Soliciting some suggestions from the list ubermensch/intelligentsia:
Information:
1) Running a scenario at ECC - low-G, no-atmosphere asteroid. FMAS.
1"/2m.
2) All combatants will be wearing powered combat armour (Battle Dress). Fast,
with enhanced strength and sensors.
Queries:
1) Effects of (both hand and rifle) grenades in low-G, Zero Atm. (both
frag and explosive). Do they work? Can you generate a concussion wave? Are
fragments likely to be dangerous further away? Are characters going
to be blown over/around (suppression) by any explosive force? Can people
throw further? How will this affect bounces? How will it affect accuracy?
2) Effects of low-G, no-atmosphere on:
Gauss Rifle/Gauss Pistol/Gauss SAW
Laser Rifle/Carbine
Tac Missile Launcher (GMS/P)
Plasma Gun (Man-portable)
3) Effects of environment on movement - faster, slower, easier, more
treacherous?
4) Effects of environment on wound resolution (if any) - automatic
sealing is present, but is there still an increased chance of an
over-large puncture causing death? How would you change things? Wounds
more severe? Or not?
Answers off the top of my head:
[quoted original message omitted]
Do regular, RL gunpowder weapons work in vacumn?
It's not too relevant to an SF discussion, but I wondered...
> At 15:45 2/18/02 -0500, you wrote:
All else being equal, grenades will go farther when launched.
No atmosphere means no or almost nothing for concussion grenades to work with.
I'd guess reduced effect.
Frag grenades are still going to generate fragments. There will be no air
resistance too slow them down, so in theory they will travel further.
> 2) Effects of low-G, no-atmosphere on:
Lower gravity will give you a flatter trajcetory, and no air resistance will
let equate to higher velocities, which will further flatten trajectory. This
will translate into longer range for projectile weapons.
> Laser Rifle/Carbine
No atmosphere means no attenuation of the laser beam. Longer effective range
here too.
> Tac Missile Launcher (GMS/P)
Right out unless they have steering jets instead of fins. If you have a
beastie, not sure if the extra mass for steering jets and prooellant would
offset the gain from lower G, especially as you also lose any atmospheric lift
effects.
If you don't have a VacTac missile launcher, you're better off bringing
buzzbombs.
> Plasma Gun (Man-portable)
No air resiatance + lower grav gives flatter trajectory as projectile
weapons above. No atmosphere means the plasma bolt will not lose energy to the
surrounding air as it travels towards the target. Longer effective range.
> 3) Effects of environment on movement - faster, slower, easier, more
Faster and more treacherous. You can get going faster, but you have the same
inertia when it comes to changing direction. Hopefully, the power armor can
help compensate for this.
> On Mon, Feb 18, 2002 at 01:51:59PM -0800, Brian Burger wrote:
Yes.
The gunpowder carries its own oxidiser with it - if it relied on
atmospheric oxygen, it wouldn't burn fast enough to propel bullets.
On the other hand, what will give you problems is lubrication - normal
grease will boil off quite readily. I don't know whether vacuum-safe
lubricants have been developed.
If you also let the weapons get cold (likely if they're in vacuo for a long
time), you have to worry about metal parts shattering too.
> On the other hand, what will give you problems is lubrication -
Plastics tend to lose their volatiles, which means they're no longer plastic.
There is at least one plastic which retains its properties pretty well in
vacuum. It's a Dupont product called Vespel, and if prices continued the way
they were when I was selling it, a single
Take a look at
http://www.nikon.co.jp/main/eng/society/rhnc/rhnc12ti-e.htm
somewhere (probably on this page, but i can't find it right now) they also
mention they had to switch to a special lubricant for vacuum use.
> Laserlight wrote:
Ray Forsythe wrote (and Brian Bell wrote something similar):
> >Tac Missile Launcher (GMS/P)
Whether the vector thrusters take up more mass (and cost more) than movable
fins depends very much on the intended range of the weapon. For
shorter-ranged weapons it's pretty much a toss-up today as to which of
fins and thrusters to use; thrusters may be slightly more expensive but allow
a considerably lower muzzle velocity than fins do for the same accuracy.
(Lower muzzle velocity = smaller launch signature = A Good Thing tactically
speaking).
