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Post by CELS on Apr 5, 2005 10:50:21 GMT -5
How do they work? The fluff says that drop pods are fired (not dropped) towards a planet with fantastic speed, to avoid them being shot down. Well, if these things are hurtling towards the surface at super-sonic speed, and hit the ground like a meteor, what's stopping the people inside from being reduced to jam? In fact, what's keeping the drop pod intact?
Those who have read Space Marine novels and played Dawn of War know that drop pods hit the ground with a deafening crack, often leaving huge craters. Obviously, there must be some sort of grav field at work here, to keep the people inside alive.
So how do they work?
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Post by Philip on Apr 5, 2005 11:01:08 GMT -5
I know you asked, but I can’t really answer this without bringing all my theories to the table.
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Post by Tynesh on Apr 5, 2005 12:48:20 GMT -5
The current FW model is quite confusing on this matter. It has an engine (rocket?) on the top - for propelling it ground ward and one underneath - to slow the descent.
I guess there must be a forcefield heat shield to prevent it burning up. I think some pictures show this in a way, with lots of plasma/gases being pushed around the craft by some field.
There has to be some thing that slows descent before impact because no matter how strong the pod is, it couldn't survive a high speed impact and then safely deploy the marines. The idea of making a crater is stupid in some ways - it would hamper the marines once they exit the pod if they have to climb out of a crater after landing!
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Post by Philip on Apr 5, 2005 14:09:41 GMT -5
The idea of making a crater is stupid in some ways - it would hamper the marines once they exit the pod if they have to climb out of a crater after landing! Or you could look at it as ‘instant cover’ and I don’t think the marines would have that much trouble with a hill. However I’m sure that some drop pods land a little lighter – support drop pods armed with weapon systems would have a problem with line of sight if the creator was too deep.
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Post by Tim_C on Apr 5, 2005 14:57:10 GMT -5
Well, based on what I read in Imperial Armour Vol. 2, the drop pod is fired earthwards by its top rocket engine, with the speed and direction controlled by the pod's Machine Spirit, upon orders from the orbiting drop craft (Battle Barge or similar).
At a height above the ground the bottom rocket engines (the pics in IA Vol 2 have a line of 3 exhaust cones) kick in, rapidly braking the pod and allowing it to land.
Personally, if you want to include DoW in the discussion, then I'd take the pods being dropped from the opening intro sequence, where the pods seem to brake heavily, not creating impact craters and such things.
Tim
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Post by Kage2020 on Apr 5, 2005 16:56:33 GMT -5
How do they work? The fluff says that drop pods are fired (not dropped) towards a planet with fantastic speed, to avoid them being shot down. The simple answer relates to assuming that the authors were after an image, rather than any sense of plausibility or verisimilitude. The answer is simply to borrow from other 'systems' that involve drop pods... reduce chances of being 'shot down' by having an increased number of ECM pods (i.e. chaff/EM dispensors/jammers, etc.), and so forth. They might come down at a fair clip, but they're also going to have to reduce their speed rather dramatically, i.e. 'counter thrust' that might be moderated by 'suspensor' systems. Saves bringing in other arguments that are, strictly, not necessary. ...often leaving huge craters. Obviously, there must be some sort of grav field at work here, to keep the people inside alive. It all depends on whether you believe that the 'artwork' defines the 'truth'. Personally I'd work on the principle that this is complete 'bunk'. Otherwise you're going to have to utilise 'inertial dampener fields' or their equivalent. For something like a drop pod that seems a tad over the top. Kage
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Post by Briareos on Apr 6, 2005 7:52:35 GMT -5
Given the size and functions of some of the Imperium's warmachines and transports, it seems more than likely that the AdMech routinely includes inertia controllers in several of its constructs.
For example, while suspensors (anti-grav devices) may account for Titans not sinking into the ground or collapsing under their own weight, the speed at which Warhounds or even knights Titans are supposed to move at would imply some form of control over their cinetic energy.
So drop pods are shot at their target and decelerate rapidly when they reach an altitude of a few hundred meters (maybe less). Personnally, I would tend to think that drop pods include an as-yet-undocumented blast-shield which is jettisoned when the deceleration reactors kick in. This shield's use is then two fold : it handles part of the heat and friction generated by very quick atmospheric entry, and it can also handle light and medium flak counter-measures. This way, we have a fonctional and somewhat protected drop-pod with only cheap shielding to replace after each use. Sure the physical shields could be replaced by energy shields, but that would divert energy better used by the engines and deprive the pod of a few tons of additional mass which might come in handy during its acceleration towards planet-side.
The creation of the crater could be something programmed in before launch, depending on the content of the pod and the nature of the ground. The crater need not be created by the impact, but could be dug by the energy soaked by the inertial-dampers.
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Post by CELS on Apr 6, 2005 7:59:06 GMT -5
Then everyone seems to agree that drop pods don't actually hit the ground like meteors. They are fired towards the surface with extreme velocity, but slow down when they get close to the surface. When exactly would they need to slow down? I think it would be interesting if someone when to the trouble of designing a drop pod, and came up with some numbers concerning their deployment speed and so on.
The Frost Bringers will probably be using a helluvalot of drop pods, considering their combat doctrine.
Grav-plates seem like a good investement for what is obviously a valuable and re-usable vehicle. It does, after all, carry valuable cargo, and even a Machine Spirit!
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Post by Briareos on Apr 6, 2005 8:25:36 GMT -5
Of course, having the pod decelerate from their "mach 2+" to about 100 km/h doesn't mean they'll impact the ground with the gentleness of a feather The limit on the impact speed depends on two factors : the pod has to be able to soak up the stress of the landing, and the content of the pod must also be in one piece after the impact. We can imagine that a dreadnought-pod would be significantly faster than a marine pod - firstly because its cargo is more precious and thus needs to be reach the ground faster in order to avoid counter-measures. Secondly, the dreadnought itself is more sturdy than the average marine and can soak up more kinetic stress. Following-up on the disposable shield idea ; said physical shield could also be used to give the pod a more aerodynamic profil... Because given the current shape of the drop-pods, they are as air-profiled as bricks. It looks "cool" and gives it a wide base to stand on when on the table-top, but isn't really functional.
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Post by Philip on Apr 6, 2005 9:45:24 GMT -5
Well seems people aren’t that adverse to high tech in 40K.
Two thoughts string to mind: First; if they use inertia dampeners then the can decelerate as quickly as they like. Second; the power fields in RT power weapons destabilise matter so that it can be crushed/ cut with ease.
So the drop-pod could hit ‘like a meteor’ as the impact would have no effect on those inside due to inertia dampeners, and the ground could be ‘destabilised’ by the power field to turn even plas-crete into something akin to an airbag (plas-crete could act like pyroclastic flow, setting up hard when it stops moving and the power field burns out).
As for aerodynamic, again why not the same power field shield used in landing, if it could more plas-crete it can move air.
As to design and how it works: that where my theories start to kick in, what is outlined above it already in 40K in various bit and bobs and it matches the image: the clues are their people.
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Post by Tim_C on Apr 6, 2005 12:47:16 GMT -5
Well, here's a selection of points from what it says in Imperial Armour Vol 2: Quote 1: Quote 2: The powerplant is a single FV-50-75 Retro-rocket (for the troop version). Empty, the pod masses 14 tonnes, and descent velocity reaches 12,000kph. A slow descent compared to Apollo craft, whose crew capsules reached 40,000kph when they landed back on earth. Here is where I got the figures. So, I don't think fancy inertial dampers are required, especially when you've got the bio-engineered Marines racked inside, all cosy in their power armour. Just a solidly built capsule around (essentially) a dual-exhaust rocket engine. Tim
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Post by Tynesh on Apr 6, 2005 17:39:18 GMT -5
A overly hi-tech answer applied to a fairly basic piece of military hardware, nice try though, it needs to be kept simple.
I think it would be needed on the troop ones. Despite their uber-human abilities, Space Marines in full power armour are not much more than flesh in a big heavy box. It is unlikely that they would survive such rapid decceleration from 12,000 kph to 0 kph without that flesh hitting the bottom of the power suit and causing some damage.
I think there is mention of inertial dampeners in the 1st Eisenhorn novel when they drop pod down to the alien planet.
Dreadnought pods might not need the built in dampeners as I'm sure the actual pilot is in some form of dampening field already.
But yes, I think that the marines would need some form of dampening to prevent damage. Just remember that the astronauts were landing on a forgiving surface - water - and even cosmonauts who landed on Terra firma were slowed to only a few 100kph by parachutes before impact. This is not a luxuary the drop pods could afford.
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Post by Kage2020 on Apr 6, 2005 18:14:07 GMT -5
Again, let's keep "power field theory" out of this discussion.
'Nuff said.
Kage
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Post by Philip on Apr 6, 2005 18:26:37 GMT -5
A overly hi-tech answer applied to a fairly basic piece of military hardware, nice try though, it needs to be kept simple. And inertia dampeners aren’t overly hi-tech? I quite sure from a Physics point of view – disrupting bonds between atoms is way easier than inertia dampening.
Again, let's keep "power field theory" out of this discussion. Didn’t put it in, not going to put it in. The power field I mention was just the one already in the universe. I thought a ‘air bag’ sounded fun, but hey, I was matching it to the image. So we can have inertia dampeners, but not a force field – bizarre.
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Post by Kage2020 on Apr 6, 2005 22:34:09 GMT -5
And inertia dampeners aren’t overly hi-tech? No, they are horrendously high-tech. I wasn't advocating using them, rather questioning the image and indicating the directions that one might take if you buy solely into the image rather than questioning that image. (I realise that you're not addressing this to me, but I did mention them as well!) As stated elsewhere, you see the Image and go "Hey, let me create a reason why that is correct!" I, on the other hand, look at it and go "So, the Image is incorrect, how might it actually work?" But whatever. It comes from not doing anything original! Forcefields as described in the 'fluff' - not your 'magic field creators', Philip - wouldn't quite work as an airbag, IIRC. Kage
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