[MERCENARY] Combat at -180 degrees C

Mithras

Mithras

Banded Mongoose
Hi,

I want to run a Mercenary ticket on a world like Titan, methane liquid seas, dense unbreathable nitrogen atmosphere and temperatures at a crippling -180 degrees C.

Combat Environment suits, battledress and vacc suits willprotect the characters - but, my god - what about the bloody equipment! I read about engine oil freezing in WW2 Russia. What about firing an ACR or a Fusion GUn under those conditions. I've read that batteries are horribly inefficent at temperatures like -20 and -30. What about -180!!!!

Is war in this environment impossible? Will the inhabitantshave resolved the problems and have it easy over the invaders???? Can tech survive?
 
Yes, I have enjoyed the occasional spells of -20 .. -30 C during the winters and it really wreacks havoc on car batteries unless you have engine block heater and it is attached to electricity pole. The thing is that sometimes my (previous) car almost didn't start when I was leaving my office at the end of the day. Another interesting problem is that the coolant can freeze too and your car might end up heating up too much :P

Anyway, the oil freezing is a familiar problem in modern weapons but then again if there have been a huge number of battles in freezing conditions then better gun oils etc. would have been invented.

As there are trooper fighting in a fricking space I would think that the problems posed by extreme temperatures would have been solved.

An interesting thought, though.
 
lazer power pack might get screwed with. fusion reactors and guass guns should be unaffected. i'm not sure gunpowder would work...
in my games I homebrewed a HEV upgrade for weapons that costs 25% of the weapon.
 
SnowDog said:
Anyway, the oil freezing is a familiar problem in modern weapons but then again if there have been a huge number of battles in freezing conditions then better gun oils etc. would have been invented.
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Yes and no.

According to what I have read (re WW2 and modern arctic ops) to make weapons arctic ready you actually remove all the lubricant oils :shock:

And, AFAIUI, don't actually replace them with anything ... you just use the weapon unlubricated.

Phil
 
I'd imagine you'd have a problem with heat radiating through the armour from the inside - everywhere you walked you'd be melting the ice on the surface (rapidly). I think explosions would really superheat the air too.

As for lubrication... yeah I'd think it'd be better to not use weapons with moving parts. though you'd have issues with the weapon firing (heating up the barrel), which would melt ice crystals in the air, which would then refreeze in and around it.
 
In The Forever War by Halderman (IIRC) the greatest problem encountered when battling on a frozen nitrogen, helium, hydrogen type of moon (like Titan) is the fact that just the energy from the pressure of the suit and occupant walking across the surface is enough to make the frozen gases liquid unless one moves slowly. Going too fast greatly increases your chances of slipping across the surface unable to control your movements and direction of travel. And once you're on the ground it is very, very difficult to get back up since trying to do so creates even more liquid. One ends up freezing into the surface or causing a gas explosion because the heat exhaust fan comes in contact with the frozen suface. It is an interesting book.
 
Yah, the point to remember is that on worlds like this, you're not walking around on rock - you're walking on ice. And while the bulk of the solid stuff you're walking on is water ice (so cold that it may as well be rock in terms of hardness), there are pockets of ammonia ice, methane ice, hydrocarbon sludge, and maybe even some carbon dioxide ice if the pressure and temperatures are right.

Meanwhile, you're radiating heat like no tomorrow (it's got to get out somewhere) so if you're not heating the ground you're heating the atmosphere that you're venting into, and walking around on pockets of potentially very volatile stuff.
 
I actually have a funny story of what it might be like for the crew of an AFV in those conditions, though not quite that cold. I was a Mechanized Infantryman in the Army. While conducting some field operations in the winter, we slept inside our Bradley. During the night, water had condensated from everyones breathing and became a thin layer of frost and ice on the inside hull of the vehicle. Before everyone got out of their sleeping bags we had the driver turn on the heaters so we wouldn't have to get out of our bags in the cold. Shortly after, it was "raining" inside the vehicle from all the water on the inside hull melting. We were warm, but wet. Could use something like that as something to simulate conditions that affect morale.