Oh, and a rocket-powered missile launcher has very little kickback
whether
in an atmosphere or in vacuum. (A recoill-less gun would have problems
with
recoil, but I suspect that it'd be kick-forward rather than kick-back.)
> >Plasma Gun (Man-portable)
Much more importantly, the plasma bolt won't break up due to air resistance.
*MUCH* longer effective range in vacuum.
Regards,
[quoted original message omitted]
[quoted original message omitted]
Quoting Brian Burger <yh728@victoria.tc.ca>:
> Do regular, RL gunpowder weapons work in vacumn?
I doubt it.
Not for very long, even if they do. Think - very hot parts, very cold
parts next to each other. I suspect it'd jam very fast.
> It's not too relevant to an SF discussion, but I wondered...
From: "Laserlight" <laserlight@quixnet.net>
> Plastics tend to lose their volatiles, which means they're no longer
I once ran a SG scenario on a moon that had a thin atmosphere, and one of the
effects was that whenever a unit near a terrain feature (a hill or a gully)
took fire, the bullets & grenades kicked up a lot of moon dust, which was
represented by a cotton ball of "smoke".
Of course, there isn't any wind on the moon, so the cotton balls didn't move
or blow away, and during the course of the game the terrain on the battlefield
was slowly modified as the players took shots at each other.
-- Rick Rutherford
[quoted original message omitted]
Rick Rutherford schrieb:
> I once ran a SG scenario on a moon that had a thin
Actually, I'm not sure this was the right effect. Certainly there is no wind
to blow away the smoke and dust.
On the other hand, dust and smoke float in air and even rise if the air or
gases around them are hot enough. But without an athmosphere, dust particles
kicked up will continue on ballistic trajectories. Gas will expand and thin
out spherically. I suspect that dust and smoke on an asteroid will disperse
faster than in quiet air.
Greetings
[quoted original message omitted]
From: ~ On Behalf Of Tomb
Sent: 18 February 2002 20:46
Subject: [OT] oddball enrivonment questions
> 1) Running a scenario at ECC - low-G, no-atmosphere asteroid.
> 2) All combatants will be wearing powered combat armour
I'll assume you use the term to indicate the old Traveller armour, which for
list members unfamiliar with the game "consists of a
complete vacuum-suit-like array of metal, synthetic and electronic
armour". I always took this to mean the character ended up looking like an SW
Stormtrooper.
Are you sure you want to make the forces that tough? You could have far more
fun (low calibre rounds and melee weapons) with soft suits, but maybe that's
just my old Paranoia GameMaster tendancies rising to the bait.
> Queries:
> 1) Effects of (both hand and rifle) grenades in low-G, Zero Atm.
A fragmentation grenade will work as well as it ever did against Battle Dress,
which to my mind should mean unlikely to be effective. What do you mean by
explosive, if not fragmentation?
> Can you generate a concussion wave? [No]
Yes, the fragments don't slow down until their ballistic path leads them back
to luna firma. However, the likelihood of being hit is no higher than normal.
The fragments fly out in a sphere (or whatever the dispersion pattern is for
your grenade), half hit the ground and most of the rest go into space. These
are way over escape velocity so they won't be seen again. The remainder fly
near enough to level to be dangerous for some time, but they are dispersing in
all directions so your chances of being hit are slight, outside the usual
danger space.
> Are characters going to be blown over/around by any explosive
Now for a brief word on terrain. You've got rocks, gravel and
sand. The sand could be ultra-fine dessicated stuff that for
many purposes acts like water, but you can't see through it and if you fall
into a deep pool in low gravity you are likely to become completely
disorientated. If the pool is not too deep, you eventually sink to the bottom
and (oxygen permitting) can drag yourself out on your hands and knees if you
don't just stand up to discover you were "trapped" in only two feet of sand.
I'll add a note on some other variations at the end.
> How will it affect accuracy?
Your troops will be able to see further and throw further, but they won't be
much more accurate unless they use grenade launchers with dinky little
integrated laser rangefinders.
In reality you will use grenades as you always have. There might be some enemy
in the crater up ahead, so you throw in a brace of grenades and go over the
lip as soon as they have gone off. There's scope for a terrible accident here,
as all weapons are soundless and you won't see any flash unless it is
reflected off a nearby object!
