A bit of analysis: Posleen War

[Ahriman238]

True. Of course, in a galaxy full of Klingons, the Darhel would probably never have been remade in that image in the first place.

It's implied that nonviolence is something of a galactic 'norm,' with a substantial majority of advanced races in humanity's neck of the galaxy being either naturally or artificially much less violent than humanity, even if they're physically capable of it (like the Himmit, who would probably have no problem with pushing a button to blow something up from the other side of a mountain range if it was important).

In a galaxy dominated by advanced nonviolent races the Klingons would probably not have been able to develop FTL travel on their own- they'd be the Darhel, or their counterparts, with the same problems of fighting among themselves.

Which is actually a good question to ask about Proud Warrior Races in general- in real life, most cultures that have a strong focus on personal honor and vindication through combat aren't at the forefront of technological and economic growth. The ones that thrive are usually either good at directing violence outward and avoiding it internally, or just not especially bloody-minded.

That's more or less what I said. In the first book the Galactics claim to be nonviolent because violent species invariably wipe themselves out before discovering FTL. I was musing on whether or not that was a lie.

IIRC, and without turning this into a Trek thread, the Klingons were a medieval-ish level civilization that were conquered by aliens, the Hurq. The enslaved Klingons managed to learn enough about Hurq technology to overthrow them and become an interstellar empire. This is why the Hurq had the Sword of Khaless, and supposedly turning the TOS era the Klingons were still flying basically Hurq ships, but in the TNG period they've designed and built more ships of their own.

It also explains all the primitive anachronisms in a spacefaring civilization.

[Ahriman238]

Another day, naother update. I decided to break up the Posleen part since it's taking so long. The first part I have is just the notes on their biology. I seriously did not realize how much information that was til I wrote it all down in one place. Enjoy.

Posleen:

The Posleen, which is actually a shorthand bastardized version of their name of themselves Po’slen’ar(or 'People of the Ships,') were genetically engineered as a warrior race, the “ultimate survivors” able to live and thrive on every hellish planet known. In appearance, they are centaur-forms with a generally reptilian look and light yellow in color. They have long serpentine necks, and yellow eyes. They have clawed hands with 3 fingers and an opposable thumb, and tails. Their hind legs have an extra joint. They wear harnesses for carrying food and ammo, and sometimes large pouches. Normals about average horse-sized, God-kings are bigger, around the size of a large horse, and have a very mobile red crest on their heads. Posleen blood is bright yellow. Posleen are hermaprhodites.

The vast majority of the Posleen have roughly the mental abilities of a chimp, we call them normals, Posleen call them oolt’os, oolt in groups. A small minority between 10 and 20% have the mental capabilities of an eight year old, these are called cosslain by the Posleen and superior normals, or just superiors by us. About 1 in 400 is a Kessentai, or God-king, fully sentient, as intelligent or more so than humans, and with the ability to ‘bond’ with lesser Posleen. God-kings are, as previously noted, much larger and stronger than normals, and have a distinctive crest.

This bond is one of the more frustrating aspects of the Posleen, it’s never described in much detail or quantified in a meaningful way. We don’t know what the bond ultimately does for the Posleen. We do know that a normal can only be bonded to 1 God-king. We know that touch is needed to initiate the bond. We’ve seen a single paragraph from the perspective of a Posleen normal, it focused on the bond and its instructions, eager to please its master even ahead of its own survival. We know that when a God-king dies, his peers have only a few minutes to re-bond his oolt or it will be impossible to bond them for 2 weeks. We know that when a God-king dies his normals either go berserk or flee, and that they ditch the more complicated heavy weapons when they do so. Eventually all unbounded Posleen, whether born free or released through the death of their God-king, seek out a God-king and the bonding. More than that, we don’t know. Is it chemical? Psychic? I don’t know. Maybe they talk about it more in one of the spin-off books?

The Posleen are extraordinarily resistant to radiation, while rads are still dangerous in high enough concentration, lethal does for humans will only kill off a few of the weakest Posleen and make the others varying degrees of sick. As a shorthand for what’s actually a pretty complicated relationship between individual resistance, risk factors and survival rates, I’ll just say it takes, on average, 3x the rads to kill a Posleen as a human. Thanks to their genetically engineered biology, Posleen can eat any form of plant or animal life known, and need never fear disease, natural or otherwise. Similarly, and probably thanks to their ability to survive in a wide variety of environments, no chemical weapon has been found that will kill Posleen, though research was abandoned fairly early on. At a minimum, they are completely immune to cyanide, mustard gas, and VX.

Contrary to the image of the seething alien horde come to eat everything, though they are that, the Posleen can go for considerably longer without eating or drinking than humans. They are also more resistant to temperature extremes. In flat, open terrain the Posleen can reach 20 kph in a gallop and maintain the pace for several hours before resting. However, since their bodies are shaped like a centaur’s they are not at all suited for climbing as we understand it. The Posleen ankle, like a horse’s can be easily broken when running at speed, so they must beware of treacherous footing. Posleen can move only slowly through forested, rocky, or icy terrain and have only rarely climb over the heaps of rubble created in urban combat. The Posleen find it very difficult to ford rivers, nearly impossible while under serious fire. This, along with their lack of logistics where they can’t scrounge and hunt for food, puts a serious cap on the locations Posleen can go and fight. Caltrops are also a very effective area denial technique, but if the Posleen believe there’s a worthwhile prize at the end they can and will overcome them with human waves.

Posleen eyes are strongly implied to see a fair ways into the ultraviolet, while being weak on the red. When Mike looks at camo-painted tanks under a Posleen-view filter set for the light of Diess’ sun (man, suits can do anything) they appear fluorescent. Posleen have exceptional night-vision, though not really as good as a man with night-vision goggles. They also adapt a lot quicker and easier to sudden changes in light level.

Posleen reproduction is simply insane. Not Ocampa-level insane, but up there. As previously mentioned, Posleen are hermaphrodites, and each has an ovipositor. For everyone who didn’t do well in bio, that means each member of the Posleen is both sexes, able to carry their own young, or fertilize others. An ovipositor is an organ for the precise placement of eggs, like some wasps inject eggs through their sting, thus their stinger is an ovipositor. How is this insane? Well, we’ve seen a Posleen lay an egg, they basically vomit it. So why the ovipositor? I have a theory. In a later and much more… together series by Ringo, March Upcountry, he had aliens, the Mardukans reproduce in an exotic way. The ‘male’ produces unfertilized ova and inserts them via ovipositor into the ‘female’ whose womb-equivalent is filled with sperm-equivalent to fertilize eggs, which the ‘female’ then carries to term. I believe he started the idea here and only completed it there.

