires and so forth.

 

[Nik_2213]

In zero-g areas, the fire triangle soon breaks down. Halt air-supply, partially vent to quench. If to vacuum tank rather than 'Deep & Dark', the 'vented' atmosphere maybe recovered by pumping...
In spun-hab zones, beyond super-messy sprinklers, there are neat mister systems. Also, fit those automatic 'monitors' that triangulate warehouse fires using infra-red and squirt them.

Each buys time to close section isolation doors -- Double, forming 'foyer', so can be air-lock, so no dying tragically / heroically on wrong side etc-- and tackle the problem.

Multiple simultaneous outbreaks ? I'd suspect arson, criminal intent...,

The 'turn-over' vulnerability ? Cease acceleration, disperse dust-cloud ahead to form shield before doing the flip.
D'uh, if ship was coasting for a long, long time after initial boost, would they not deploy such a 'shield cloud' already ??

 

[DaveC426913]

The 'turn-over' vulnerability ? Cease acceleration, disperse dust-cloud ahead to form shield before doing the flip.
D'uh, if ship was coasting for a long, long time after initial boost, would they not deploy such a 'shield cloud' already ??

This had just never occurred to me. It's brilliant.

 

[Vanadium 50]

Part of the reason the Zumwalt destroyers flopped was that they didn't carry enough sailors to fight fires and so forth.

Well, maybe, if someone asked you for 10 reasons why it flopped and you already had 9, you might use this as the 10th. But multi-billion dollar overruns, and a lack of a mission is where I would start. The fact that there is no ammo for the guns would be right up there too.

The best model for "fire in space" is probably the fire on the submarine USS Bonefish. That fire began underwater.

 

[russ_watters]

Not enough sailors is a Navy reason, not a real reason: "how can a captain command so few sailors?" See also; "where is the paint locker?"

 

[Vanadium 50]

The Zumwalts were a terrible idea from the get-go. "It's a floor wax! It's a dessert topping!"

Some wanted a stealth ship. Some wanted a ship to do shore bombardment. These are reasonable things to want. But putting them together makes no sense. Stealth does little good when you can see where the shells are coming from.

Further, for what an Elmo costs, you could have 2-4 Burkes. There are mighty few situations where you wouldn't be happier with the latter.

I would also argue that multiple new technologies on the same vessel is asking for trouble. Nuclear submarines showed the way to do that. Start with a Tang. Add a reactor and you get the Nautilus. Switch to a sodium reactor and you get the Seawolf. OK, bad idea. Go back, and now you have a Skate. Add an Albacore hull and a 2nd reactor, and you have the Triton. Too big - keep the hull, drop the 2nd reactor, and shrink it, and you have a Skipjack.

The Bonefish was a miracle. I think three officers and men died, but they almost lost the boat. A fire starts underwater and you are in big, big trouble. Space is likely worse, since you can't get the crew on deck. You could possibly open the affected compartment to space, but it would not have helped in this case, as the root cause was electrical. As soon as you repressurized, the fire would have restarted.

 

[Strato Incendus]

Thanks a lot for your many ideas! :)

On the one hand, I’m glad to hear the world is already as safe as it is right now in terms of fire prevention.
On the other hand, I’m really running out of potential disasters to throw at my fictional crew. Which is why my story has been stuck on this issue for… almost two years now?

You would think that being surrounded by the deadliest thing imaginable — space — would make it easy to inflict mass casualties on a ship, in order to up the stakes of the plot for the survivors.

But as I’ve stated before: All disasters I can think of that would have the potential to do serious damage to the ship would probably be big enough to destroy the entire ship right away (such as micro-meteors, perhaps even just a comparatively small speckle of dust).

I guess other sci-fi stories might have the luxury of just tossing a battle with some random alien species in there, whenever they seriously want to damage a given ship and its crew. But my story doesn’t feature any explicit mention of intelligent aliens — only extraterrestrial primordial wildlife on the target planet on the one hand; and allusions to a species far more advanced than our own on the other hand (to incorporate the “tic-tac” UAPs you’ve probably heard about on the news last year).

The 'turn-over' vulnerability ? Cease acceleration, disperse dust-cloud ahead to form shield before doing the flip.
D'uh, if ship was coasting for a long, long time after initial boost, would they not deploy such a 'shield cloud' already ??