Regarding using weapons without lube in those conditions, I could imagine that something like an AK would be fine, but a M-16 is machined to such close tolerances that I think it would jam, misfeed, dual feed, etc. alot. I've had em do that in optimal conditions.
 
tdwyer11b said:
Regarding using weapons without lube in those conditions, I could imagine that something like an AK would be fine, but a M-16 is machined to such close tolerances that I think it would jam, misfeed, dual feed, etc. alot. I've had em do that in optimal conditions.
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Graphite, perhaps?

Phil
 
Even current space tech includes ways of either lubricating or avoiding the need for same... Tech will become progressively capable of operating in hostile environments by default. You might need to make some adjustments to your Gauss weapons, but there would be ways of operating them, I'm sure. I'm pretty sure chemical propellants will fire pretty much the same at the low temperatures. You might need to get hold of ammo with a low-temperature primer though.

The effect of you and your actions on the environment is a fun thing to emphasise, though.
 
aspqrz said:
SnowDog said:
Anyway, the oil freezing is a familiar problem in modern weapons but then again if there have been a huge number of battles in freezing conditions then better gun oils etc. would have been invented.
Click to expand...

Yes and no.

According to what I have read (re WW2 and modern arctic ops) to make weapons arctic ready you actually remove all the lubricant oils :shock:

And, AFAIUI, don't actually replace them with anything ... you just use the weapon unlubricated.

Phil
Click to expand...

You are correct. Lubricants are removed from guns before going to field at such low temperatures.
 
At these temperatures, I find it hard to imagine that axles won't lock, brakes lock, any moving parts rendered useless. I also remember reading that (modern) batteries have substantially low power ratings in cold weather, but I suppose new superconducting cells might not suffer that problem. At low temperatures metal and plastics become brittle, I hope we can create plastics that do not become as brittle as glass in such temperatures! The more I think of the problems, the more terrifying it seems. I guess it can be rendered safe through the use of high-TL materials, such as nano-manufactured materials.

Weaponry - I would not want to be the first soldier to trying firing a laser rifle or fusion gun in that environment. What would happen inside the barrel as superheated gas meets super-chilled air in a confined space?

I can imagine an assaulting foce having really high tech gear that doesn't work, fighting a local enemy adapted to fight in -180 degrees C temperatures. How about electronically triggered accelerator rifles, no temperature stresses within the weapon, no moving parts.

But I would like to set up this campaign around an army adapted to fighting in space and on airless Moons that sufferes badly against an adapted enemy.
 
I remember reading a biography from the Eastern Front, a transport unit found their engine blocks frozen solid in the morning, and lit fires underneath each engine to try and thaw them out...!!! :0
 
You would assume that hi-tech gear would have advanced along with the ability to colonise such environments. Absolute zero temperature such as you'd get outside a spacecraft is -274 degrees celsius, so any equipment that would work there would work in terms of temperature, but maybe not in terms of the corrosive environment.

I like Mithras' idea: theme the ticket around hi-tech gear that doesn't work, a desperate struggle against better-adapted locals and the incredibly hostile environment and, afterwards, grudges against employers who didn't prepare/equip them properly.
 
I could be misremembering, but I think space is not at absolute zero, but it is very cold (or hot if you are close to the star). I think the pressure on Titan helps to contribute to the cold temperature.
 
The density of particles (one per metre cubed in an 'empty area of space) is so low that conventional temperature measurements aren't very intuitive. You do have direct impact from solar rays, and all the nasty prticles that come with them, so you could be badly irradiated if unshielded anywhere near a star. This would be due to interactions between said nasty particles and your body though, not the external atmospheric temperature as we'd understand it on a planet. You're right though - you'd almost never get ABSOLUTE zero temperatures.

Hmmm, that makes almost no sense now I've written it. I knew there was a reason I didn't do so well in my astrophysics degree all those years ago...

Either way - it's, like, freaking cold in space man!
 
I think I'll use that, if you don't mind!

tdwyer11b said:
I actually have a funny story of what it might be like for the crew of an AFV in those conditions
Click to expand...

