Worldbuilding: Mil Sci fi/fan feedback

[Steelinghades]

This thread I'm designing to outline my ideas and thoughts about a military science fiction/fantasy series, of which I've been sporadically posting story pieces of over the last while on both spacebattles and sufficient velocity, and seeking some feedback over what people think regarding it. I'm mixing this up a bit, since I don't have a bunch of time to go super into detail for a bit, I'm going to pick pieces out of the story itself and then go into greater detail about certain points mentioned.



For a bit of OP reader interaction, if there's a part from the below story--which I'll be adding to soon--you were wondering about, here's where I go into greater, sometimes too much, detail about it, so just ask.



The story itself for those wondering:
https://forums.sufficientvelocity.com/t ... ory.41856/ <- SV version
https://forums.spacebattles.com/threads ... ry.568627/ <- SB version

The USS Excalibur

USS stands for Union StarShip.

That was only because most colony worlds couldn't afford to outfit their ships with actual kinetic weapons—railguns, coilguns, mass driver, accelerators, etc—or ordnance weapons. Thus they used energy weapons, which allowed them to avoid having to spend a large amount of their GDP on ammunition.

Mainly becuase of the fact that unlike energy based weaponry--and more esoteric designs--a kinetic or ballistic weapon requires far more upkeep to the weapon system, ammunition needs to be bought and tested, etc. Compared to energy weapons wherein none of that is of concern; an energy based weapons costs more outright, but kinetic or ballistic costs more in the long run.

And there's always the issues of crew training and skill. Using a kinetic or ballistic weapon in solar warfare requires quite a bit of skill and knowledge of various factors of solar combat that for an energy weapon or self guiding weapon aren't that big of a consideration.

“Captain,” Lieutenant Markus Laernin, sensors officer, said. “We have just left the celestial shadow zone, we may engage Starjump drives at any time.”

The CSZ is both a physical and metaphysical concept. Gravity as we known it is changed within the outer skins of astral space, taking on a number of weird properties that can cause a rather large amount of damage, both physical and mental, to a starship crew. Not only does being in Astral space and within a CSZ cause a frenzy of a sort to begin to gnaw at everyone's mind, there are beings that live within a Celetrial Shadow Zone that would love to devour a staeship or two--most of the time, the gibbering things don't even notice there were sapient beings wihtin. Not to mention that if you get too close to a CSZ center it's more then likely to just crush you.

It's not technically impossible to jump through a Shadow Zone, indeed starships do it all the time by worming through a planet's shadow zone. A fighter capable of going FTL however will fall to a planetary CSZ, starships have enough mass and powerful enough shielding to bypass safely. With that in mind, scientists believe if you were to build a vessel of great enough mass and shielding, you could bypass a star's Shadow zone, but building such a massive construct is not remotely practical currently.

tearing open a hole in space-time to enter Etherspace-1.

The official scientific term for Astral space is Etherspace-1, which means Etherspace first layer, the deeper into Astral space you went, the higher the number. However it's always a bad idea to dive deeper into Etherspace/Astral space as those that have tried have never returned.

Etherspace-1 is the official term for the warping lanes used to traverse the galaxy, however if you were to talk to the more arcane minded folk, they wouldn't be caught dead using the term Etherspace, they always use Astral space.





That's all for know, feel free to ask questions or make observations.

[Sea Skimmer]

Mainly becuase of the fact that unlike energy based weaponry--and more esoteric designs--a kinetic or ballistic weapon requires far more upkeep to the weapon system, ammunition needs to be bought and tested, etc.

This argument is rather sensitive to details, unguided ammunition for a rail gun for example could cost almost nothing in military terms, while a large coil gun launched guided projectile containing multiple nuclear warheads might be more like a fighter plane then a missile is in cost today.

The shipboard impact is also a big deal, lasers and particle beams cooling requirements in particular become a big problem in space where you don't have the ability to cycle seawater or air as coolant. Using your own propellant tanks is appealing. In general maintenance for laser and particle beam weapons is likely to be much more expensive and difficult to carry out.

Compared to energy weapons wherein none of that is of concern; an energy based weapons costs more outright, but kinetic or ballistic costs more in the long run.

Depends on how much you actually shoot. History is full of people simply buying weapons with little ammunition. If people are on a budget in space they'll do the same. The bigger question is what the weapons can actually do, people will buy the most effective weapons they can because if they look like they built a military on a budget too much they are much more likely to need it.

And there's always the issues of crew training and skill. Using a kinetic or ballistic weapon in solar warfare requires quite a bit of skill and knowledge of various factors of solar combat that for an energy weapon or self guiding weapon aren't that big of a consideration.

Doubt training will really matter on this, space combat will be largely decided by computers and unguided KE weapons would never have an effective range past maybe a thousand kilometers if that, which makes it very unlikely they'll be a primary armament. No matter what you do space warships will require highly trained crews, but the total number of people will be very small compared to planetary populations.

Of course you could still get inept space navies, but that isn't likely to be a design basis.

The real question is would KE weapons have any validity at all as primary ship to ship armaments.

[Steelinghades]

Mainly becuase of the fact that unlike energy based weaponry--and more esoteric designs--a kinetic or ballistic weapon requires far more upkeep to the weapon system, ammunition needs to be bought and tested, etc.

This argument is rather sensitive to details, unguided ammunition for a rail gun for example could cost almost nothing in military terms, while a large coil gun launched guided projectile containing multiple nuclear warheads might be more like a fighter plane then a missile is in cost today.

There's also the cost of shipping them light years out to where ever they would be needed; most colonies are small--a couple hundred thousand to a million or two--and don't have the industry to fully support a starship; certainly not the fuel buy also the ammunition. Planets that have the industry to produce their own equipment for ships will have a mix of weapons like full on nations.

The real question is would KE weapons have any validity at all as primary ship to ship armaments.

Depends on what the ship is meant to do, ships designed around extreme range warfare will only be armed with missiles and other ordnance weapons along with lasers. Ships designed for close range will have more slower weaponry that packs more of a punch, plasma and EM guns.

As for which weapons are better in what circumstance, energy weapons are better at range--compared to kinetic--have the speed on their side and are superior against shields. Kinetic weapons are better at close range and can punch through armour far better then energy weapons. Ordnance weapons have their abilities of self guidance as their advantage.

[KraytKing]

The shipboard impact is also a big deal, lasers and particle beams cooling requirements in particular become a big problem in space where you don't have the ability to cycle seawater or air as coolant. Using your own propellant tanks is appealing. In general maintenance for laser and particle beam weapons is likely to be much more expensive and difficult to carry out.

Now, correct me if I'm wrong, but it was my understanding that the generally low temperature of space made cooling pretty much a non-factor.

[Simon_Jester]

Quite the opposite. Space isn't "cold" in the sense that, say, Antarctica is cold.

It's "cold" in that you can radiate away heat until your temperature drops to -270 degrees Celsius and nothing will stop you, as long as you're not in direct sunlight.

The catch is that in space, you're not touching any air or water or solid surfaces that conduct and convect heat away from you. So the only way to lose a surplus of heat energy is through radiating it away, which is very slow and inefficient. Heat built up by doing something with the machinery on your ship will have to be slowly radiated away over time, and the most likely way to do this fast (big radiator panels) means you have big floppy fragile structures attached to your ship, which isn't great in a combat zone.

[KraytKing]

Interesting. Is it at all practical to bleed a small amount of gas over the hot parts to pull away heat before disappearing into space?

[Formless]

No. IIRC, you would have to bleed far too much of your coolant in terms of mass for it to be worth it compared to simply putting bigger radiators on the ship. If specific parts of the ship get particularly hot, you can simply run cooling systems over them internally, but you want to limit the amount of coolant you lose to space whenever possible (obviously, a space fighter will always risk losing coolant due to battle damage). On the bright side from an aesthetic perspective, this justifies spaceships having wings despite the common knowledge that they aren't pushing off of atmosphere like airplanes do.

However, there is a kind of radiator called a liquid droplet radiator where the coolant is temporarily exposed to space in a manner similar to a fountain and then recollected for further use. But its still a type of radiator, and not necessarily better than other types. It can be resistant to battle damage, depending on the design, as projectiles will simply pass through the fountain and drag a minimum amount of coolant with it, while the spray nozzle and collector can be pretty tough machinery if designed right. There is a long standing myth among Hard SF geeks that conventional radiators cannot be armored, but its just a matter of either making them thicker at the cost of making them less efficient, or making them out of hard transparent materials such as IR grade quartz or even diamond. They are a weak part of any realistic spacecraft design, so that makes it all the more imperative to find ways of defending them or making them more resistant to battle damage.

[Shroom Man 777]

If you don't want to get too tangled up in the details or spell out something that you might later find inconvenient and end up rationalizing stuff, you could keep them in your head or in "off-screen" Silmarilion/Legendarium-esque notes to maintain verse-consistency without having to provide too much details to readers/viewers. Like your hyperdrive mechanics or ordnance preferences.

Like, in-universe it could be shown that for some colonies, energy weapons are preferred, or for ships certain patterns and such for FTL are used, and it's obvious that there are in-universe reasons for that even though the narrative doesn't detail it. I mean, for example, we could talk about how a modern ship sails to port without outright detailing how it took a certain rout to dodge coral reefs (real-life equivalent to your celestial shadow zones), or that hemp rope was phased out and replaced with other kinds of rope because of blah blah reasons drug war etc. We can say that as Jack Sparrow had the Black Pearl dock at Tortuga, he used satellite navigation without specifying how GPS is preferred because the Russian GLOSNASS grid is incomplete because Roscosmos' satellite delivery services have been lagging because of several Soyuz failures whereas the US GPS is well-maintained because Melon Usk's SpaceXXX partnered with Pornhub and so the new line of phallic space rockets doing orbital refueling with vaginal space docks and astronauts/pilots stimulated by livestream porn get better orbital navigation performances cumulatively resulting in superior orbital logistics and GPS satellite replacement ratios that only the Chinese can match with their giant orbital Foxconn factories that are surrounded by carbon nanotubule netting to prevent suicidal space employees from jumping to their deaths via orbital reentry. THEN some Space Foxconn Space Employee does Space Suicide that the net doesn't catch, the jumper crashes into a satellite and breaks it and the resulting conflagration causes orbital debris to spew all over the place, wrecking Space Sandra Bullock's shuttle and resulting in her being marooned in spaaaaace! See, hard sci-fi right there baaabaaaay!

[Simon_Jester]

Interesting. Is it at all practical to bleed a small amount of gas over the hot parts to pull away heat before disappearing into space?

You could do it briefly as an emergency measure to cool down systems that are only used for a short amount of time, which actually might make sense during battle. But it would, effectively, be another limit on your ship's endurance. Just as aircraft can only stay in the air for so long before running out of gas and falling out of the sky, so a ship that expends coolant to keep its internals from overheating can only fire its high-energy weapons and engines for so long before the interior bakes.

[Sea Skimmer]

There's also the cost of shipping them light years out to where ever they would be needed; most colonies are small--a couple hundred thousand to a million or two--and don't have the industry to fully support a starship; certainly not the fuel buy also the ammunition.

That's kind of just reason why they'd have no locally funded space going military at all, for the same reason Bermuda doesn't have nuclear submarines. But if it came down to it you could make unguided KE ammo with a foundry, machine shop and supply of iron and copper, the later for the armature winding. It's pretty damn simple. Meanwhile nearly anything in terms of spare parts for a laser is going to be vastly more difficult to manufacture.

Again though, what is militarily effective in the setting is what counts first. And in all probability very small colonies would have mobile ground based defenses rather then anything in space, because it'd be much cheaper and more importantly it'd have some kind of survivability and deterrence value not found in very weak warships that can be spotted from very long range.

Depends on what the ship is meant to do, ships designed around extreme range warfare will only be armed with missiles and other ordnance weapons along with lasers. Ships designed for close range will have more slower weaponry that packs more of a punch, plasma and EM guns.

Why would you intentionally design a close range ship? You can always carry more nuclear missiles with shaped charge warheads for close range work on the long range ship. This is kinda literally why battleships died off. How tactical is the FTL system?

Plasma makes very little sense as a weapon in space BTW, probably anything you are thinking about 'plasma' wise amounts to magic of one form or another. Which is fine but keep in mind you should come up with a rough idea of what it's supposed to do, since it's not gonna be very science based.

As for which weapons are better in what circumstance, energy weapons are better at range--compared to kinetic--have the speed on their side and are superior against shields. Kinetic weapons are better at close range and can punch through armour far better then energy weapons. Ordnance weapons have their abilities of self guidance as their advantage.

It really wouldn't be an either or situation on that; because if the bore of the KE gun is at least five inches then we already know we can fire a existing tech nuclear weapon out of it, and mr nuke produces both KE effects and a range of thermal and radiation effects out of hand, and some plasma even! A pure fusion bomb in principle might be much smaller if you have the power technology to trigger it in a small package. But I do really doubt KE weapons would be useful offensively except as the first stage for missile like projectile. A weak colony ship with KE weapons just doen't sound very worthwhile. I suppose though it also depends on how much sci fi we have to use here though. Nothing strictly limits the muzzle velocity of an EM gun, it just becomes really impracticable with real life materials after a point.

Also don't forget about particle beams, they make more sense then lasers for a lot of roles but will tend to be a lot more complicated too. But the tech for high end railguns and particle accelerators and lasers all overlap to some degree.

[Steelinghades]

That's kind of just reason why they'd have no locally funded space going military at all, for the same reason Bermuda doesn't have nuclear submarines. But if it came down to it you could make unguided KE ammo with a foundry, machine shop and supply of iron and copper, the later for the armature winding. It's pretty damn simple. Meanwhile nearly anything in terms of spare parts for a laser is going to be vastly more difficult to manufacture.

While there's also the reason I'll mention below for the third reason, but in essence there are three reasons.

1: Energy weapons are easier to use, less taxing in the long run on manufacturing, cost and such.
2: A system defence militia is only really around to discourage pirates, slaves and marauders and their ilk. Thus they don't really need armour breakers since the most likely foe they'll come across doesn't have armour and in that circumstance energy weapons are the better option.
3: The third reason is that they don't have the devices that allow them to work with kinetic weapons properly and use them to their full potential, more detail below.

Again though, what is militarily effective in the setting is what counts first. And in all probability very small colonies would have mobile ground based defenses rather then anything in space, because it'd be much cheaper and more importantly it'd have some kind of survivability and deterrence value not found in very weak warships that can be spotted from very long range.

Ground based forces are the last military force a planet would buy, without planetary shielding systems to make invasion difficult and bombardment practically impossible there's nothing stopping an invading force from dropping a few nukes onto your ground forces bases.

Why would you intentionally design a close range ship? You can always carry more nuclear missiles with shaped charge warheads for close range work on the long range ship. This is kinda literally why battleships died off. How tactical is the FTL system?

The FTL system itself isn't tactical, but there are systems that use the same systems FTL uses to cruise around at high speeds; they're not FTL since none of them exceed the speed of light, with the fastest--warp--moving at the speed if light. These systems are useful when moving to the engagement or running away but not for constant use in combat since shielding system shut off during the transit. And for the faster ones it fully merges into Astral space so you can't see what's happening in real space. Ships generally have to remain away from each other when warping since if not they get suckered together. What's stopping an enemy ship from warping toward your artillery ships is that most ships have a system they can activate that will generate a warp field, holding a ship back.

Plasma makes very little sense as a weapon in space BTW, probably anything you are thinking about 'plasma' wise amounts to magic of one form or another. Which is fine but keep in mind you should come up with a rough idea of what it's supposed to do, since it's not gonna be very science based.

It's not actual plasma, the real term--shortened from its full name--is plasm, short for plasmium. It's called plasma in universe because of its similar appearance in some cases to actual plasma.

[Simon_Jester]

That's kind of just reason why they'd have no locally funded space going military at all, for the same reason Bermuda doesn't have nuclear submarines. But if it came down to it you could make unguided KE ammo with a foundry, machine shop and supply of iron and copper, the later for the armature winding. It's pretty damn simple. Meanwhile nearly anything in terms of spare parts for a laser is going to be vastly more difficult to manufacture.

While there's also the reason I'll mention below for the third reason, but in essence there are three reasons.

1: Energy weapons are easier to use, less taxing in the long run on manufacturing, cost and such.
2: A system defence militia is only really around to discourage pirates, slaves and marauders and their ilk. Thus they don't really need armour breakers since the most likely foe they'll come across doesn't have armour and in that circumstance energy weapons are the better option.
3: The third reason is that they don't have the devices that allow them to work with kinetic weapons properly and use them to their full potential, more detail below.

Did you not read what the man said? Energy weapons are not necessarily less taxing on manufacturing. Complex machines require spare part supply whether they use ammunition or not, and reactors require fuel. There is no reason to just assume that the long term upkeep cost of a laser cannon are lower than those of a cannonball cannon; certainly that's not the way things seem to be trending in real life.

Again though, what is militarily effective in the setting is what counts first. And in all probability very small colonies would have mobile ground based defenses rather then anything in space, because it'd be much cheaper and more importantly it'd have some kind of survivability and deterrence value not found in very weak warships that can be spotted from very long range.

Ground based forces are the last military force a planet would buy, without planetary shielding systems to make invasion difficult and bombardment practically impossible there's nothing stopping an invading force from dropping a few nukes onto your ground forces bases.

Did you not read the word "mobile?" The point here is for the weapons to be used only against enemy ships that approach the planet into practical range, to discourage the smallest and weakest raiders. No tiny colony with a negligible industrial base is going to be able to afford spacegoing warships likely to defeat a serious attack fleet, and it's almost certainly wasteful of resources to try. So instead, have ground defenses to stop a bunch of goons in a battered old Firefly-class transport from taking over the planet with one ship, and rely on the navy's regular patrols, or your own colony's obscurity, to discourage anyone bigger from coming your way.

Plasma makes very little sense as a weapon in space BTW, probably anything you are thinking about 'plasma' wise amounts to magic of one form or another. Which is fine but keep in mind you should come up with a rough idea of what it's supposed to do, since it's not gonna be very science based.

It's not actual plasma, the real term--shortened from its full name--is plasm, short for plasmium. It's called plasma in universe because of its similar appearance in some cases to actual plasma.

So it's a made-up bullshittium substance? If so, don't give it a name identical to a real substance and act surprised when people assume it is the real substance.

Like, if I tell you that my character is going to headbutt his way through an iron wall, you'll tell me that's foolish. If I reply "wait, it's not really iron, it's iorn, a substance that looks just like iron but is actually soft and squishy like butter," you will still be within your rights to stand by your earlier description.

[Stewart M]

Thus they used energy weapons, which allowed them to avoid having to spend a large amount of their GDP on ammunition.

If you'll forgive a petty style criticism, the term "GDP" sounds weird here. Maybe use "resources" or "budget".

Though as others have mentioned, unless your ammunition is hydrogen warheads or something, I doubt your bottleneck would be price. I can imagine that energy weapons might be more compact than projectile weapons, with several engagements worth of ammo taken into account, and that might be reason enough to favor them on spacecraft and certain installations. That would depend on how exactly the laser is fueled.

And there's always the issues of crew training and skill. Using a kinetic or ballistic weapon in solar warfare requires quite a bit of skill and knowledge of various factors of solar combat that for an energy weapon or self guiding weapon aren't that big of a consideration.

For the record, I would consider crew skill (or computer programming or whatever) for energy weapons to be a big consideration. Even in a future where lasers are a well-tested commodity that don't require specialists to maintain, lasers are affected by gravity, and at stellar distances, those few degrees (radians?) might make all the difference. Plus, there's diffraction (especially important when firing through an atmosphere or gas cloud). In fact, we're already seeing an arms race in laser vs. missile tactics in real life, whether it be coating the missile in reflective materials or making it spin so the laser can't concentrate its beam on a certain point.

I'm not saying your point is wrong. Ballistic weapons are probably more complicated, but I wanted to add these details for the record.

---

My far-out hard SF idea is if there is a setting where spacecraft are clumsy (slow acceleration and turning), and armor tech is modest (more helicopter than 19th century battleship), and scanning/targeting hardware is difficult to fit on a cheap projectile, then projectile space combat for poor combatants will evolve to favor 'grapeshot' rounds, attacking cones of space to compensate for the inaccuracy of interplanetary targeting and the diminishing value of course corrections communicated from firing platform light-minutes away. If a handful of 5mm shrapnel traveling at .0001c relative to target can wound a spacecraft, then it should be simple enough to pollute a few cubic kilometers of space with a salvo of cheap-ish artillery rounds. Even if the shrapnel doesn't hit anything crucial (and there's isn't much non-crucial on a spacecraft), it will force the crew to pause their mission until they can patch the little holes. Sooner or later, they'll run out of patches.

Naturally, tactics will evolve to provide dramatic tension. For an easy, short-range shot, set the 'fuse' to create a narrow, dense cone, producing a small 'kill zone' but excellent odds to hit if the target passes through. Likewise, for a distant shot against a nimble target, set the fuse to a wide burst, producing a generously-sized kill zone that's iffy on the "kill".

[Steelinghades]

Did you not read what the man said? Energy weapons are not necessarily less taxing on manufacturing. Complex machines require spare part supply whether they use ammunition or not, and reactors require fuel. There is no reason to just assume that the long term upkeep cost of a laser cannon are lower than those of a cannonball cannon; certainly that's not the way things seem to be trending in real life.

If the weapons and ammunition were being produced from the same planet as the ship is guarding, then yes this would be correct. However once shipping costs come into it along with price for actual kinetic rounds--which I should have mentioned earlier have at least partial guidance and maneuvering thrusters and sometimes main thrusters for extra speed--then the costs start to spiral up.

Did you not read the word "mobile?" The point here is for the weapons to be used only against enemy ships that approach the planet into practical range, to discourage the smallest and weakest raiders. No tiny colony with a negligible industrial base is going to be able to afford spacegoing warships likely to defeat a serious attack fleet, and it's almost certainly wasteful of resources to try. So instead, have ground defenses to stop a bunch of goons in a battered old Firefly-class transport from taking over the planet with one ship, and rely on the navy's regular patrols, or your own colony's obscurity, to discourage anyone bigger from coming your way.

[Sea Skimmer]

If a handful of 5mm shrapnel traveling at .0001c relative to target can wound a spacecraft, then it should be simple enough to pollute a few cubic kilometers of space with a salvo of cheap-ish artillery rounds. Even if the shrapnel doesn't hit anything crucial (and there's isn't much non-crucial on a spacecraft), it will force the crew to pause their mission until they can patch the little holes. Sooner or later, they'll run out of patches.

For very small ships that might work out. Call it 15 grains at 29,979 meters per second would mean a muzzle energy of 438,170 joules, and it's going to vaporize on impact making armoring against it much easier then projectiles that would remain intact. Classic whipple shield job. It's also going to mean a defensive laser doesn't have a very hard time vaporizing the incoming round; and it only needs to vaporize enough to deflect the ones that are going to hit the ship. The defensive fire control system knows the future intended course of the ship while the offensive system does not. This is a big limitation of all small-fast weapons in a space context.

Also got to keep in mind the target ship could already be moving a lot faster then 30km/s relative speed, and mount missiles with much higher delta vee budgets. Since reasonable detection ranges could be like.... earth to moon kind of distances the effectiveness of a weapon like this is very sensitive to certain details, and hard sci fi hardly rules out heavily armored ships. How much money people really have is one of those key details.

[Stewart M]

If a handful of 5mm shrapnel traveling at .0001c relative to target can wound a spacecraft, then it should be simple enough to pollute a few cubic kilometers of space with a salvo of cheap-ish artillery rounds. Even if the shrapnel doesn't hit anything crucial (and there's isn't much non-crucial on a spacecraft), it will force the crew to pause their mission until they can patch the little holes. Sooner or later, they'll run out of patches.

For very small ships that might work out. Call it 15 grains at 29,979 meters per second would mean a muzzle energy of 438,170 joules, and it's going to vaporize on impact making armoring against it much easier then projectiles that would remain intact. Classic whipple shield job. It's also going to mean a defensive laser doesn't have a very hard time vaporizing the incoming round; and it only needs to vaporize enough to deflect the ones that are going to hit the ship. The defensive fire control system knows the future intended course of the ship while the offensive system does not. This is a big limitation of all small-fast weapons in a space context.

I did not know about Whipple shields; that is a serious flaw in my idea.

I also assumed that a setting low-tech enough to validate burst artillery would not have mounted point defensive lasers so precise, but that may be overly pessimistic on my part.

... the effectiveness of a weapon like this is very sensitive to certain details, and hard sci fi hardly rules out heavily armored ships. How much money people really have is one of those key details.

True. I admit that I tend to assume the most costly bit of spacecraft will always be the cost of lifting weight into orbit and that armor is necessarily very heavy. But I could see several hard SF scenarios that alleviate either assumption.

[Formless]

I did not know about Whipple shields; that is a serious flaw in my idea.

I also assumed that a setting low-tech enough to validate burst artillery would not have mounted point defensive lasers so precise, but that may be overly pessimistic on my part.

In fact, lasers as point defense is so probable that even civilian vessels might have a form of them called a "laser broom" intended to reduce the danger of debris in low Earth orbit as well as Kessler Syndrome. Its really not that hard to make a laser, there are tons of ways to do so. The main issues are efficiency, cooling, and raw power, but it probably doesn't take much to deflect debris or projectiles less massive than a soda can. Hell, a ship's radar system might incorporate maser technology, and with enough output I could see even microwave emissions being useful for deflecting some debris. A maser could even be a ship to ship weapon in its own right, as microwave emissions are absorbed by metals and can fry electronics. Lasers have a bigger wow factor for most people, though, so their microwave emitting predecessors are often forgotten even by hard science fiction fans.

[Simon_Jester]

If the weapons and ammunition were being produced from the same planet as the ship is guarding, then yes this would be correct. However once shipping costs come into it along with price for actual kinetic rounds--which I should have mentioned earlier have at least partial guidance and maneuvering thrusters and sometimes main thrusters for extra speed--then the costs start to spiral up.

If shipping costs for a bunch of ferrous slugs with guidance packages are that crippling, interstellar space travel itself is cripplingly expensive, and fighting space wars makes no economic sense. There can't be any credible commerce or trade, and shipping passengers or by extension colonists would be prohibitive. For that matter, delivering the mass of a defensive spaceship itself would be prohibitive!

[Stewart M]

I did not know about Whipple shields; that is a serious flaw in my idea.

I also assumed that a setting low-tech enough to validate burst artillery would not have mounted point defensive lasers so precise, but that may be overly pessimistic on my part.

In fact, lasers as point defense is so probable that even civilian vessels might have a form of them called a "laser broom" intended to reduce the danger of debris in low Earth orbit as well as Kessler Syndrome. Its really not that hard to make a laser, there are tons of ways to do so. The main issues are efficiency, cooling, and raw power, but it probably doesn't take much to deflect debris or projectiles less massive than a soda can. Hell, a ship's radar system might incorporate maser technology, and with enough output I could see even microwave emissions being useful for deflecting some debris. A maser could even be a ship to ship weapon in its own right, as microwave emissions are absorbed by metals and can fry electronics. Lasers have a bigger wow factor for most people, though, so their microwave emitting predecessors are often forgotten even by hard science fiction fans.

Very interesting. Thank you.

[Sea Skimmer]

I also assumed that a setting low-tech enough to validate burst artillery would not have mounted point defensive lasers so precise, but that may be overly pessimistic on my part.

At that point the width of the beam helps the accuracy issue and is something you can vary on a laser slightly; but pointing will be very precise either way. Look at the Hubble telescope pointing accuracy for its ultra long range shots, 7/millionths of a degree IIRC, using thrusters and gyroscopes to move the entire thing no less to do it and keep it on target while orbiting the earth. While a spacecraft will still have some vibrations from its engines and possibly weapons firing/being hit in action, overall you've got a way easier dynamic environment to work with then on a plane or ship where the weather is constantly screwing with your stabilization. You do have way more thermal stress to deal with, but that's pretty well understood at this point, it's just part of why space anything costs lots of money. Its also a place long term where costs would go down.

True. I admit that I tend to assume the most costly bit of spacecraft will always be the cost of lifting weight into orbit and that armor is necessarily very heavy. But I could see several hard SF scenarios that alleviate either assumption.

Once you start mining in space for one thing, armor mass may become very cheap. If you aren't mining in space, one might ask why you even have space warships. Other thing to consider is a large portion of any remotely hard spacecraft will be fuel tankage. That lends itself to using the fuel tanks as a whole lot of spaced armor. You might spill a lot of fuel in action, but whatever, a tanker can resupply you after the battle.

It does in the end matter a great deal how many resources you have. Million ton space warships are certainly feasible with real technology just as they would be on the earth's surface if anyone reallllly cared, but it doesn't mean they'd ever have reason to get built.

[Sea Skimmer]

1: Energy weapons are easier to use, less taxing in the long run on manufacturing, cost and such.

Again, that does not jive with reality. EM guns are easier to engineer then lasers, let alone more exotic forms of directed energy devices like particle accelerators. That's why we can build railguns today that would sink battleships while lasers are at the shoot down a 1914 biplane level of perfection, or else chemically powered monstrosities that could never have provided sustained fire. Rule of thumb, smaller and faster is going to be harder then bigger and slower.

2: A system defence militia is only really around to discourage pirates, slaves and marauders and their ilk. Thus they don't really need armour breakers since the most likely foe they'll come across doesn't have armour and in that circumstance energy weapons are the better option.

That doesn't support the idea that ammunition would be a significant problem then. If you aren't expending it the cost is more or less fixed, which is largely how naval weapons have always worked. Transport isn't an issue, the ship carries its basic load of ammo from the shipyard and that is that. Since this is space anything you fire in training can be recovered and reused, exactly like exercise torpedoes in real life. Easier actually, since in real life sometimes you still loose exercise torpedoes. Real life navies generally only have 1 load of ammo per ship (if that) in the first place and it's pretty much always been that way outside of the world wars.

Again I expect a free electron laser to be a better weapon anyway, but not for the reasons you are giving.

Ground based forces are the last military force a planet would buy, without planetary shielding systems to make invasion difficult and bombardment practically impossible there's nothing stopping an invading force from dropping a few nukes onto your ground forces bases.

Nuclear weapons by definition would be something you can shoot down with ground based defenses. Without some kind of ground based defense any colony is highly vulnerable to covert attacks, and things like the enemy landing on the far side of a planet and then attacking by aerodynamic craft or similar. Anyway the whole point is you can disperse a huge amount of firepower on the ground for very low operating cost as a deterrent. If the enemy is just going to nuke the colony that only increases the need for some kind of terminal defense.

Also if all warfare is nuclear by default then you might want to think about just why it is some poor not able to defend itself colony exists at all, and why it in't being protected by some kind of stronger government. Operations like mining will require very few people in the future, if any at all ect...

It's not actual plasma, the real term--shortened from its full name--is plasm, short for plasmium. It's called plasma in universe because of its similar appearance in some cases to actual plasma.

I think Corona Juice would sound better if you ever write anything story wise... Plasma is so blah.

[Sky Captain]

Aren't some of the reasons why shipboard laser weapons are considered in real life to not to have to waste limited supply of expensive missiles or CIWS ammo just to shoot down a cheap attack drone swarm? In this case "set biplane on fire" level of output is good enough.

[Formless]

Actually, Steelinghades, plasma weapons of a sort might just be plausible, and there are researchers who were working on the problem even as late as 2009 and as early as 1993 with the now classified MARAUDER project. They would essentially fire toroids of plasma held together by their own electromagnetic fields-- or in other words, weaponized ball lightning. Notably, MARAUDER was supposed to be able to shoot (very light) projectiles at thousands of kilometers per second, up to 3% the speed of light even. Though the project is now classified, the technology crosses over with the kind of technology that might someday allow fusion reactors to produce surplus power. I've been considering making a thread of my own on the subject to detail what plausible ranges and effects you might expect such weapons to achieve. Mostly it appears that thermal and electromagnetic effects are what they wanted to achieve (especially in space), and in atmosphere they might be able to disrupt the airflow around aircraft and missiles. Whether they will have any significant kinetic effects I don't know, as there is very little information about MARAUDER online let alone Promethius II. How much range you can expect is debatable, since the last statements by the private researchers said they were still having issues achieving long term/long range stability out of a foot wide vortex. But in theory, it might be significant especially if those velocities really are achievable. Also, research into ball lightning that has come about in the meantime suggests that actual ball lightning events might have to do with vaporized silicon and other solid conductive materials. So a plausible plasma weapon won't necessarily fire a purely gaseous projectile. You might have a "magazine" of very easy to obtain silcon or even just sand.

If I understand correctly, the weapon might look and operate something like this.

IMO saying that your weapon is an offshoot of lightning research might still be handwavium, but at least gives it an aura of plausibility and grounds the idea better than going the Star Wars rout of naming a weapon after something it clearly isn't (i.e. lasers in Star Wars clearly aren't lasers, and what you are doing is much the same). For instance, Gene Roddenberry originally wanted the Enterprise to fire maser weapons, but then decided to rename the weapons Phasers so that when he inevitably screwed up the physics of real masers no one could call him out on it. He also replaced the hand lasers from the first pilot with hand phasers for the same reason. Paradoxically, if your weapon is based off of handwavium people will more readily accept it and suspend disbelief in it if you give it a name indicating that it is in fact a handwave.

Alternatively, if you want a plasma weapon that doesn't need possibly unobtainable properties like ball lightning guns, nuclear shaped charges would very likely create hot jets of plasma extending over tens of kilometers. If you want to focus mostly on the kinetic and thermal properties of the nuclear blast and leave out all the icky radiation stuff (which is slightly unavoidable as all nuclear explosions create X-Rays and neutron flux), it turns out it might be possible to create a pure fusion bomb. Basically, you have a series of staged chemical explosions that cause a phenomenon called an overdriven detonation which squishes a tritium core between two flier plates moving at 8 or more kilometers per second. The whole thing looks like a big gun, but you might actually point the gun "backwards" because all the reaction byproducts of the chemical explosives will absorb x-rays and instantly turn into a jet of superheated plasma. So its got a built in shaped charge aspect to it. The physicist who designed it estimated that you can only scale it up to a maximum of 2 kilotons TNT equivalent, but in your setting such weapons might be more politically acceptable for use in space or even on ground due to the fact it uses no fissile materials and creates basically no fallout in an atmospheric detonation. Any colony that can make TNT and obtain tritium could make this weapon, so if the physics are correct it should be very achievable (scarily so, even, for the real world implications). They won't need a nuclear breeder reactor that would violate nuclear-nonproliferation treaties. And of course, you can also make nuclear pumped x-ray or gamma-ray lasers with this kind of weapon as well. Maybe even nuclear-kinetic shaped charges. So there is versatility in going this rout.

[Steelinghades]

If the weapons and ammunition were being produced from the same planet as the ship is guarding, then yes this would be correct. However once shipping costs come into it along with price for actual kinetic rounds--which I should have mentioned earlier have at least partial guidance and maneuvering thrusters and sometimes main thrusters for extra speed--then the costs start to spiral up.

If shipping costs for a bunch of ferrous slugs with guidance packages are that crippling, interstellar space travel itself is cripplingly expensive, and fighting space wars makes no economic sense. There can't be any credible commerce or trade, and shipping passengers or by extension colonists would be prohibitive. For that matter, delivering the mass of a defensive spaceship itself would be prohibitive!

For a full on star nation, the costs are minimal but for a planetary militia who gains the majority of their budget from the rich nobles and aristocracy on the planet it does get expensive.

Nuclear weapons by definition would be something you can shoot down with ground based defenses. Without some kind of ground based defense any colony is highly vulnerable to covert attacks, and things like the enemy landing on the far side of a planet and then attacking by aerodynamic craft or similar. Anyway the whole point is you can disperse a huge amount of firepower on the ground for very low operating cost as a deterrent. If the enemy is just going to nuke the colony that only increases the need for some kind of terminal defense.

Planetary defenses only really exist on shielded worlds who can have full on proper space defence systems. Without things like a planetary shield there is nothing a planetary weapons system CA do against an enemy warship that decides to sit far outside their own range and bombard them to hell and back. And if a bunch of--say, slavers--were to come along and fine a planet that has gone full on with their ground based defences they won't approach, they'll just grab a small asteroid and throw it at the planet and scavenge from the remains ground side.

Also if all warfare is nuclear by default then you might want to think about just why it is some poor not able to defend itself colony exists at all, and why it in't being protected by some kind of stronger government. Operations like mining will require very few people in the future, if any at all ect...

Stronger nations do defend smaller colony worlds--the story itself above involes a star empire sending along some extra defenses--they simply cannot defend everything. And generally colonies can defend themselves against their most likely threat--pirates and other raiders--even if their own ships aren't up to the task the can always hire mercenaries.

As for nuking, I was using it more as an example of why unshielded world's don't have large ground side military forces. An example of a thing a starship can do to a planet with impunity. Bombing runs from fighters, kinetic impactors or precision DEW strikes, etc.

[Formless]

So, uh, I was wondering-- this sounds like a Science Fiction topic and setting, yet you have put the thread in the Fantasy forum. At first I thought it was a mistake, but now that you mention that things like planetary shields exist in the setting, I must ask-- are you even intending this to appeal to Hard SF sensibilities, or is this thread really intended to run through the internal logic of a Space Opera style setting? Because if so, that changes the discussion significantly. I think there may be some unspoken assumptions about the genre of this story that may need to be stated before this can go anywhere productive, because Skimmer is kinda not the guy to talk to about Soft SF.