This had just never occurred to me. It's brilliant.

I once proposed to fire a salvo of the deflector lasers in advance, right before initiating the procedure that turns the ship around to brake. The reception to that idea here on the forums was sceptical, as far as I recall. How would the disperse dust-cloud be different / better to address this issue? In particular, if the deploy the dust cloud right after ending the first acceleration phase / right at the beginning of the coasting phase?

 

[DaveC426913]

I once proposed to fire a salvo of the deflector lasers in advance, right before initiating the procedure that turns the ship around to brake. The reception to that idea here on the forums was sceptical, as far as I recall. How would the disperse dust-cloud be different / better to address this issue?

Well, it's simple, passive, multi-tasking and uses cheap inert material. You simply spew the cloud and forget it. Its efficacy depends only on its reach and its density.

With lasers, you ... what? zap individual particles? How do you see them? How many can you zap in the window between when you catch sight of them and when they will impact? How much power does that use?

In particular, if the deploy the dust cloud right after ending the first acceleration phase / right at the beginning of the coasting phase?

The dust cloud is continuous of course. It will stay there as long as you stay on course. Another advantage.

Something I might do is keep the cloud compact, don't let it disperse too much over time so as to lose effectiveness.

Here's how: spewing the cloud out front of ship will cause it to continually increase its distance (and, critically, volume), until it is too rarefied to do much good (unless you re-do it).

So:

1. Have the ship come up to cruising speed.
2. Disperse the cloud with virtually zero pressure (i.e. low delta-v), so that it does not expand appreciably more than the ship's cross-section over a good long time.
3. Now, hit the retros for a sec. Then forward again. This causes the ship to drop back a few kilometres (or a few thousand kilometres) and then match speeds again.

The upshot is that the cloud remains at the same distance in front of the ship - it does not continually get farther ahead - and more importantly - does not disperse more than necessary.

 

[ShadowKraz]

I like the comparison of a space ship on fire with a submarine on fire; it holds water, so to speak. On that note, if I am recalling correctly, there is at least one fire suppression chem that when released into the sub's air at one part per billion (I think, it may be higher or lower) will suppress a fire almost instantly. BUT, at two parts per billion also terminally suppresses the sailors' life cycles. It has two advantages over using water in that a flammable liquid won't float and keep burning plus it doesn't affect mechanical or electrical systems.

 

[Nik_2213]

Can you manage with a lower oxygen proportion ? Even a few percent less makes the 'Fire Triangle' harder to close.

 

[Vanadium 50]

Um...he;s not trying to prevent a fire. He's trying to write about one.

 

[DaveC426913]

Um...he;s not trying to prevent a fire. He's trying to write about one.

True. But he does want to write a plausible story for his audience.

And if his audience is smart enough to know it's a no-brainer that lowering the O2 level prevents fire catastrophes then he should probably get out ahead of that.

 

[Vanadium 50]

Well, I don't think he's writing a textbook.

However, the US legal limit for unprotexted low oxygen (ODH 0) is 19.5%. So "we'll just cut back on the O2" doesn't work, at least is the audience is, as you put it, "smart enough".

 

[DaveC426913]

Um...he;s not trying to write an OSHA manual. He's trying to write a science fiction novel.

 

[ShadowKraz]

Well, I don't think he's writing a textbook.

True but since fire suppression systems exist in the here and now, they are more than likely to exist in the future and especially for a mission as important and expensive as this one. The readers are probably likely to know about them as well.
Better to hash this out now and account for it not functioning, possibly by having multiple systems fail due to the puncture(s), than to have critics (you know they love to point out fallacies and gross errors) drag the novels through the muck.

 

[Strato Incendus]

I like the comparison of a space ship on fire with a submarine on fire; it holds water, so to speak. On that note, if I am recalling correctly, there is at least one fire suppression chem that when released into the sub's air at one part per billion (I think, it may be higher or lower) will suppress a fire almost instantly. BUT, at two parts per billion also terminally suppresses the sailors' life cycles. It has two advantages over using water in that a flammable liquid won't float and keep burning plus it doesn't affect mechanical or electrical systems.

This sounds promising, because to me as a layman, this reads like a safety system with a tiny margin of error — therefore, one that could easily be thrown off balance.

Am I understanding this correctly, that if just one part too many (per billion) of this suppression chemical gets released into the air of, say, a ring section, it will not only suppress the fire, but also kill any human beings within that section?

That would of course beg the question of why they would rely on something so dangerous, even if it may be effective as long as it works perfectly. As the others have established, they’d still have the option of going for more mundane solutions, like water sprinklers.

Speaking of water, I once asked here on the forums whether it’s possible to drown in space, if one gets surrounded by water in zero g. The water should form a bubble which, depending on the amount of water that leaks out / gets sprayed somewhere in order to combat a fire, could enclose one or several human beings, without leaving them a way of simply “swimming out of the bubble” as long as they’re in zero g, right?

True but since fire suppression systems exist in the here and now, they are more than likely to exist in the future and especially for a mission as important and expensive as this one. The readers are probably likely to know about them as well.
Better to hash this out now and account for it not functioning, possibly by having multiple systems fail due to the puncture(s), than to have critics (you know they love to point out fallacies and gross errors) drag the novels through the muck.

That’s precisely the reason why I’m trying to plan all of this. I’m not the type of writer who plots out everything before he writes the very first chapter — there’s already a bunch of stuff written, and the word count is already way past what’s usual in sci-fi, where word counts tend to be lower on average than in fantasy. I’m currently stuck with an unfinished book at a word count where others would have completed two.

Probably because, while remaining stuck at the plotting question of what kind of catastrophe exactly should be happening at the midpoint, I’ve still continued writing other chapters — which gave me time to flesh out side characters etc. I’ll probably have to cut a lot of that stuff again later on, but who knows.

The point is: I can beat myself up for not making any progress on the number of connected chapters (i.e., the number of chapters you can read from beginning to end). But ultimately, getting stuck in the drafting process is just a symptom of a persistent fault in the plotting process.

If I go back and think about all the potential disasters we’ve already considered (micro-meteors, viruses, black holes, solar flares from some nearby or rogue star — too bad there isn’t any other one in the constellation where the ship is headed — and ultimately, the dust speckle that pierces the ship hull), I could have written down complete scenes for all of these scenarios. But ultimately, I would have had to cut all of them again, because none of these scenarios would have made sense. So it’s better to have experts point that out in advance, both to save time and to not have to throw away scenes I may have come to like once I’ve already written them.

 

[DaveC426913]

This sounds promising, because to me as a layman, this reads like a safety system with a tiny margin of error — therefore, one that could easily be thrown off balance.

In a book I read many moons ago, a Mars station got hit with a freak meteor shower that punctured their inflatable dome. Emergency procedures for a dome puncture were to crank up the oxygen (not air) so that occupants could breathe for those few critical seconds while the lower pressure stopped the dome from ripping further.

Just floating the idea that, while a lower oxygen mix might be the norm for a ship, there are certainly emergency conditions where the norm is not the best tactic.

 

[BillTre]

Real disasters often involve more than one thing failing at once. Any one of them could be survivable, but the combination results in failures.
This approach means your failure (or initial failure) does not have to have such big effects.
Its more like the power of an interacting set of three things going wrong together.
Might be dramatic.

 

[DaveC426913]

Real disasters often involve more than one thing failing at once. Any one of them could be survivable, but the combination results in failures.

This is where I was going with the emergency oxygen infusion.
In the story, the consequence of that momentary emergency was unforseen and pernicious and caused a mystery that lasted till the climax.

When the puncture occurred, the medical doctor was in the middle of doling out the vitamin-C doses. He had the entire supply open to the air. In the following weeks, the protagonist got very sick and thought he was dying. They connected the dots just in time. The colony's emergency oxygen influx had degraded all their vitamin-C rations. Turns out he simply had scurvy!

 

[Vanadium 50]

if I am recalling correctly, there is at least one fire suppression chem that when released into the sub's air at one part per billion (I think, it may be higher or lower) will suppress a fire almost instantly. BUT, at two parts per billion also terminally suppresses the sailors' life

I find this hard to believe.

(1) How do you safely handle tanks of this stuff? How do you manufacture it? Its roughly as dangerous as dimethyl mercury.

(2) What is its mechanism of function? It can't cool, it can't displace oxygen and there isn't enough of it to affect fuel. Halon, which has properties like you describe, removes hydrogen from plasma - but it takes a few percent to do this.

(3) Is thus highly reactive or is it inert? In the first case, why isn't it consumed immediately, and if the latter how does it work at ppb levels?

(4) Mixing of low concentration gasses is imperfect. Argon weighs only 30% more than air and it pools on the floor. How do you keep toxic levels of this stuff from pooling in certain places.

While one is allowed to use magic in science fiction, this stuff raises the "huh?" flag.

 

[ShadowKraz]

I find this hard to believe.

(1) How do you safely handle tanks of this stuff? How do you manufacture it? Its roughly as dangerous as dimethyl mercury.

(2) What is its mechanism of function? It can't cool, it can't displace oxygen and there isn't enough of it to affect fuel. Halon, which has properties like you describe, removes hydrogen from plasma - but it takes a few percent to do this.

(3) Is thus highly reactive or is it inert? In the first case, why isn't it consumed immediately, and if the latter how does it work at ppb levels?

(4) Mixing of low concentration gasses is imperfect. Argon weighs only 30% more than air and it pools on the floor. How do you keep toxic levels of this stuff from pooling in certain places.

While one is allowed to use magic in science fiction, this stuff raises the "huh?" flag.

I know this sounds lame but ... I learned about it in the late 80s - early 90s and my source is deceased. What else I remember is that it was based on or involved bromine; that is solid as we were discussing bromine at the time and this was given as an example of bromine's importance. How and what I heard about it prompted me assume it was an actively deployed system on U.S. submarines, not an experimental design. If it is, or was, not an actively deployed system, then obviously my assumption was incorrect.

Having said that, the point of my comment was that there could be a system akin to this on board the spaceship that would not have undesired effects on other, essential systems.
The question, however, of whether or not this or a similar system exists at this point in time is irrelevant to this discussion. It could plausibly exist at the time the stories take place.

 

[Strato Incendus]

Real disasters often involve more than one thing failing at once. Any one of them could be survivable, but the combination results in failures.
This approach means your failure (or initial failure) does not have to have such big effects.
Its more like the power of an interacting set of three things going wrong together.
Might be dramatic.

Yes, failures at multiple levels is usually how major catastrophes happen, so that was indeed what I was planning to use.

The question to solve first, though, is: If you were to design a fire-prevention system for a spaceship, would you actually choose to rely on such a chemical (assuming it's bromine) that would be extremely effective at one part per million but deadly to humans at two parts per million? It sounds to me as a layman as if I really needed a good reason for water sprinklers etc. being insufficient before I can justify the people in my world taking this risk.

 

[ShadowKraz]

I did a cursory search for submarine fire suppression systems and nothing mentions bromine. I now assume that the system that was described to me was experimental and did not make it past that phase. Vanadium 50 probably raised the very concerns that killed the system. If they hadn't, I wouldn't have made the search, so kudos to them.
But... there do seem to be other systems along the same lines in place that don't pose the same risks.
My thinking is that yes, it would be a good idea to come up with an alternative to a water-based suppression system because water and electricity or electronics (even when not powered) don't mix well. It would also be handy for avoiding metal fatigue ( very real concern for a spaceship's hull) due to extreme temperature gradients.
An alternative that would allow water-based systems, at least in some parts of the ship, is to borrow an idea from Heinlein's 'Orphans of the Sky", something he calls 'statics'. If you're not familiar with the story, his idea was having control systems that are more or less comparable to room temp superconductors but that do not rely on electricity or moving parts. I think he was trying to overcome the problem of maintaining a system if the skills and knowledge needed were lost during the voyage; something that did occur before the novel opens.

 

[Rive]

How does fire behave in zero gravity vs. in an environment of centrifugal gravity (=on the ring sections of the ship)?

I would not fill up the engine compartment and zero gravity parts permanently with air ( at least, not with a breathable mix) to start with: so apart from accidentally having some hot parts, only the rings would be affected => there would be gravity so all those references about ships and other enclosed systems which are already here are valid.

With the additional possibility of venting to space I would say it's not really a fitting disaster. Mentioning all the preparations and drills is fine, but as an actual disaster it feels very limited.

I’m really running out of potential disasters to throw at my fictional crew.

Boredom

Ps.: ... and that's actually no joke - seafarer's boredom has a pretty long literature

 

[Hornbein]

Boredom

Ps.: ... and that's actually no joke - seafarer's boredom has a pretty long literature

Sailors fought that with song, dance, theater, tales, and carving scrimshaw.

 

[Rive]

Sailors fought that with song, dance, theater, tales, and carving scrimshaw.

Also by infighting, bullying, depression, suicide, mutiny...

 

[Hornbein]

Also by infighting, bullying, depression, suicide, mutiny...

Winston Churchill made a proposal to the navy. The response was that this was against the traditions of the British Navy. "I'll tell you the traditions of the British navy," rejoined the Prime Minister. "Rum, buggery, and the lash!"

 

[BWV]

Jumping in late, but concur that fire is unlikely and lame - deliberate sabotage is much better as a plot device - you get the drama of the disaster, can believably make the disaster do whatever you want because it’s sabotage , plus the drama of the saboteur(s) which can either tie into the main plot or just be a staging device

 

[Strato Incendus]

Jumping in late, but concur that fire is unlikely and lame - deliberate sabotage is much better as a plot device - you get the drama of the disaster, can believably make the disaster do whatever you want because it’s sabotage , plus the drama of the saboteur(s) which can either tie into the main plot or just be a staging device

Thanks for your suggestion! :) Given that the fire explanation doesn’t seem to be working either, because the failsafes would probably be too reliable, I was indeed thinking of intentional sabotage at this very moment, too — or rather: a terrorist cell forming on board the ship.

There are two problems with this, though:

1) I’m already making plenty of use of intentional sabotage in the backstory / potential second prequel, by pointing to a bunch of technology that has been destroyed by the youth rebel organisation Turning Point. Among others, they destroyed the artificial wombs the ship originally departed from Earth with. (Artificial wombs would undermine one of the core ethical dilemmas of the main book, but it would seem irresponsible for the ship not to have them at the start, and intentional sabotage is a better way to get rid of them than to pretend the ship designers had simply forgotten about them, or that every last one of them had been destroyed by some accident.)
The rebels in the first main book are now facing the issue of constantly being compared to Turning Point, for objecting to certain aspects of the mission. If I add actual terrorism or major sabotage that leads to casualties into the first main book, it will feel like a lot of repetition, compared to the backstory / potential prequel.

2) A terrorist group that needs to be fought would indeed get closer to the idea of military conscription, for which this midpoint disaster is an allegory, since it’s mostly male crew members that die in it. However, if we’re just talking about a small terrorist / saboteur cell, one would first expect professional security officers to handle this, rather than requiring every male crew member to stop the saboteurs. Conversely, if the group of defectors sabotaging the ship is already so large that you require a bunch of people to stop them, that would in turn also make it easier for people to defect and become part of the saboteurs, since they’d know they’re not alone in their opposition to the ship’s establishment. The rebellion / mutiny however is only supposed to really kick into full armed conflict in the 5th and last act.

Meanwhile, the midpoint disaster is the initial catalyser for the first batch of people to defect from the mission in the first place — on the one hand, a few of the male survivors of the catastrophe who feel like the ship’s command treats them like cannon fodder; on the other hand, the women who are expected to refill the ranks and make up for the casualties lost (not filling the ranks themselves, but with their offspring).

Thus, if there’s already a saboteur cell prior to the midpoint disaster, that disaster can’t really up the stakes anymore. It’s a bit like the inciting incident usually shouldn’t be the result of the protagonist’s actions yet, but something that comes crashing into their life and gets them to start acting in a protagonist-worthy way from then on.

 

[BWV]

Malaysia Flight 370 (pilot murder / suicide)

Also rogue AI (thinking after reading alot of Ian Banks) that large spaceship crews are dumb. Probably need at most a few humans to tell the computers what to do and then a crew to see after passengers. Its another stupid SF convention that spaceships are manned like WW1 dreadnaughts

 

[Strato Incendus]

Malaysia Flight 370 (pilot murder / suicide)

There is indeed plenty of suicide in my story already - enough people develop psychiatric conditions over the course of this long journey through the lonely void of space that takes over a century. Some of them question the purpose and ethics of the mission itself in the process. The pilots aren't among them, though, or at least never take these considerations this far.

Even if they did, though: A pilot getting incapacitated for some reason (they don't even have to die) sounds a lot less critical for a spaceship during the coasting phase than it would be for the pilot of a plane. ;) The officer overseeing the deflector system (space debris approaches too fast for a human to manually shoot down, of course) would have been a more critical position on the bridge; however, with the dust-cloud solution that was proposed earlier in this thread, even a constant surveillance of some laser-based deflector system might no longer be necessary.

Also rogue AI (thinking after reading alot of Ian Banks) that large spaceship crews are dumb. Probably need at most a few humans to tell the computers what to do and then a crew to see after passengers. Its another stupid SF convention that spaceships are manned like WW1 dreadnaughts

True, but given that my ship's commander is the main antagonist, I think the AI that is the ship's computer will be much more intimidating if it is on the commander's side (having been programmed to value human survival over everything else) than if it turned into A.L.I.E. from The 100...

 

[DaveC426913]

Thanks for your suggestion! :) Given that the fire explanation doesn’t seem to be working either, because the failsafes would probably be too reliable..

I think this pendulum may have swung a little to far the other way.

Consider the implication of what you're saying, above: that a fire disaster aboard a spaceship seems actually implausible.

How did we get from "a fire is by far the worst conceivable crisis aboard an enclosed vessel" to "a fire is so unlikely to become a crisis that it will seem lame"?

You want to make a fire unlame and raise its terror factor in the mind of the reader? Remind them of the unspeakable events aboard its sister ship, back in Earth orbit, where a chemical fire broke out during the night shift when most of the crew were ... blah blah ... and it started close to the yadda yadda compartment, and the emergency protocol was to vent the chambers to hard vacuum**. Some crew still remember the frozen bodies floating outside the port holes that took days to be retrieved, etc, etc.

**anybody remember this from the original Battlestar Galactica? They were under attack by the Cylons, and fires broke out in the docking bays, preventing the fighters from taking off or landing. The ship was a sitting duck and the fighters were getting poicked like bugs. The Admiral did the only thing he could - he vented the docking bays, putting out the fires - and simultaneously signing the death warrants of dozens or hundreds of crew.

Fires in enclosed spaces are horrific. Ain't nobody gonna call a fire 'lame' after you paint a scene like that...

 

[pinball1970]

Okay, since I’m tired of being stuck at even just planning the midpoint catastrophe in my sci-fi story set on a generation ship — after all the scenarios I have already considered, but which ultimately wouldn’t have made sense, as the people on this forum were kind enough to point out to me — let’s finally go with the most mundane, but potentially most effective one:

A fire breaking out on board the spaceship.

The beauty of this kind of catastrophe as a tool is its flexibility: A fire could break out anywhere for a multitude of reasons, and it can spread easily. Given the size of the ship at almost 3 km, if I need the fire to be in multiple places that are a certain distance apart from each other, I need to come up with an explanation why the fire would either cover the distance in between, or why several fires would break out in several places independently of each other. (Unless of course they have a common reason that can cause fires even in distant places.)

For this purpose, I still haven’t quite let go of the idea of a small dust particle piercing tiny holes in the ship hull as it is being turned around to brake; this particle, depending on its trajectory, could damage a bunch of different kinds of equipment — and people — on board the ship. We’ve already established that a human being getting pierced by such a particle at 0.125 c would probably be ripped to shreds, despite the small size of the particle.

But of course, the dust particle is just one of many potential reasons for fire breaking out. Given my ship has a nuclear-fusion drive, I would assume fire would be particularly likely anywhere where the fuel takes hydrogen form (if this is the case anywhere). Of course, the fuel itself isn’t stored in hydrogen form, but as regular water that double-acts as a radiation shield to the front and back of the ship.


So the question is:
1) How does fire behave in zero gravity vs. in an environment of centrifugal gravity (=on the ring sections of the ship)?
2) What safety technology would the ship have against cases like this (maybe starting with whatever the ISS has for preventing fires on board)?
3) What levels of casualties would you expect, assuming a bunch of people are sent in to extinguish the fire as quickly as possible?

Hollywood do it like this.




First part was Newton's third law! I liked the film, it stressed me out though.
How would you articulate that?
That one scene? Tricky.
Absolutely no idea if it would actually happen like that but they threw some money at the film.