Its easy to say 'in the future tech will have advanced so that these problems are overcome', and to some extent I agree, but I think Star Trek has pushed that too far, there is no problem that can be solved with a new type of phased plasma array or new type of energy. This is Traveller, and I always want my worlds to be dangerous. Somethings are just too hostile to overcome completely, and although the world needs to have been colonised, I still think that a safe place to live can still be a terrible place to fight.

I might have gotten the campaign idea from a distant reading of Forever War on that frozen moon, I must reread it!
 
For the lasers and other high temp guns, as far as the firing is concerned the temp differential between the 3500-5000 degree blast and an ambient temp of +100 and -180 is insignificant. The same for a power source like a RTG.

However, if the trigger switch material is the wrong stuff, it might just go snap.

Also, it's not too hard to insulate against cryo temps. Walking on Nitrogen snow may be a problem from pressure if you're near it's melting point, but not otherwise. Ice itself is a good insulator. I won't put my hand on a bare metal cryo line, but after chilldown it's got a nice coating of frost that is no worse than normal snow to the touch. Note this is water I'm touching, not cryo snow. But a decent EVA suit will insulate well enough to not be skating, again unless you're near the melting point anyway.

If you're using equipment that wasn't designed for the environment, it'll be the small things that'll eat you alive, as in some examples others have mentioned. My pet peeve is flowmeter coils opening up (breaking electrically) because of differentials in thermal expansion. Even in flowmeters made for cryo. They'll look good before chill-down, then you flow LOX, LH2, or LCH4 and they open up on you. You can replace them without breaking into the line, but you have to keep the ice out while you work.Good luck.

After that comes trying to get water ice out of cable connectors. Remove it and flush it with warm (>32 degrees F) acetone. Hope it doesn't eat the cable sheathing or anything.

Also, even things that aren't supposed to go from liquid to ice at the worst possible time. Like when we ran two hypergolic cryo propellants into a rocket's thrust chamber and got no fire. These should have burned on contact at anything above about 0 Kelvin. Turns out they iced coming out the injector and never met. Next question--how do you deal with a thrust chamber filled with ices of hypergolic liquids that are going to melt in an uncontrolled fashion soon?

Water in cryo lines: we call it "rocks." Not good.

One rocket company's launch was stopped because of ice buildup on a valve that physically blocked it from opening all the way. They'd tested in a low-humidity desert, then brought it to the sea coast for launch. They added a rubber boot to the valve, then tried again. Then they tried blowing nitrogen into the boot to displace the air. They couldn't keep the ice from interfering with their valve. They didn't make it into space because of a block of ice, and it pretty well ended the company.

Have fun. Be nasty. Give cryo burns. ;)
 
Mithras said:
I could be misremembering, but I think space is not at absolute zero, but it is very cold (or hot if you are close to the star). I think the pressure on Titan helps to contribute to the cold temperature.
Click to expand...

"space" isn't really at any temperature (other than the 3K background radiation from the big bang). What's in space, however, can be hot or cold. The planet Mercury be a vacuum world but its surface temperature is still hundreds of degrees C while the sun is up, and a couple of hundred degrees below zero when the sun is down.

While the sun is up, anything exposed to sunlight is absorbing its radiation and heating up. While it's down (or the object is in shadow) it's radiating its internal heat away and cooling down. IIRC the bay doors on the space shuttle are radiators that are usually opened up and kept in shadow while the shuttle is in orbit, so it loses heat quicker while the rest of it is in sunlight.

Titan's temperature is entirely due to its distance from the sun. Its thick atmosphere actually increases the surface temperature because it traps heat (i.e. a greenhouse effect) - it just doesn't increase it by much.
 
Mithras said:
At these temperatures, I find it hard to imagine that axles won't lock, brakes lock, any moving parts rendered useless.
Click to expand...

The metal moving parts on my Liquid Nitrogen cylinder valves work better when cold.....once the valves are closed and the regulator warms up to ambient temperature they become noticeably stickier.

Hmmm, used to know some of the low temp physics mob who play with Liquid He3 over in the Cavendish...I wonder if some are still there and respond to email.....*ambles*
 
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