Posleen grow to full maturity in only 2 years. Most of this time will be spent in a pit or pen, where the nestlings fight over the limited supplies of food tossed in, and kill and eat each other to survive. Every so often, randomly chosen nestlings will be scooped out and consumed by the adult Posleen. Posleen eggs laid on the march are tucked away in dark corners and abandoned, the young Posleen either lives to adulthood and seeks out others of its kind on its own, or it dies unnoticed and unremarked. But here’s the thing: even with their brutal childhood and high mortality rate as youths, the Posleen population growth just keeps going. On every world they settle, it’s overpopulation pressures that drive them to conquer new worlds and eventually lead to the devastation by nuclear fire (more on that later.) Consider that the Posleen invasion force by the end of the war is six times greater than the number that landed. This despite a massive global campaign in which the host absorbed countless billions of bullets, tens of millions of artillery barrages, and thousands of nukes, and still managed to destroy every army fielded against them. They literally reproduce faster than the combined armies of the world can kill them. This more than anything is what makes them ‘ultimate survivors,’ nature’s time-honored and efficacious shotgun technique.

All Posleen possess a genetic memory, though it’s more for handing down useful skills than detailed and specific information. All Posleen, even wild-born who have never met another of their kind, know the rudiments of the Posleen language. God-kings all understand the basics of starship operations, though generally only the basics. Specific bloodlines seem to contain some specialized knowledge, for example a particularly technically skilled God-king’s spawn may inherit his skills, or they may not. For this reason, the God-kings trade superiors and normals as breeding stock. Even normals can have a knack for things like masonry or farming, if enough of their predecessors did these things, and can do them with some minimal supervision by superiors. Presumably this is how Posleen agriculture and manufacturing works. All Posleen instinctively know how to hunt, fish, forage, find or build secure shelter, navigate wilderness, the basic outdoorsman’s skill set.

[Simon_Jester]

Posleen eyes are strongly implied to see a fair ways into the ultraviolet, while being weak on the red. When Mike looks at camo-painted tanks under a Posleen-view filter set for the light of Diess’ sun (man, suits can do anything) they appear fluorescent.

For something with the suits' processing power, and a general AI, this is actually not hard to do.

In a later and much more… together series by Ringo, March Upcountry, he had aliens, the Mardukans reproduce in an exotic way. The ‘male’ produces unfertilized ova and inserts them via ovipositor into the ‘female’ whose womb-equivalent is filled with sperm-equivalent to fertilize eggs, which the ‘female’ then carries to term.

Hey, it works for seahorses...

[Ahriman238]

Hey, it works for seahorses...

Actually, I never thought about seahorses. Is that more or less how it works for them? I know the male carries the young, but nothing truly specific.

The unit of Posleen bonded to a particular God-king is called an oolt. It is generally around 400 Posleen, but can be as small as 200 or as large as 600. For the sake of brevity, I’ll use the military shorthand from the book and just call them companies. Just so you understand that a ‘company’ covers a flexible range of sizes. They also tend to form larger units, consisting of 16-20 God-kings and their companies called an oolt’ondar, or brigade, led by a senior God-king called a Battlemaster. I’ll explain why when I get to ships.

For melee combat almost every Posleen is equipped with a mono-edge palmate knife. In the first book, superiors and God-kings had ‘boma blades’ sort of short glaives, also mono-edge. In later books, large numbers of normals had boma blades as well. Feral Posleen use fire-hardened spears, and in extremis they always have sharp claws and teeth to fall back on.

For normal weapons the vast majority of Posleen are armed with 1mm light railguns. The railguns aren’t quite the monsters the US Navy played around with a while back, for one they can be stopped by a jersey barrier, for another when hitting a person they generally cause death within moments due to trauma and blood loss but don’t actually blast people into meaty chunks.

The unusually poor, or just starting out companies will instead have a shotgun similar in principle to a 40K autogun. It’s basically a shotgun, it works the same way as a shotgun, just with some more advanced chemistry, ballistics and material science behind it. The shotguns shoot the same ammunition as the light railgun, and in at least one case a God-king uses a shotgun launched a super EMP grenade that fried even the hardened stuff for a couple of miles, except for Posleen and GalTech. All Posleen weapons are sightless, but Posleen tend to be very good shots within 50 meters or so.

The Posleen arsenal also includes 3mm heavy railguns that can at least soft-kill an Abrams, gigawatt and terawatt lasers, heavy plasma rifles and hypervelocity missile launchers (HVM.) Mostly, these are kept by the God-kings and issued out to the superiors as special heavy weapons, however it is not unheard of for very wealthy veteran companies to be armed mostly with heavy weapons, or for them to be issued for special missions.

The lasers, plasma weapons, and heavy railguns are sort of just there without extensive discussions of how they work (though they describe an ACS terawatt laser in Faire) while the HVM is basically the grav-gun’s bigger, meaner cousin. A ‘football-sized’ missile that accelerates to ‘a large percentage of light speed,’ within 20 meters of leaving the barrel using an onboard grav-drive. HVMs pretty much flatten everything, no combination of armor and shields is found to stop them, few bunkers are that tough. The only things that aren’t immediately killed by HVMs are SheVas and WWII battleships, and even these are heavily damaged, and must regard HVMs as serious threats. Though, some Posleen are dumb enough to fire HVMs at targets 3 meters away.

Please note there at least 3 models of HVM. What I think of as the ‘standard’ model, the one issued to superiors, has a six-shot revolver style magazine. Several God-kings have ‘multiple repeating’ HVMs, and their ships use a scaled up HVM kinetic Impactor as anti-ship weapons and as the preferred option for orbital bombardment. These are explicitly stated to be equivalent to 10 kilotons.

Laser weapons, like in 40K are very good against armored targets, like tanks or the ACS, they can even be fired in a continuous mode to sweep areas.

Plasma guns are described once as being able to shoot through a battleship, and on another instance are said to destroy 200 sq ft of steel with one shot. Plasma weapons vary greatly in effect, possibly due to being different models? But while they deliver massive amounts of heat damage to most things, they are not so good at penetrating armor.

However, science marches on, even among the Posleen. I just started on Eye of the Storm and in the first freaking chapter we have a specialized anti-SheVa weapon and a ‘casta’ HVM. Dr. Casta, if you’ll recall was the man who came up with the hell-weapon. So, in-universe a casta weapon is anything that scatters a large number of megaton-range antimatter bomblets over a wide area, basically, antimatter cluster bomb. The Posleen casta fires a modified HVM that that traces an arc over the battlefield at hypersonic speeds and dumps 200 bomblets, 16 MT each, in a programmable pattern. Shit. If they’d had that during the invasion… Plus, I really feel appalled that such weapons have become relatively commonplace.

Anyways, most God-kings use a vehicle called a tenar. It’s an open topped anti-gravity sled, described sometimes as being like a grav-sled, and others as being sort of like a flying jeep. Each tenar has very advanced sensor and communications abilities, as well as access to the Posleen Datanet. The ‘Net has reports and interstellar communications, the program used to divvy of up conquests as well as the entire archived history and science of the Posleen. Too bad nobody thought to include an index or a search engine. Some God-kings learn to patiently tease information out of the ‘Net, but most never learn the skill. Tenar sensors can spot human bio-signs at a range of 400 meters, and can detect electronics from a few hundred meters. However, not all God-kings keep an eye on their sensor readouts, so they’re as likely not to notice or care about humans who don’t make trouble. When hit just right by a .50 cal or greater, a tenar explodes with the ‘force of a 500 lb bomb.’

The truly terrifying thing about tenar is that they can mount nay of the heavy weapons used by the Posleen, from the humble heavy railgun up through the laser and plasma weapons, to the mighty HVM. When a weapon is mounted, with the sensors and computer support of a tenar behind it, it can be fired with pinpoint accuracy. It will then swiftly track and almost instantly fire on any rockets, missiles, or aircraft that lift above the horizon. Plus any source of radio emissions, including and especially radar, and snipers. Actually, unless a large number of people open fire simultaneously on the Posleen, the first few people to start shooting are going to get annihilated.

The tenar can fly at an altitude of roughly 1 kilometer, at least, buzzing the megascrapers of Diess. They can reach speeds of at least 300 kph (186 mph.) The first time I read Hymn, years ago, I assumed the destruction one-by-one of the supersonic Banshee shuttles implied the tenar could themselves somehow fly at supersonic speeds and pursue, madness in an open-topped craft. Re-reading the book, I see this is not so, it was probably the result of several God-kings getting a shot as the craft entered and left LOS, and the tenar that came up to investigate the wreckage were not a pursuit force. Most God-kings learn early on to keep moving randomly to avoid sniper or AA fire.

There is also an enclosed, armored version called a tenaral. It’s called a flying tank in contrast with the tenar as a jeep. The tenaral is implied to be capable of greater speeds and altitudes by their swift progress through the mountains in Dance. The downside is that the tenaral gives up the swivel and autotargeting capabilities of the tenar, and there really isn’t any other sort of targeting system, not even an iron sight, so their accuracy sucks. To the point where there’s doubt about their ability to hit a SheVa in a strafing run. The tenaral’s armor is not proof against a hail of penetration rounds from M1 Abrams guns.

There is some question as how to common tenaral are. In the first book, the Posleen are said to have some armor in every C-Dec, with every brigade. In Dance, with the forces of an entire globe behind him, Tulo could only scare up 60 tenaral and pilots, and no one had a clue what they were, despite their being in the initial GalTech briefing.

Posleen weapons and something of tactics. Just need to cover their space combat and what bits of culture they have. As well as a brief word on outliers like the five percenters and Tulo, and I'm done with the Posleen.

I'm continually amazed by the glut of notes I now have on this series.

[Simon_Jester]

Hey, it works for seahorses...

Actually, I never thought about seahorses. Is that more or less how it works for them?

Not really; that was a quip.

For normal weapons the vast majority of Posleen are armed with 1mm light railguns. The railguns aren’t quite the monsters the US Navy played around with a while back, for one they can be stopped by a jersey barrier, for another when hitting a person they generally cause death within moments due to trauma and blood loss but don’t actually blast people into meaty chunks.

Hmmm. I wonder what the ballistics are like. Maybe the rounds tend to break up on impact, cratering against concrete rather than penetrating but causing vicious wounds? Or do we have 'through-and-through' injuries on humans shot by 1mm rounds?

The shotguns shoot the same ammunition as the light railgun, and in at least one case a God-king uses a shotgun launched a super EMP grenade that fried even the hardened stuff for a couple of miles, except for Posleen and GalTech. All Posleen weapons are sightless, but Posleen tend to be very good shots within 50 meters or so.

How a shotgun could fire a railgun round (which would have no propellant) is beyond me. Also, where's that EMP grenade from?

Please note there at least 3 models of HVM. What I think of as the ‘standard’ model, the one issued to superiors, has a six-shot revolver style magazine. Several God-kings have ‘multiple repeating’ HVMs, and their ships use a scaled up HVM kinetic Impactor as anti-ship weapons and as the preferred option for orbital bombardment. These are explicitly stated to be equivalent to 10 kilotons.

This is actually trivial for a relativistic weapon.

A good working rule is that at 0.01c (yes, that is one percent), an object's kinetic energy will be one kiloton per kilogram of mass. That can be scaled up or down- at 0.02c, four kilotons per kilogram; at 0.005c, 0.25 kilotons per kilogram.

Scaling on that rule of thumb will work fairly well until relativistic effects become important; as long as you don't mind being off by 10-20%, you can keep using it up to around half of light speed.

Check the math if you don't believe me.

Ringo grossly underestimated the amount of muzzle velocity it takes to make a "football-sized" missile into that deadly a penetrator round.

However, science marches on, even among the Posleen. I just started on Eye of the Storm and in the first freaking chapter we have a specialized anti-SheVa weapon and a ‘casta’ HVM. Dr. Casta, if you’ll recall was the man who came up with the hell-weapon. So, in-universe a casta weapon is anything that scatters a large number of megaton-range antimatter bomblets over a wide area, basically, antimatter cluster bomb. The Posleen casta fires a modified HVM that that traces an arc over the battlefield at hypersonic speeds and dumps 200 bomblets, 16 MT each, in a programmable pattern. Shit. If they’d had that during the invasion… Plus, I really feel appalled that such weapons have become relatively commonplace.

Posleen are getting desperate, I think- by this point they are fighting on the defensive against human counterattacks. And Posleen, like humans, are smart enough to learn once you start killing off the dumb/traditionalist ones.

That said, the physical size of antimatter munitions required for 16 MT bomblets is such that it wouldn't be practical from a shoulder-fired weapon...

There is some question as how to common tenaral are. In the first book, the Posleen are said to have some armor in every C-Dec, with every brigade. In Dance, with the forces of an entire globe behind him, Tulo could only scare up 60 tenaral and pilots, and no one had a clue what they were, despite their being in the initial GalTech briefing.

...Huh? Could you quote that briefing for me?

[Ahriman238]

Hmmm. I wonder what the ballistics are like. Maybe the rounds tend to break up on impact, cratering against concrete rather than penetrating but causing vicious wounds? Or do we have 'through-and-through' injuries on humans shot by 1mm rounds?

Unclear. Good thought though, I'd sort of assumed the rounds were either that tiny (being only 1mm) or Ringo just had next to no idea what a railgun was.

How a shotgun could fire a railgun round (which would have no propellant) is beyond me. Also, where's that EMP grenade from?

You've got me there, that's one reason I think Ringo only barely understands what a railgun is, if at all. As for the grenade, about a third of the way through Dance. A Special Forces team lead my Mueller and Mosovich are being pursued by several companies of Posleen. They get artillery support to cover their retreat, then one of the God-kings says that Tulo has prepared something special for those teams, pulls the shotgun, fires the grenade, which immediatly kills their radio and Land Warrior gear, but leaves Mueller's AID alone.

It doesn't seem to be a common thing, but it bears some mention, since I'm trying to clarify capabilities for vs. debates. Even if it's not exactly a game changer, I can see it the EMP grenades as being both a nasty suprise the first time they're used, and something that could get really annoying after a while.

There is some question as how to common tenaral are. In the first book, the Posleen are said to have some armor in every C-Dec, with every brigade. In Dance, with the forces of an entire globe behind him, Tulo could only scare up 60 tenaral and pilots, and no one had a clue what they were, despite their being in the initial GalTech briefing.

...Huh? Could you quote that briefing for me?

Why certainly.

“C-Dec, Command Dodecahedron. Core Unit of a B-Dec, or Battle Dodecahedron. Twelve-sided cube. Random mix of interstellar weaponry on eleven facets. Antipersonnel secondaries. Interstellar drive. About 1600 personnel nominal, buncha God-Kings, some light armor. Locks on twelve Lampreys to form a B-Dec, which is the central fighting unit of the Posleen.”

Emphasis mine, not from the actual briefing, but the helpful flash cards put out by Galtech to teach recognition of Posleen weapons and vehicles. Interestingly, there are 25 cards despite there being, to my knowledge, 8 weapons, 2 vehicles, and 4 ships. Anyways, I doubt there's any insight on the flash cards that wasn't imparted to the ocnference that made the flash cards.

He stewed as the scattered battalions and their vehicles, including the Posleen tanks used for ship security, were reloaded into the vast dodecahedron. Thousands of normals and their God Kings filed into the cavernous holds packed with cold sleep capsules and all the machinery necessary to set up a Posleen civilization.

Al, the God-king flying the C-Dec Mike blows in Hymn, reacts to his son's violent death by recalling his forces protecting the grounded ships, including his armor, and lifting off. Also established use of stasis pods in Posleen intersteallar travel. I had wondered how they kept the companies from slaughtering each other out of boredom.

[Raxmei]

My best guess at how you'd shoot 1mm railgun rounds out of a shotgun is to put a whole bunch of them into a shotshell with some conventional propellant (or possibly unconventional) basically to use as unnecessarily precisely made ratshot (1mm is really small for shotgun pellets). Of course you'd have great difficulty harming people with 1mm shot even at the ranges that Posleen prefer to fight.

[Connor MacLeod]

Near as I understand it velocity plays a huge role in how a bullet (normal bullet) interacts with the target. For RL materials 3-4 km/s seems to be the minimum velocity for making explosive craters in material with projectiles, but tens of km/s will definitely do it (like with asteroid impacts.)

Modern tank rounds and the proposed "future" rounds actually go between 1.5-2 km/s as "ideal" for penetration exactly for that reason... although the highest "future" velocity I saw was 2.5-3 km/s (more towards the lower limit.)

I suppose 1mm railguns might avoid the exploding thing by just opting for the lower end of "hypervelocity" - unless you're being super-scientific or adopting what seems to be the strictly military definition, "HV" can go as low as 1-1.5 km/s for small arms or tank guns. Either would owrk fine for a 1mm railgun.

Shotguns might use a sabot of some kind to ensure the firing of 1mm ammo. Sabots would improve their velocity and penetration (especially with chemical propellant) and you would want to be firing a sabot out of a smoothbore anyhow (I think the Steyr ACR was smoothbore, and that's basically what I am describing here. Shotguns have been known to use flechette rounds IIRC as well.)

Frankly I suspect the Posleen weapons fire flechettes or darts rathr than pellets. That would be better from a penetration angle.

[Simon_Jester]

Hmmm. I wonder what the ballistics are like. Maybe the rounds tend to break up on impact, cratering against concrete rather than penetrating but causing vicious wounds? Or do we have 'through-and-through' injuries on humans shot by 1mm rounds?

Unclear. Good thought though, I'd sort of assumed the rounds were either that tiny (being only 1mm) or Ringo just had next to no idea what a railgun was.

Presumably they are tiny rounds, though they may be very long, slender darts... and yet if they were, you'd expect better penetration characteristics.

Emphasis mine, not from the actual briefing, but the helpful flash cards put out by Galtech to teach recognition of Posleen weapons and vehicles. Interestingly, there are 25 cards despite there being, to my knowledge, 8 weapons, 2 vehicles, and 4 ships. Anyways, I doubt there's any insight on the flash cards that wasn't imparted to the ocnference that made the flash cards.

There may be minor variants. Or flash cards representing the same thing from different directions, even- you want to be able to know a Lamprey when you see it from any angle, and not mistake it for something else.

Al, the God-king flying the C-Dec Mike blows in Hymn, reacts to his son's violent death by recalling his forces protecting the grounded ships, including his armor, and lifting off. Also established use of stasis pods in Posleen intersteallar travel. I had wondered how they kept the companies from slaughtering each other out of boredom.

Hmmm. The tenaral may be an adapted version of those armored units- one that no one is accustomed to seeing the Posleen field except immediately around a grounded ship.

[Tasoth]

I guess this is a good thread to ask the question. Isn't there an upper limit to the speed of a round fired in an atmosphere before friction from air particles just turns it into a gout of flame? All the C fractional weapon speeds in an atmosphere make me wonder if you'd really be hitting anything with something other than a big gout of flame.

[Ahriman238]

There may be minor variants. Or flash cards representing the same thing from different directions, even- you want to be able to know a Lamprey when you see it from any angle, and not mistake it for something else.

I can dream can't I? Seriously, as much as it would be cool to have a lot more to the Posleen than we're shown, we can't really debate on the grounds of things that aren't shown.

I guess this is a good thread to ask the question. Isn't there an upper limit to the speed of a round fired in an atmosphere before friction from air particles just turns it into a gout of flame? All the C fractional weapon speeds in an atmosphere make me wonder if you'd really be hitting anything with something other than a big gout of flame.

Huh, flashback. Way back when the thread started Simon said that the grav-guns go so far past the point of vaporization, they'd be more like a spray of cosmic rays. My personal understanding of the subject is that the point of total vaporization shifts greatly depending on the mass of the object in question.

[Simon_Jester]

I guess this is a good thread to ask the question. Isn't there an upper limit to the speed of a round fired in an atmosphere before friction from air particles just turns it into a gout of flame? All the C fractional weapon speeds in an atmosphere make me wonder if you'd really be hitting anything with something other than a big gout of flame.

Yep. Exactly true.

I guess this is a good thread to ask the question. Isn't there an upper limit to the speed of a round fired in an atmosphere before friction from air particles just turns it into a gout of flame? All the C fractional weapon speeds in an atmosphere make me wonder if you'd really be hitting anything with something other than a big gout of flame.

Huh, flashback. Way back when the thread started Simon said that the grav-guns go so far past the point of vaporization, they'd be more like a spray of cosmic rays. My personal understanding of the subject is that the point of total vaporization shifts greatly depending on the mass of the object in question.

It does and it doesn't.

The problem is that per atom kinetic energy of a projectile at 0.1c is so high that any possible force holding the atoms together is negligible.

Imagine that I take a bunch of steel balls and hold them together with toothpicks, then boost them up to 1000 miles an hour and slam them into a wall. For all practical purposes, the toothpicks might as well not be there- they don't have the structural strength to affect what happens when steel hits wall at a thousand miles an hour. I might as well have fired those steel balls out of a cannon as grapeshot, really.

The same happens, on the atomic and subatomic level, with a 'solid' impactor traveling at relativistic speeds.

[PeZook]

I guess this is a good thread to ask the question. Isn't there an upper limit to the speed of a round fired in an atmosphere before friction from air particles just turns it into a gout of flame? All the C fractional weapon speeds in an atmosphere make me wonder if you'd really be hitting anything with something other than a big gout of flame.

Yep. Exactly true.

Wouldn't HVMs also shed unimaginable amounts of energy into the atmosphere as they rapidly accelerated to a fraction of lightspeed?

Wouldn't that cause fun effects like blast waves and superheating the air around the shooter into plasma and stuff?

[Ahriman238]

The smallest, most common Posleen ship is called a lamprey. It is a pentagon in shape, roughly 100 meters in length/width. On the dorsal side is a single powerful anti-ship weapon, but light antipersonnel weapons can be found on all sides. What the anti-ship weapon is, tends to be random, at least two weapons used are quad-plasma batteries and scaled-up HVMs. Terawatt lasers, normal HVMs and plasma cannon make up the secondary weapons. A lamprey usually carries a single company, but can even carry the large 600 strong companies, so could conceivably carry a normal and an under strength company. Lampreys are the most commonly used (though still rarely) for airmobile and air support missions. They have all the same autotargeting capabilities of a tenar, plus the ability to destroy artillery, so does the next ship.

The next biggest fish is the C-Dec, or Command Dodecahedron. A C-Dec has anti-ship weapons on eleven sides, with only the side it lands on bare. C-Decs contain room for 4 companies of Posleen, and a little armor support. They have limited factories for producing weapons, ammo, and ‘everything needed to build civilization on the worlds they conquer.’ They have antimatter production capabilities, and are the only confirmed source of antimatter among the Posleen, though it is impossible to discount ground-based factories for this purpose. C-Decs have cyro-sleep units for their companies, and unlike lampreys possess FTL drives.

When 12 lampreys latch onto a C-Dec (and just why did you think they were called lampreys?) so they can be carried to other star systems, they form a unit known as a B-Dec (Battle Dodecahedron) the preferred unit for space combat. The lampreys cover most, but not all of a facet of the C-Dec, thus they act like an extra layer of armor, and double the number of anti-ship weapons on a side (the regular weapons being part of the C-Dec not covered by the lampreys.) This is also the reason behind the brigade formation. The battlemaster of the C-Dec demands a price for carrying 12 companies with him to a new world. Sometimes this price takes the form of a flat rate payment, or a tax on all their conquests and spoils, or they agree to be his subordinates for this new campaign. In any case, the ships all land fairly close to each other and act in concert. Very often the battlemaster will keep his veteran companies, with the most advanced weapons and/or armor back as a reserve and to provide security for the grounded ships. Scoutmasters, the most junior of God-kings are generally used as cannon fodder.

When traveling in mass, 500-600 B-Decs can link up to form a combat globe. It’s not entirely clear why they do this, the individual B-Decs are all FTL capable, and usually the first thing they do in a serious space fight is break apart and swarm the opposition. Maybe it’s to make sure roughly 4 million Posleen all go to the same planet and hit more or less the same region.

The Galactics utilize energy shields on their spacecraft, at this point there is no evidence the Posleen do the same.

[CaptainChewbacca]

I think they link up to conserve energy while traveling through hyperspace. The posleen don't use the 'ley line' system that the Galactics use, but instead burrow through subspace in an energy-intensive brute-force method, so that's a reasonable explanation to me.

[Ahriman238]

So how do the Posleen stack up against the many and varied alien races and future governments we'd pit them against?

Well, at base, the Posleen are the vast alien swarm, the human wave attacks of the Bugs, Orks, and 'Nids. Somewhat different in that they don't employ the tunneling tactics of the Bugs and 'Nids, and that every member of the host has a ranged weapon. Plus the amount of insane heavy wepaons they have, and the ability to shoot down all enemy aircraft and/or missiles. This will do a lot to help them against airpowers like Renegade Legion. While the ability to casually kill most armored vehicles or megafauna will stand them in good stead in most scenarios. The EMP grenade, if not a one-off, could also be a serious detriment to some armies.

The Posleen can move almost as quickly as mechanized infantry in open country, but are at a signifigant disadvantage in more restricted terrain. They breed faster than even many of the other human wave aliens, are NBC resistant, and can sometimes even learn from their mistakes. Plus, they have some really wanked out wepaons, even if they're mostly shit at real ranges. This makes them fairly dangerous, even to advanced civilizations, though thye're not going to threaten the Culture, Xelee or the Time Lords anytime soon.

Space combat is a lot fuzzier. The Posleen never demonstrate any sort of shielding tech, and only light nuke-equivalent weaponry. On the other hand, Posleen ships generlaly only come in two sizes, hundreds and thousands, and as on the ground they will swarm and pull down most foes with numbers and determination alone. Plus they don't have artificially restricted fields of fire, which is worth a lot of points in my book. And they have magnificent anti-fighter capability, so fighter swarms will not pose much of a problem.

The primary weaknesses of the Posleen are their lack of mobility in difficult terrain, their lack of logistics for long campaigns without much foraging, their lack of understanding the fundamentals of their tech (especially spacecraft) and over reliance on automatic systems. Plus that their God-kings are usually pretty exposed to fire, though they do always move about, and without them the normals are pretty helpless. They will slaughter most air-centric powers, and generally do very well against armor and mechanized infantry. Infantry that entrenches will last longer and inflict better casulties, but will still be dragged down by numbers in the end. The best bet against them is a strong artillery-centered approach, though even that has trouble killing enouhg of them to prevent swarming.

[CaptainChewbacca]

Well, even by the end of the Ringo-Verse stories they were getting ships like Lexington-III, which was capable of one-shotting battleglobes. I think a Star Wars level of power should handle them nicely.

[Ahriman238]

I think they link up to conserve energy while traveling through hyperspace. The posleen don't use the 'ley line' system that the Galactics use, but instead burrow through subspace in an energy-intensive brute-force method, so that's a reasonable explanation to me.

It's certainly possible.

Well, even by the end of the Ringo-Verse stories they were getting ships like Lexington-III, which was capable of one-shotting battleglobes. I think a Star Wars level of power should handle them nicely.

Yes, with 'spinal hypercannon' that are mot likely some sort of larger more refined grav cannon. Given how insane the ground based version is, I actually wouldn't be suprised if the hypercannon were more powerful than turbolasers.

And even if a Star Destroyer could casually destroy a globe, how well can it cope with 600 swarming B-Decs? 2400? 38,000?

[Mr Bean]

And even if a Star Destroyer could casually destroy a globe, how well can it cope with 600 swarming B-Decs? 2400? 38,000?

Accelerate, maneuvers, hyper out. The SD has a much better agility than the globes since it can simply run away and come back as needed as long as it's not in a gravity well which is much more of an issue for ships that have to land all the time in pesky gravity wells.

Even that the LTL on the ship by Shiva standards are enough to blow right through a C-Dec let alone a Lamprey and they are design for high rates of fire for shooting at fighters soo.... the MTL and HTL are able to as well. 600 swarming B-Decs are just so many targets if they can't penetrate the shields. And if they can then they are going to be nasty in close fights.

[Ahriman238]

And even if a Star Destroyer could casually destroy a globe, how well can it cope with 600 swarming B-Decs? 2400? 38,000?

Accelerate, maneuvers, hyper out. The SD has a much better agility than the globes since it can simply run away and come back as needed as long as it's not in a gravity well which is much more of an issue for ships that have to land all the time in pesky gravity wells.

Even that the LTL on the ship by Shiva standards are enough to blow right through a C-Dec let alone a Lamprey and they are design for high rates of fire for shooting at fighters soo.... the MTL and HTL are able to as well. 600 swarming B-Decs are just so many targets if they can't penetrate the shields. And if they can then they are going to be nasty in close fights.

Maybe. I think you make a bit too much of the tactical abilities of SW hyperdrive. I seem to recall during the Thrawn trilogy they were wondering how Thrawn kept pulling off precise tactical jumps until they noticed there was an Interdictor near every emergence point. I also think that gravity wells are probably larger than you think.

However, I'm not going to contest it. The Posleen would probably be hard-pressed to take the Empire in space, or even completly outmatched. Now what's the next step down? I imagine there's a couple before you reach Trek, which I see the Posleen devouring with relish.

The most frustrating thing is having no numbers regarding FTL. We have rough travel times from eath to Diess and Barwhon, but we don't which stars they are. We know roughly how fast Posleen FTL is... compared to the Galactics. It really does make a huge difference in these debates. Hells, we know it took the Posleen almost 200 years to conquer the lump of Galactic space they have, including 74 worlds. But we have no idea how big an area that is.

[Ahriman238]

When the ACS was first designed Mike said they needed a unit that could pass through difficult terrain, move faster than the Posleen in all cirsumstances, survive hundreds or thousands of hits from Posleen weaponry, put out enough firepower to kill them in the millions, and call down precise artillery fire. For the most part, they succeeded.

The ACS is an odd system, at once designed for a very specific form of warfare, but with some amazing general capabilities. Certainly they are amazingly mobile. When it comes to running, the suits can do 32 kph as a sort of brisk jog that can be kept up for hours, 64 kph as a ‘maximum sustainable speed.’ They can also “skitter,” what they call a sprint where the user lets his legs go limp and the suit does the running. Standard suits can thus run at 100 kph at least for short distances. Mike’s super-suit can do double that. They can, with a brief running start, jump over gaps more than 100 meters across. For a trivial amount of power, the suit anti-grav will kick in and preserve altitude at the apogee of one’s leap, for a little while. This same system lets them fall most any distance and be fine. The suits can also fly at speeds up to 129 kph, 400 kph for Mike’s suit. The standard suits can only fly for about 10 minutes before running out of juice, but even 30 seconds of flight time is invaluable in getting over or around obstacles. Not that it should be needed that often, because thanks to the “universal clamps” in their glove palms and boot soles, ACS troopers can make like Spider-man. The suits once or twice get where they need to go by walking a river or lake bed.
The ACS has a cable and winch system, rated to either 10,000 kg or 1,360 depending on one’s interpretation. The ‘cable’ which is really more like a bit of string in thickness, is a full kilometer long. This is presumably meant for suit recovery, but it opens up whole new worlds of navigating and manipulating their environment.

Not much is said about the physical strength enhancements of the suit. They’re clearly there, but seldom remarked upon or quantified. In the first chapter of Eye there’s a line about suit “pseudo-muscles that could drive an armored fist through 3 inches of homogenous steel.” On another occasion, in Dance, an ammo-less suit unit started picking up and throwing/rolling ‘man-sized’ boulders at the enemy.

The armor itself is made of one of those unique sohon substances, uranium and silicon bonded into a single molecule. What properties that will have, I have no idea. Mike’s super-suit is 60 mm thick, but is probably even thicker than the already reinforced command suit, so no luck with hard numbers besides an upper limit. This is further backed up a form of forcefield, ‘energetic enhancement.’ They also exploit a lot of inertial-dampening, mass-lightening and momentum redistribution tech to survive all manner of impacts. From stepping off a kilometer-high building to getting thrown out of a truck at highway speeds, enduring nuclear blast waves, to getting fired at the ground by a hypersonic shuttle at treetop heights. But apparently there is concern that the suits might be damaged by uncontrolled rappelling and slamming into objects at 10 m/s. They can even weather a point-blank barrage of railguns, including heavies, by reducing the suits mass to a couple grams and letting them get carried away by the impact. The suits are mirrored to reflect away as much of a lasers energy as possible. It sort of works, sometimes.

Suits are normally impervious to ‘any terrestrial weapon short of a nuke,’ and Posleen shotguns and light railguns. They can sometimes resist the fire of plasma weapons and heavy railguns, almost always die when targeted by terawatt lasers and invariably die when hit with HVMs.

The suits also have personal forcefields, PFFs, and personal area-fields, PAFs. The PFF surrounds them with a 12 meter circle, the PAF does the same thing with a wall. Though impervious to bullets, the fields offer barely any protection from railgun rounds and none from HVMs. They are meant primarily as a defense against plasma and laser fire, conveniently two of the most popular weapons in other types of science fiction. Though the ability of the forcefields is somewhat questionable and inconsistent.

Even if something penetrates the armor, as long as it doesn’t immediately kill the user and doesn’t critically hurt the heart, brain or spine, the suits medical suite can keep the user alive and probably even combat effective. Wounds are immediately cleaned, and a local anesthetic applied. A soldier can lose a hand and be back to firing in just a moment, and with regeneration tech he can get fixed up when the fighting is over. The suits also have reservoirs of two major Galactic drugs; Hiberzine, which puts a person into suspended animation for up to 3 months, and Provigil-C, a stimulant that lets someone go for 3 days without sleep with no degradation to their mental facilities or serious side effects, at least when it’s properly mixed. In the post-war world there’s apparently a roaring black market trade in Provigil-C.

[Ahriman238]

Now we come to a problem, because the M-300 grav-rifle, the standard weapon of the ACS, is insane. It seems to exist solely to disprove the old military saying that there’s no such thing as overkill. In fact, if we take the most conservative, low-end figures and quarter them, what we’d have would still be moderately impressive for a tank gun. If we use the high-end figures… we get a couple of chainguns that shoot baby nukes, to represent one grav-rifle. So, we’ll go with the low-end figures. With those we have a gun that shoots rounds the equivalent of 100 lbs of TNT at a rate of 30,000 rounds per minute. Enough to kill tanks, and butcher large squads of infantry, enough to gut medium-sized buildings, with a single shot. With AID computer-targeting, the ACS can make a perfect hit with every shot, even from 2 km away. In fact, the only reason they don’t have a perfect accuracy rating is that they normally fire a lot more shots than there are targets. The suits carry over 9,000!! (specifically 900,000) rounds, enough for a full half-hours sustained fire. Or pretty much indefinitely on single-shot mode.

A sniper variation also exists, though it is basically the same weapon without the automatic fire, and with considerable technology employed to mask the energy spike of firing. The ACS troopers also carry sidearms, grav-pistols with 4,500 rounds apiece, also capable of casually making headshots from 2 km distance.

The suit grenade launcher has gone through some changes. In the first book, the shoulder-mounted launcher could drop a grenade with pinpoint accuracy anywhere within 1,200 meters, and carried at least 300 grenades. The grenades themselves are antimatter bombs with ‘the power of a 120mm mortar’ that more or less level anything within 15 meters, with a soft kill radius of 35 meters. The grenades can be used by hand as well as fired by the launchers. Now, in Hell’s Faire the grenades are the same, or so I assume from the similar stats, but the suits now mount twin launchers and a 3,000 meter range. Good on them, I suppose.

The standard ACS trooper also carries on him 4 kilos of C-9 an ‘atomic catalyst explosive,’ cratering charges that are normally used to make instant foxholes, but prove themselves very handy for improvised demolition work as early as the first book, and at least 5 Suicide Bars (or “subars”) adjustable yield antimatter grenades (though I’m really skeptical about the supposed mechanism for adjusting them) that scale from a few kilos of TNT equivalent to 11 tons of TNT. In short, the ACS tends to be very well supplied with things that go boom.

All of these reflect the abilities and loadout of the standard suits called Warrior suits in the first book and Marauder in the last. There are additional varieties: scout, command, engineer/medic, and Reaper. To say nothing of Mike’s one of a kind super-suit.

Scout suits are more lightly armored than the standard suit, but are faster and stealthier, with specialized sensor gear the standard suits do not have, and the sniper-pattern grav-rifle. The sensor tools include remote sensor balls, “fly-eyes” and sensor wands far more sensitive than the suits’ own sensor units. We don’t know a ton about the sort of sensors used by ACS, but the basic package contains, at a minimum- thermometer/thermal detector, sonar, lidar, and a Geiger counter. The suit has over 70 visual options, the default allows a uniform light level even when in perfect darkness, increased peripheral, near and long vision. The suit stealth systems, which everyone has, uses holograms to create an ‘invisibility cloak’ effect by projecting an image of whatever is one their other side. At the same time, the suits energy shield sets itself to warp radar and other forms of detection, and a ‘subspace field’ move the air in such a way that there’s no obvious displacement when the suits move fast or ‘holes’ in the air currents when they are still.

The suits holographic capabilities are useful for more than just stealth. They can also display decals and emoticons. Seriously though, the suits sometimes employ ‘psychological refinements,’ holographic illusions used to make an ACS unit seem more powerful and intimidating rather than letting them go unseen. Like turning every suit into a squad of suits. Or turning a company into a many-headed dragon, that one is used 3 times over the course of the series. Or even making every individual suit appear as a 4 meter tall demon. These illusions sometimes make it hard for even the Posleen to charge, and even offer some protection, since it’s hard to tell where the suit is inside the image, or even if the suit is in there as opposed to hunkering under cover nearby.

Command suits are one of the things we know next to nothing about, just enough to have an idea how much we don’t know, really. We know they have twice as many functions as standard suits, but not what most of them are. We do know they are more heavily armored, and have 3 times the power supply to support the vast number of command and control programs and options they have. They are also modified to be even more survivable, on the theory that their users are more valuable. Command suits are issued to every officer. Command suits are armed with the standard grav-rifle, grenade launcher, and grav-pistol sidearm. Command suits can access visual and sensor feeds from other suits, compile data from suits and remote sensors into a 3-d mini-map, and project a ‘will o the wisp’ on subordinates helmet displays to lead them down complicated routes. Any or all of these may be common suit abilities. The only ones we know are unique to the command suit are the ability to participate in high-level conference calls, break into the calls of their subordinates, and remote control tripod mounted heavy weaponry, which they abandoned after Diess anyway. Because of their superior power, command suits can fly longer, jump further, etc.

A note here, I am slowly reading Eye of the Storm online, and I have seen a line about the armor material of ACS being theoretically tougher than neutronium. In fact, Michelle says that the warships only have a very thin layer of the ACS material reinforcing their armor, because it would take too much time and expense to armor them completely with it.

Moving on, the Engineer suit is the same as the standard but with thinner armor, and many extra compartments. Enough to make the suits look ‘like grapes’ with arms and legs, and carry an extra 100 kg of explosives. Engineering suits are not armed, except with grav-pistols. This same suit variant is used by medics and suit technicians, who use the extra storage space to carry the tools and supplies of their trades.

The Reapers are the heavy weapon troops of the ACS, and after their introduction the tactics and doctrine of the entire ACS increasingly revolves around them. The Reapers are thinner armored than the standard, and pot-bellied in appearance. This is because of their greater ammunition capacity. The Reapers trade in their grav-rifles and grenade launchers for four hardpoints (each shoulder and forearm) that can mount a variety of weapons. On Diess, the Reapers mounted 75mm mortars and operated tripod-mounted terawatt lasers and ‘heavy grav-guns.’ However, in the field the mortars proved inferior to the standard grenade launchers, the lasers exploded, and the ACS decided they relied too much on mobility and shock tactics to have much use for tripod weaponry. So the design process for Reaper weapons was even more rushed than the rest of GalTech.

For all that, they seem to work well enough. The primary ranged weapon is a 60mm mortar with a range of 8 kilometers. Within that range, it can drop its rounds with millimeter precision. It has 14 different types of rounds including standard HE rounds compatible with ordinary mortars, cluster bombs, and antimatter charges that tend to level anything less tough than suits within an 8 km radius. Most of the ammo types are unknown. Despite carrying at least hundreds, likely thousands of rounds, the mortars can run themselves dry in just 20 seconds of constant firing, though they will be a very unpleasant 20 seconds for the enemy.

Close-in weapons include ‘super-shotguns’ also with a wide variety of ammo types, flechette cannon, and an unnamed third weapon. The flechette cannon is a 12 barrel gatling-gun style weapon, that fires 40,000 steel darts a minute, and seem to also be a form of railgun. The Reapers can carry enough ammunition to keep the flechette cannon fed for 6 minutes of constant firing. Keep in mind that Reapers only mount one form of weapon at one time, so that’s ammo for 4 cannon, which is what anyone fighting the Reapers would face. So 960,000 rounds.

Finally, the Reapers have a 75mm grav-gun variant for fighting landers. It’s actually almost halfway to being an HVM, since it also uses an onboard engine. For what it’s worth, in their one use in the book they accelerated only to 1,000 km/s by the time they hit the lander, and that was only enough to breach its outer armor and destroy exposed weapons. This weapon fires 5 shots a second, and the Reaper can carry 100 rounds. There is also a throwaway line about ACS using plasma cannons, which if true probably means the Reapers. They also at one point use ground based AM lance missiles (the same ship-killer missiles as the Space Falcon) as anti-lander SAMs, and the weapons are entrusted to the Reapers.

The major weaknesses of the ACS are mostly logistical. The suits allegedly have battery power to operate for 300 miles or 3 days, but in practical terms it’s a lot less, and that without the ‘firing grav-guns from suit power’ thing. And even the massive amounts of ammunition they haul around can get exhausted, considering they were designed to maximize RoF while fighting the numberless alien hordes. The suits can maneuver a wide variety of terrain, and bring a lot of hurt down, but they will ultimately lose almost any contest of attrition. It takes a sohon master either a month or 6 (conflicting numbers again) to make a suit, and there are only about 1,000 sohon masters in the entire galaxy. It takes at least 100 hours in a suit to synch up with it enough to move when you want and stop when you want and not make the world spin around when you try and look to the side. Thousands of suit hours are required to make a suit ace. At least one afternoon of ACS training is entirely spent taking nauseates and practicing vomiting in the suits, so they understand on every level that they will never drown in their ejecta. What I’m saying here is, it takes a very long time to replace combat losses. There is a line about heat dispersal being a problem, but nothing specific and it is never mentioned again. Of course, the grav-guns remain insane and physics-defying, but for the moment we’ll accept them, this is for debates.

[Simon_Jester]

A note here, I am slowly reading Eye of the Storm online, and I have seen a line about the armor material of ACS being theoretically tougher than neutronium. In fact, Michelle says that the warships only have a very thin layer of the ACS material reinforcing their armor, because it would take too much time and expense to armor them completely with it.

I don't buy "tougher than neutronium." But I do buy "only a thin layer of ACS material-" remember the manufacturing technique. As I said before, I'm pretty sure that any material made that way by Sohon adepts will be inherently difficult to make and will require a fixed investment of adept man-hours per kilogram of material. Putting a thick layer of ACS material over the surface of a (very big) warship will take a lot of tons.

Since the ship is already going to be huge and heavy, neither mass nor volume is a critical constraint. Whereas both are issues for a platform that needs to be able to perform infantry missions. So swapping out a centimeter of ACS material for ten centimeters of other materials that are, taken together, just as strong and way cheaper actually works, where it wouldn't work for powered armor.

Finally, the Reapers have a 75mm grav-gun variant for fighting landers. It’s actually almost halfway to being an HVM, since it also uses an onboard engine. For what it’s worth, in their one use in the book they accelerated only to 1,000 km/s by the time they hit the lander, and that was only enough to breach its outer armor and destroy exposed weapons.

Oy.

At 1000 km/s, the kinetic energy of an impactor is roughly one kiloton per kilogram; a multi-kilogram 75mm projectile at those speeds should hit really goddamn hard. If it's not penetrating when SheVa rounds can, it's got to be because the hypervelocity impactor simply bursts on contact, without actually punching into the material, because material doesn't have time to get out of the way.

This would also have implications for other hypervelocity weapons used on Posleen ships, and may help to explain why grav rifles are ineffective against them even after you hit them with thousands of rounds.

[Ahriman238]

"Tougher than Neutronium" is pretty disingenious, seeing just how many things penetrate the suits over the years.

As for the 75mm grav-guns, we don't really know that they're multi-kilogram or even a single kilogram. But yes, they fire 1200 rounds onto a single patch of hull the size of a human hand. It breaches the armor and rips up the insides some, but does not seem to destroy or even mission kill the ship. The other ACS have to coup de grace it by pouring their own fire into the hole.

[Simon_Jester]

1200 of the things should have a combined impact on par with a big nuke- the amount of directional energy going into the hull should exceed that from O'Neil's patented Nuclear Backpack Trick, even given that the backpack was fixed to the hull.