Any sort of flash grenade won't be much use since the suits
(even ordinary emergency ones) will have photo-reactive
visors quick enough to save the sight of anyone glancing into the sun or a
nearby ship exhaust.
Illumination grenades, on the other hand, may be useful on the day side as the
lunar landscape tends to alternate
between brightly-lit areas and deep shadow. Your powered
armour is likly to have some sort of thermal imaging intended to sweep these
shadows for lurking snipers. Any sort of light amplification will be foxed by
the contrast unless it is electronically filtered.
Assuming it combusts in vacuum, any sort of smoke will simply
disperse at once. On a related note, anti-laser aerosols won't
work either. I can't make my mind up about chaff, but I suspect it will simply
fall too quickly to be useful.
> 2) Effects of low-G, no-atmosphere on:
Gauss weapons will work beautifully unless they have a problem adapting to the
cold or the heat, or have some loading mechanism dependant on an atmosphere or
a certain amount of gravity. The main limitation will be the sights and the
fact that low gravity and no atmosphere normally mean a small moon or
asteroid, so the horizon is very close. Again, the weapon effect is improved
but the accuracy remains the same.
> Laser Rifle/Carbine
Depends on your PSB. Lasers you can see* will do far better in a vacuum, as
will any that are affected by water vapour. "Invisble" lasers, which should be
superior anyway, will work
as normal. Rapid-fire laser systems may have cooling problems
unless they are designed for zero-pressure.
* Except that in a vacuum you'll only see them when they hit, or pass through
a very temporary cloud of debris from a casualty.
> Tac Missile Launcher (GMS/P)
May need some modification for these conditions. In a vacuum,
a fin-guided missile needs to revert to TVC (thrust vector
control?) where you put the fins inside the rocket exhaust. No nasty recoil,
but the rocket exhaust playing over the spent propellant could give a very
high signature, especially if it also kicks up a surface layer of dust.
> Plasma Gun (Man-portable)
Again, modify it for zero-pressure and it should still work,
unless there is an unsurmountable cooling problem. The range will still be
limited by the muzzle velocity of the weapon, since as I understand it plasma
weapon technology will basically consist of a race to get the pulse to the
target before it disperses.
Artillery will still work if you slow the rounds down to below escape
velocity. The ballistics will be pretty strange, and you end up with something
more like a mortar, but you should be able to hit most points on the moon.
> 3) Effects of environment on movement - faster, slower,
I've already described the basic surface. You may also get scree slopes and
cliff faces where every boulder is loose; a single falling rock can start a
rock slide that has been building up for a million years or more.
Throw in a cravasse or two, but don't put spikes at the bottom or your
participants will think that you are being flippant.
If there is a trace atmosphere then all bets over the lack of water are off;
gasses stand in for liquids and can sublime from frost to vapour without
warning. Clouds and mist are possible, though they evaporate quickly. When
they condense back down again they can freeze and fall as a very light layer
of snow.
Given a very cold planet, conditions become extreme. Elements normally found
in gaseous form lie instead in pools, and can even form sheets of ice.
Crystals of frozen gas can get underfoot or coat rock surfaces. Compared with
the surroundings, even a well-insulated suit is blazingly
hot and will cause the gas to evaporate on contact. It can even cause rock to
shatter with explosive force.
> 4) Effects of environment on wound resolution (if any) -
Are we talking trauma maintenance here? [a la Forever War?]
> but is there still an increased chance of an over-
On several counts. Anything travelling with enough force to blow a hole in
Battle Dress is not going to do much good to whatever is inside it. You may
also get injuries from spalling, or a projectile may ricochet inside the
armour rather than exit. Decompression will lead to very rapid exsanguination
even if it is quickly patched, unless the suit can restore full pressure.
Damage to the life support unit on the suit will be fatal unless shelter is
nearby. Finally, if a corpsman does get to you, what can he do if you're
behind all that armour?
For these reasons, trauma maintenance only saves you if you've lost all or
part of a limb. Injuries to the head and torso are still fatal.
> Wounds more severe? [Oh yes]
Books I swiped these thoughts from: