Space Warfare - How would the ships be built/designed?

[Azimech]

Defense against lasers: just point mirrors at your enemy.

Laser warfare would be primarily a battle to dissipate heat, on both sides. Damage the cooling system of your opponent and you've almost won.

[baggers]

Isn't a "guided projectile" just a "spacecraft"? And a railgun is just an alternate way of putting it on an intercept than a cheap, regular rocket stage!

Just rename your railgun a "electromagnetic catapult" ond you're on ^^

[baggers]

As to guided railgun shots, those use lifting surfaces to perform terminal guidance in the RL concept, so you know, I don't know how good that would work for you in space... If they used rocket engines, they would be missiles. And never mind they still need a targeting system, if they are missiles they can be exploded with pathetically weak lasers.

The difference between a "missile" and a "guided railgun projectile" is obvious: a railgun projectile carry only cinetic energy, a hardened point and core and a relatively small RCS or ion engine for trajectories corrections at the back, protected by the hardened point and core.

A missile carry : initial big rocket AND RCS engines AND explosives. A defensive laser can destroy any of the engines, or even worse, detonate the explosive charge.

A railgun projectile don't need to carry a rocket or bunch of explosives. The initial speed given by the railgun catapult goes for it.

So, no, I don't think a railgun guided projectile will be as weak as a regular missile.

. Firing a railgun to a moving target behind a planet is an absurdly bad idea, BTW. Think about the orbital dynamics a minute, you who I assume plays KSP...

Let's assume a submarine on earth armed with a railgun. It can shot prograde or retrograde and hit any orbit, no problem. And it has stealth on top of that!

Edited September 16, 2015 by baggers

[Jouni]

Whether or not Europe increased military spending before World War 2 (my history books disagree) is irrelevant to the fact that Europe clearly didn't have enough troops and spent a bunch of their funds on the wrong things (such as the Maginot Line). The entire reason I brought up World War 2 in the first place was to point out that Europe was caught completely off-guard. Just as you will be, next time a major war involving Europe breaks out. Just because the Cold War is over does NOT mean its tactics (and its weapons) are obsolete.

You have a really misguided view of WW2, if you think it as Europe vs. Germany. Fascism was a big thing in the 1930s in most of Europe (and in the US), and many countries willingly sided with Germany, because they were obviously the good guys.

UK, Netherlands, and Belgium were caught off-guard. France spent the entire interwar period rearming itself and building alliances with the newly created countries against Germany, because they had a long history of fighting each other. Denmark didn't really want to fight against Germany, while Norwegians fought effectively for months. The Baltic states, Poland, Yugoslavia, Albania, and Greece were effectively surrounded by much greater hostile powers. The rest of continental Europe was either neutral or sided with Germany.

There were many reasons why the French lost so quickly:

• The French believed that tanks and infantry should support each other, while the Germans used tanks as a separate force. The German approach worked better in the early WW2, while the French approach proved superior towards the end of the war.
  
• France just lacked the manpower. Their population was already much lower than in Germany, and they had also suffered higher casualties in WW1.
  
• Germany just happened to outmaneuver France. Such things happen in a war.
  

Under different circumstances, they could have put up a good fight, but the luck was not in their favor.

Yes it does. Because the Russians have one very important piece of military hardware, that Europe does not.

A backbone.

Inferior weapons can (and currently do) pose a huge threat if the people staring up the barrels are afraid to shoot back.

You know, I come from a small European country bordering Russia. From a country where Russia has always been the main focus of both foreign and defence policy. A country where most men still serve in military. A country that actually has more tanks than Germany, despite having less than 7% of the population. A country that carefully follows the developments in Russian politics, economy, and society. A country that watched with great interest how Russia fought in Chechnya, Georgia, and Ukraine.

Russia can't beat any major European power in conventional warfare, because it lacks the economic backbone to fight a major war.

If my political goals included conquest? Absolutely. Tanks for the win. Plus supporting infantry and air power. The reason most of the world thinks otherwise is because most of the world isn't trying to conquer the rest of it. The one entity that is (hint: it's in the Middle East, and it starts with an "I") is an army of morons who don't know how to drive/repair/maintain tanks.

Conquest is a pretty stupid goal these days, when real power comes from trade and economy. Russia demonstrated that quite nicely by conquering parts of a country nobody really cares about, almost destroying itself in the process.

Aha! Thank you for reminding me. That's another good military tactic: give your opponents a big, scary target that they will waste firepower on, while ignoring the flank maneuver coming in on their side......

The enemy with superior tanks can also use every tactic you describe, with the main difference being that their tanks are less fragile. As a result, you always risk higher casualties than the enemy trying the same tactic.

[Scoundrel]

Some interesting assumptions.

Defense against lasers: just point mirrors at your enemy.

Mirrors aren't 100% reflective; even dielectric mirrors don't ever quite reach a true 100% - plus they have to be designed for a certain wavelength or it becomes destructive rather than reflective. Thus a pulse laser - rather than the continuous wave laser that most people assume would be weaponized - coupled with the ability to adjust its wavelength even just a little, would quickly make a bunch of highly absorptive black marks on the mirror that would cause it to overheat and melt.

So yes, it would be effective... unfortunately only for a short period.

The difference between a "missile" and a "guided railgun projectile" is obvious: a railgun projectile carry only cinetic energy, a hardened point and core and a relatively small RCS or ion engine for trajectories corrections at the back, protected by the hardened point and core.

There's not much point in a small RCS (and especially no point in a tiny ion engine) in a projectile at the velocities we're talking about. Sensor inaccuracies alone would dictate any firing solution be at ranges close enough that RCS on a projectile would be pointless.

In fact anti-starship railguns are more likely to carry proximity laser fused explosive tungsten continuous rod warheads due to their ability to cut things in half. A direct hit with one would be nothing short of spectacular (large portions of the ship would simply disintegrate), whereas a near miss would result in much less dramatic but no less effective similar catastrophic damage. It would also be equally as impressive in the anti-missile role as it would in the anti-swarm role. Its use as a direct hit kinetic weapon would likely be a tertiary use of the weapon.

As for hitting something in other orbits: just because you can lob a projectile fast enough to intercept an orbit the planet/moon's SOI doesn't mean the projectile becomes captured. There's a reason there's a capture/insertion burn after a vessel is in the Mun's SOI.

Now, an area denial weapon that uses a railgun to put it in orbit could have an explosive or fuel-type "charge" with enough delta V to put a cloud of particles in the anticipated path of a target (we are assuming the target's orbital path can be predicted because it isn't drunkwalking). If the projectile wasn't detected then the target flies into the path of the particles and bad things happen to it. Or the target detects the cloud and adjusts its orbit appropriately.... perhaps into the path of another cloud of particles that hadn't been noticed. The idea being to deplete the fuel of attackers/defenders before the final engagement... or even just to force them into predictable orbits when their delta V budget becomes really tight.

In fact where I really see them shining is when the enemy is attempting to refuel - then you have multiple targets on predictable paths. Just spit out a few area denial shells and watch the two of them constantly adjusting their paths until the warship runs out of fuel and becomes easy pickin's, or the two are committed in an intercept and you take out both the warship and the tanker. Heck, you can do it when they're on the other side of the planet and can't detect the area denial detonations.

Someone should make a mod for that...

[baggers]

In fact anti-starship railguns are more likely to carry proximity laser fused explosive tungsten continuous rod warheads due to their ability to cut things in half. A direct hit with one would be nothing short of spectacular (large portions of the ship would simply disintegrate), whereas a near miss would result in much less dramatic but no less effective similar catastrophic damage. It would also be equally as impressive in the anti-missile role as it would in the anti-swarm role. Its use as a direct hit kinetic weapon would likely be a tertiary use of the weapon.

I could only imagine the amount of space and orbits pollution these sort of weapon can manage! These should be banned by convention! Just imagine a large scale warfare with rod from the first year of conflict still orbiting everywhere and striking random, hunders of years after the end of war! ^^

[Kibble]

The difference between a "missile" and a "guided railgun projectile"

There really is not a difference. Whether you use a rocket stage, a railgun, or a medieval catapult, once it is deployed on an intercept the killer satellite has the exact same requirements. It needs to have all the trappings of any other spacecraft (guidance, communications, power), be somewhat maneuverable, with RCS and a small rocket engine for rendezvous within required range, and an explosive charge (to fragment the satellite into bits). Without the explosives, the rendezvous range required for guaranteed destruction of the target goes from about 1 km, to literally zero inches.

Edited September 16, 2015 by Kibble

[Requia]

Expect sophisticated point defense systems and possibly armour. Don't expect "shields", a sci-fi trope with little basis in reality.

Nah, those are possible, to an extent, sandwhiching plasma between two magnetic fields has a similar effect. Beyond current state of the art to actually hold it, but there's already an anti explosive prototype that works by detecting the explosion before the shockwave hits then pulsing a wave of plasma (also a good option).

Ships won't explode with antimatter either, antimatter doesnt explode. It makes a ton of gamma radiation, that penetrates pretty much anything, so the vast majority of the energy will pass through the ship. It'll kill crew and fry electronics in the process though,

[baggers]

There really is not a difference. Whether you use a rocket stage, a railgun, or a medieval catapult, once it is deployed on an intercept the killer satellite has the exact same requirements. It needs to have all the trappings of any other spacecraft (guidance, communications, power), be somewhat maneuverable, with RCS and a small rocket engine for rendezvous within required range, and an explosive charge (to fragment the satellite into bits). Without the explosives, the rendezvous range required for guaranteed destruction of the target goes from about 1 km, to literally zero inches.

It's more a " very close fly-by" than a "rendez-vous", but I see what you mean ^^

[Requia]

I could only imagine the amount of space and orbits pollution these sort of weapon can manage! These should be banned by convention! Just imagine a large scale warfare with rod from the first year of conflict still orbiting everywhere and striking random, hunders of years after the end of war! ^^

We deal with the same thing with terrestrial battles, WWI claimed its (hopefully) last victim in 1998.

[shynung]

There really is not a difference. Whether you use a rocket stage, a railgun, or a medieval catapult, once it is deployed on an intercept the killer satellite has the exact same requirements. It needs to have all the trappings of any other spacecraft (guidance, communications, power), be somewhat maneuverable, with RCS and a small rocket engine for rendezvous within required range, and an explosive charge (to fragment the satellite into bits). Without the explosives, the rendezvous range required for guaranteed destruction of the target goes from about 1 km, to literally zero inches.

Missile warheads can be much more variable than simple fragmentation charges. A missile could be built to have some sort of single-use ultra-capacitor that burns out after discharge, and have enough stored energy to power many kinds of payloads. Things like mini-railguns that fire kinetic impactors, small laser cannons, EMP generators, or even stuff like asphalt cement ejectors (gunks up exposed sensors, radiators, and solar panels), high-voltage electrostatic nets (shorts out sensors/antennas sticking out), or maybe chemical payloads designed to heavily corrode metals.

In the end, missiles (as in, self-correcting munitions) are just small spacecrafts intended to get close to the target and do things that harm or impair the target. How it actually does it is something that's very flexible, and can be adjusted to counter various types of defensive measures.

[Rune]

I'm more interested in using railguns to deploy disposable sensor platforms designed to have stealth in space at tactical ranges and durations (Active cooling, cold gas RCS, ect) that can get clear of the enemy's laserblind and have their own sensors, tramsmitting back to the mothership.

Alternate versions can mount weapon systems- if they can remained undetected long enough to get into effective Casabla Howitzer range, game over. These arnt Missiles, but they're Torpedos, at least.

Wait, what? Stealth railgun rounds? It's not that, for nth time, there is no stealth in space. As we have seen, railguns right now are about 10% efficient, and could get to maybe 30%. Which means, by the time they leave the rail, they will be screaming on the infrared with the wasted energy, probably glowing to the naked eye. And you want to make that "stealthy". Good luck.

Have the best of both worlds. Launch your guided missiles using a railgun.

That is a dumb suggestion. I mean, really dumb (the suggestion, not you, no personal attack here, just a figure of speech! ). You are suggesting designing missiles that withstand upwards of 20,000Gs and a lot of heat so you can launch them at about ~2.5km/s, when you could put a solid first stage with 250s I_sp and it would do the very same thing.

Isn't a "guided projectile" just a "spacecraft"? And a railgun is just an alternate way of putting it on an intercept than a cheap, regular rocket stage!

Hear, hear! A very complicated and expensive way.

Defense against lasers: just point mirrors at your enemy.

Laser warfare would be primarily a battle to dissipate heat, on both sides. Damage the cooling system of your opponent and you've almost won.

Seriously? I mean, I don't much about lasers, but that's like, the first thing you learn. I encourage you to read scoundrel's answer to this. Basically, mirrors won't work for defense against weapon-grade lasers.

The difference between a "missile" and a "guided railgun projectile" is obvious: a railgun projectile carry only cinetic energy, a hardened point and core and a relatively small RCS or ion engine for trajectories corrections at the back, protected by the hardened point and core.

A missile carry : initial big rocket AND RCS engines AND explosives. A defensive laser can destroy any of the engines, or even worse, detonate the explosive charge.

A railgun projectile don't need to carry a rocket or bunch of explosives. The initial speed given by the railgun catapult goes for it.

So, no, I don't think a railgun guided projectile will be as weak as a regular missile.

Let's assume a submarine on earth armed with a railgun. It can shot prograde or retrograde and hit any orbit, no problem. And it has stealth on top of that!

No missile in space needs an explosive payload, mate. Even the simplest solid chem-missile can reach comparable speeds to a railgun round. Only it doesn't have to be built to withstand 20,000G's and a huge electric arc going through it during launch, which means you can put on it things that aren't solid-state electronics packaged in ultra-hard foam, like a fuel tank.

Now, the sub idea, it's like the third time I see it. An interesting form of MAD, if your railgun is capable of interplanetary shots... only at those scales of war, your sub is just as immobile as a fixed installation. In the interplanetary total war that we seem to be discussing here, I can just threaten to drop enough rocks to significantly evaporate the ocean your sub hides in. Not to destroy the sub, mind you, though it'll probably work for that too: diverting a couple big asteroids ensures that the guys that built the sub also die with your citizens in the exchange of weapons of mass destruction.

An interplanetary missile on the sub would offer pretty much the same level of MAD, just like it would on an underground bunker, only a missile shot would be able to maneuver somewhat to avoid interception during the months of cruise before it hits. And for extra cost-effectiveness, a bunch of small probes attached to hefty asteroids with a small reactor, and a way to use the asteroid for reaction mass, spread throughout space where any attack against them will be clearly seen by your telescopes. Those are probably cheaper to build than a nuclear sub (cost of an ARM mission on a Atlas V vs cost for a Ohio-class sub... I think even a SLS-launched ARM is cheaper than those monsters).

Some interesting assumptions.

Mirrors aren't 100% reflective; even dielectric mirrors don't ever quite reach a true 100% - plus they have to be designed for a certain wavelength or it becomes destructive rather than reflective. Thus a pulse laser - rather than the continuous wave laser that most people assume would be weaponized - coupled with the ability to adjust its wavelength even just a little, would quickly make a bunch of highly absorptive black marks on the mirror that would cause it to overheat and melt.

So yes, it would be effective... unfortunately only for a short period.

There's not much point in a small RCS (and especially no point in a tiny ion engine) in a projectile at the velocities we're talking about. Sensor inaccuracies alone would dictate any firing solution be at ranges close enough that RCS on a projectile would be pointless.

In fact anti-starship railguns are more likely to carry proximity laser fused explosive tungsten continuous rod warheads due to their ability to cut things in half. A direct hit with one would be nothing short of spectacular (large portions of the ship would simply disintegrate), whereas a near miss would result in much less dramatic but no less effective similar catastrophic damage. It would also be equally as impressive in the anti-missile role as it would in the anti-swarm role. Its use as a direct hit kinetic weapon would likely be a tertiary use of the weapon.

As for hitting something in other orbits: just because you can lob a projectile fast enough to intercept an orbit the planet/moon's SOI doesn't mean the projectile becomes captured. There's a reason there's a capture/insertion burn after a vessel is in the Mun's SOI.

Now, an area denial weapon that uses a railgun to put it in orbit could have an explosive or fuel-type "charge" with enough delta V to put a cloud of particles in the anticipated path of a target (we are assuming the target's orbital path can be predicted because it isn't drunkwalking). If the projectile wasn't detected then the target flies into the path of the particles and bad things happen to it. Or the target detects the cloud and adjusts its orbit appropriately.... perhaps into the path of another cloud of particles that hadn't been noticed. The idea being to deplete the fuel of attackers/defenders before the final engagement... or even just to force them into predictable orbits when their delta V budget becomes really tight.

In fact where I really see them shining is when the enemy is attempting to refuel - then you have multiple targets on predictable paths. Just spit out a few area denial shells and watch the two of them constantly adjusting their paths until the warship runs out of fuel and becomes easy pickin's, or the two are committed in an intercept and you take out both the warship and the tanker. Heck, you can do it when they're on the other side of the planet and can't detect the area denial detonations.

Someone should make a mod for that...

I woudl say +1... almost. That "cutting things in half" comment. If there is enough energy in the railgun round to cut something in half, then the laser fed by the same powerplant can also cut things in half, and at a bigger range. And way before that, it can blind the targeting sensors on the enemy, so the enemy won't be able to fire in the first place.

Area-denial weapons like those debris-seeding ideas come into a few problems, too: a) space is big, detection is dumb easy, and c) you only need miligees to sidestep them, considering your reaction time. So maybe if you are fighting a very long war, seeding the enemy's planet orbit with debris will be a viable idea to hurt his economic output... but it'll do nothing in the short term against a particular attack, and we are seeing that space warfare with fixed infrastructures is more akin to MAD, where conflicts that go into that scale pretty much guarantee the death of most civilians on both sides.

And anyhow, the range of laserstars means there won't be enemy combatants around the same rock for long. Either the attacker withdraws, or the defender can force a battle, and may the longest-ranged laser win.

Missile warheads can be much more variable than simple fragmentation charges. A missile could be built to have some sort of single-use ultra-capacitor that burns out after discharge, and have enough stored energy to power many kinds of payloads. Things like mini-railguns that fire kinetic impactors, small laser cannons, EMP generators, or even stuff like asphalt cement ejectors (gunks up exposed sensors, radiators, and solar panels), high-voltage electrostatic nets (shorts out sensors/antennas sticking out), or maybe chemical payloads designed to heavily corrode metals.

In the end, missiles (as in, self-correcting munitions) are just small spacecrafts intended to get close to the target and do things that harm or impair the target. How it actually does it is something that's very flexible, and can be adjusted to counter various types of defensive measures.

Half of those assume you couldn't get a bigger destructive potential with an inert warhead. Since you can, there is little point to build such expensive things. I mean, "chemical payloads to corrode metal"... Seriously?! You are just throwing technobabble there. At interplanetary engagement speeds (or railgun speeds, for that matter), you pack more damage in kinetic energy than what high explosives can give you.

But again, IT'S NOT LIKE MISSILES WILL BE EVER ABLE TO HIT A LASER WARSHIP. For the nth time, a laser can blind anything long before it has any chances of shooting at it with anything, except another laser. Meaning railgun rounds won't find the target to fire at, and missiles won't know where to be guided to. And if they did, somehow, through magic, they could be blown out of the sky by the same laser when they get a bit closer.

Rune. I'm sorry it's boring, and I know railguns sound cool. But they are only good against fixed installations as siege weapons, at most.

Edited September 17, 2015 by Rune

[baggers]

Rune, isn't that you who are speaking about the "Arrow Vs Armor" just before?

That "armor of lasers" will just fall like all of theses at the long run, I bet ^^

- - - Updated - - -

And if you're on the "big war" thing:

Imagine a planet. War comes.

The ships sail. They have railguns, some, big. And ammo. Many ammo.

They shot. One projectile after the other. At a slow pace. Kepping their barrels colds. They fire the entire day. And the entire week. And the entire month. One month after the other. Dozen, hunderds, thousands, millions and billions of railgun guided projectiles.

The projectiles are on their way. They have month, maybe year before reaching the target. From a straigh long line, they slowly adjust pace, regroup. Ultimately form a gigantic swarm.

That swarm of billions and billions of projectiles came at once on the ennemy territories. Like small baby turtles just born on the coast and reaching the oceans full of dangers. The ennemy lasers are everywhere, the ennemy probes take down hunderds, thousands, millions of thems.

But they reach the target: the ennemy fleet, and still are billions.

The ennemy fleet lasers fires, warm, hot, all at once.

But they can do nothing about theses billions, coming in one inarretable swarm. One projectile pass. One ennemy ship is disabled. The fleets lasers start to overheat, some laser start to fire at a slower pace. More and more projectiles pass and reach the ennemy ships. In less than a minute all of them have silently exploded as the swarm passed.

The war is over, in one salvo.

Edited September 17, 2015 by baggers

[Rakaydos]

Wait, what? Stealth railgun rounds? It's not that, for nth time, there is no stealth in space. As we have seen, railguns right now are about 10% efficient, and could get to maybe 30%. Which means, by the time they leave the rail, they will be screaming on the infrared with the wasted energy, probably glowing to the naked eye. And you want to make thst stealthy?

Sure. Use an insulated sabot to do the acceleration, then decelerate the hot sabot so it dpesnt reveal the torps vector. Put directional radiators on the recon torps- what the enemy sensor platforms 5 light minues away report is irrelevant if the torp can change vector even slightly with cold gas thrusters. Passive sensors and a maser comunicator, to avoid betraying emissions toward the source of the mothership's laser blindness.

[Frozen_Heart]

Rune, isn't that you who are speaking about the "Arrow Vs Armor" just before?

That "armor of lasers" will just fall like all of theses at the long run, I bet ^^

- - - Updated - - -

And if you're on the "big war" thing:

Imagine a planet. War comes.

The ships sail. They have railguns, some, big. And ammo. Many ammo.

They shot. One projectile after the other. At a slow pace. Kepping their barrels colds. They fire the entire day. And the entire week. And the entire month. One month after the other. Dozen, hunderds, thousands, millions and billions of railgun guided projectiles.

The projectiles are on their way. They have month, maybe year before reaching the target. From a straigh long line, they slowly adjust pace, regroup. Ultimately form a gigantic swarm.

That swarm of billions and billions of projectiles came at once on the ennemy territories. Like small baby turtles just born on the coast and reaching the oceans full of dangers. The ennemy lasers are everywhere, the ennemy probes take down hunderds, thousands, millions of thems.

But they reach the target: the ennemy fleet, and still are billions.

The ennemy fleet lasers fires, warm, hot, all at once.

But they can do nothing about theses billions, coming in one inarretable swarm. One projectile pass. One ennemy ship is disabled. The fleets lasers start to overheat, some laser start to fire at a slower pace. More and more projectiles pass and reach the ennemy ships. In less than a minute all of them have silently exploded as the swarm passed.

The war is over, in one salvo.

Ok first thing. Even billions of railgun rounds will be very spread out in space. Ships could detect their trajectories and move to pass between shots. They could also return fire using lasers at a much greater range than railguns would be effective and damage the sensors. Once a ship is blind its effectively out of combat.

Also ammo. You will not have billions, or millions, or thousands, or even hundreds of shots for a large railgun. Modern warships carry relatively limited ammo and they aren't constrained by weight in the same way. If you say a ship has a billion shots, each shot weighing say 5kg, it comes out as weighing 5million tons. That 78 Yamato battleships. And that's just the ammo.

A real military ship would be a satellite, with propulsion and a missile rack, maybe a laser if we're talking 20 years in the future. Its likely to weigh 20 tons max, more likely closer to 10.

[baggers]

Ok first thing. Even billions of railgun rounds will be very spread out in space. Ships could detect their trajectories and move to pass between shots. They could also return fire using lasers at a much greater range than railguns would be effective and damage the sensors. Once a ship is blind its effectively out of combat.

Also ammo. You will not have billions, or millions, or thousands, or even hundreds of shots for a large railgun. Modern warships carry relatively limited ammo and they aren't constrained by weight in the same way. If you say a ship has a billion shots, each shot weighing say 5kg, it comes out as weighing 5million tons. That 78 Yamato battleships. And that's just the ammo.

A real military ship would be a satellite, with propulsion and a missile rack, maybe a laser if we're talking 20 years in the future. Its likely to weigh 20 tons max, more likely closer to 10.

Hey, I assume you can shot all theses from a... regular battleship on the sea ^^ You don't have to send the railgun and ammo to space at first.

Or just have a bunch of land railguns connected to the ammo factories, for that matter. (but regular battleships with railguns are way more cool and can easily be refited with ammo all along the day)

Edited September 17, 2015 by baggers

[cicatrix]

Hey, I assume you can shot all theses from a... regular battleship on the sea ^^ You don't have to send the railgun and ammo to space at first.

Or just have a bunch of land railguns connected to the ammo factories, for that matter.

Hardly, you will also need a nuclear power plant to fire those in space and the railgun itself will be so huge that it would be hardly possible to make it mobile. Aiming that thing would also be kind of difficult.

[baggers]

Hardly, you will also need a nuclear power plant to fire those in space and the railgun itself will be so huge that it would be hardly possible to make it mobile. Aiming that thing would also be kind of difficult.

Actual small railguns are able to suborbital shots. And are carried/powered by small ships like "spearhead" class high speed catamaran.

I assume a nuclear powered specialised battleship will easily handle interplanetary range railguns.

(Just for pleasure, if you haven't already see it: http://forum.kerbalspaceprogram.com/threads/134317-Big-guns-in-space )

Edited September 17, 2015 by baggers

[shynung]

Half of those assume you couldn't get a bigger destructive potential with an inert warhead. Since you can, there is little point to build such expensive things. I mean, "chemical payloads to corrode metal"... Seriously?! You are just throwing technobabble there. At interplanetary engagement speeds (or railgun speeds, for that matter), you pack more damage in kinetic energy than what high explosives can give you.

Chlorine trifluoride (ClF3) chews through almost anything. I'm pretty sure there are other nastier stuff that one can make in labs, but I'll leave it there.

But again, IT'S NOT LIKE MISSILES WILL BE EVER ABLE TO HIT A LASER WARSHIP. For the nth time, a laser can blind anything long before it has any chances of shooting at it with anything, except another laser. Meaning railgun rounds won't find the target to fire at, and missiles won't know where to be guided to. And if they did, somehow, through magic, they could be blown out of the sky by the same laser when they get a bit closer.

Except the missile is a laser-carrying miniature unmanned spaceship. It doesn't have to be right next to the ship it's looking for, just close enough that light-speed lag is low enough so that quick targeting is possible. Despite the power requirements of laser weapons, it doesn't need radiators as big a larger ship would, because all it has to do is to pump out one good zap with its laser, and that's it; destruction of the reactor core or laser emitter/turret immediately afterwards is acceptable. It also doesn't need propellant to get back to where it came from, so it doesn't suffer too much from the rocket equation.

Also, its sensors don't have to track the target all the time. It can instead receive targeting information from the ship that launched it, or even outright controlled from the launching ship. The sensors and emitters can be buried inside ablative armors able to shrug off whatever sensor-blinder laser the target may have, and pop open via explosive bolts at the moment just before firing. Like that, the vulnerable moments are the time frames between armor popping off and laser firing, and this can be reduced to milliseconds or even microseconds with the right equipment and the right firing sequence.

Heck, mount several targeting sensors on separate disposable ablative armor fairing, and pop them open before the main laser fairing. Get enough targeting data with these sensors before the target's anti-sensor lasers blind them, then aim the main laser using this targeting data, while still covered by ablative fairing. This way, when the main laser's fairing popped off, it's already aimed at the target, reducing time from pop-off to laser fire even smaller.

Like this, the only way a target can defend itself is to destroy the missile outright, using lasers meant for engaging other ships. If the target has only a few anti-ship lasers, a laser-missile swarm would ensure a few got close enough to unload a few zaps.

Edited September 17, 2015 by shynung

[Rune]

Rune, isn't that you who are speaking about the "Arrow Vs Armor" just before?

That "armor of lasers" will just fall like all of theses at the long run, I bet ^^

- - - Updated - - -

And if you're on the "big war" thing:

Imagine a planet. War comes.

The ships sail. They have railguns, some, big. And ammo. Many ammo.

They shot. One projectile after the other. At a slow pace. Kepping their barrels colds. They fire the entire day. And the entire week. And the entire month. One month after the other. Dozen, hunderds, thousands, millions and billions of railgun guided projectiles.

The projectiles are on their way. They have month, maybe year before reaching the target. From a straigh long line, they slowly adjust pace, regroup. Ultimately form a gigantic swarm.

That swarm of billions and billions of projectiles came at once on the ennemy territories. Like small baby turtles just born on the coast and reaching the oceans full of dangers. The ennemy lasers are everywhere, the ennemy probes take down hunderds, thousands, millions of thems.

But they reach the target: the ennemy fleet, and still are billions.

The ennemy fleet lasers fires, warm, hot, all at once.

But they can do nothing about theses billions, coming in one inarretable swarm. One projectile pass. One ennemy ship is disabled. The fleets lasers start to overheat, some laser start to fire at a slower pace. More and more projectiles pass and reach the ennemy ships. In less than a minute all of them have silently exploded as the swarm passed.

The war is over, in one salvo.

You are talking about MAD. The only thing such an attack would be effective against, are stationary targets, and the enemy will probably respond in kind. After the initial exchange of volleys, with most of the civilian population dead on both sides, the remaining mobile assets would slug it out with lasers to see who gets dominion over the ashes.

Sure. Use an insulated sabot to do the acceleration, then decelerate the hot sabot so it dpesnt reveal the torps vector. Put directional radiators on the recon torps- what the enemy sensor platforms 5 light minues away report is irrelevant if the torp can change vector even slightly with cold gas thrusters. Passive sensors and a maser comunicator, to avoid betraying emissions toward the source of the mothership's laser blindness.

So you want to build a supercomplicated stealth guided missile, then hurl it out at 20,000 Gs out of a railgun at awful propulsive efficiency. Yeah, that makes sense. Especially when a solid booster would a better job.

Chlorine trifluoride (ClF3) chews through almost anything. I'm pretty sure there are other nastier stuff that one can make in labs, but I'll leave it there.

Except the missile is a laser-carrying miniature unmanned spaceship. It doesn't have to be right next to the ship it's looking for, just close enough that light-speed lag is low enough so that quick targeting is possible. Despite the power requirements of laser weapons, it doesn't need radiators as big a larger ship would, because all it has to do is to pump out one good zap with its laser, and that's it; destruction of the reactor core or laser emitter/turret immediately afterwards is acceptable. It also doesn't need propellant to get back to where it came from, so it doesn't suffer too much from the rocket equation.

Also, its sensors don't have to track the target all the time. It can instead receive targeting information from the ship that launched it, or even outright controlled from the launching ship. The sensors and emitters can be buried inside ablative armors able to shrug off whatever sensor-blinder laser the target may have, and pop open via explosive bolts at the moment just before firing. Like that, the vulnerable moments are the time frames between armor popping off and laser firing, and this can be reduced to milliseconds or even microseconds with the right equipment and the right firing sequence.

Heck, mount several targeting sensors on separate disposable ablative armor fairing, and pop them open before the main laser fairing. Get enough targeting data with these sensors before the target's anti-sensor lasers blind them, then aim the main laser using this targeting data, while still covered by ablative fairing. This way, when the main laser's fairing popped off, it's already aimed at the target, reducing time from pop-off to laser fire even smaller.

Like this, the only way a target can defend itself is to destroy the missile outright, using lasers meant for engaging other ships. If the target has only a few anti-ship lasers, a laser-missile swarm would ensure a few got close enough to unload a few zaps.

That is a really good case for laser drones, not an argument against laser weaponry. But note that I did never consider the size of a laser-equipped warship. In fact, in my example, it's just big enough to house a single weapon-grade laser. I do take the trouble of making it more than a one-shot disposable, but that is because otherwise, it has to be cheaper than a guided missile, else your one-shot drones can be overwhelmed with targets.

One comment, though: with lasers, your primary sensor ports will be the laser turrets themselves, they are by definition awesome optical telescopes. They can be armored with ablative shutters quite easily, but only if you aren't using it as a sensor (or a weapon) when it's closed.

Edit: Concerning nomenclature, now that I think about, and the comment from scoundrel about "laser stars of death"... a flock of laser drones would be a constellation, right? A constellation of laser-stars. The name works perfectly!

Rune. I knew I was going to spark some debate, I'm glad it's not everybody against me!

Edited September 17, 2015 by Rune

[baggers]

You are talking about MAD. The only thing such an attack would be effective against, are stationary targets, and the enemy will probably respond in kind. After the initial exchange of volleys, with most of the civilian population dead on both sides, the remaining mobile assets would slug it out with lasers to see who gets dominion over the ashes.

I must say I find pleasant the little "picture" I paint in that post. A guilty immagination pleasure, naturally!

But at a smaller scale, don't you think a swarm of enough projectiles could outclass any laser defence?

[Scoundrel]

I woudl say +1... almost. That "cutting things in half" comment.

A continuous rod warhead (or annular blast fragmentation warhead if you prefer) is a warhead that uses explosives to create a ring of metal (typically tungsten) that does far more damage close in than a standard fragmentation warhead. It does this:

They are currently used on high-end A2A missiles: if an aircraft falls within range of the ring and it is oriented properly, it can (and has!) cut the fuselage of drones and aircraft in half! Oriented just 45° off and it'll rip off wings and control surfaces and usually an engine. It's only disadvantage, aside from its expense, is that beyond R, it is significantly less effective than fragmentation warheads, so it is used almost exclusively for anti-aircraft and anti-missile purposes - though I believe there are some anti-shipping weapons that also use it, but I wouldn't swear to it. Considering the type of armour that we would encounter in vacuum, it would be reasonable to assume that we'd see these style of warheads as the preferred type.

Area-denial weapons like those debris-seeding ideas come into a few problems, too: a) space is big, detection is dumb easy, and c) you only need miligees to sidestep them, considering your reaction time.

It would seem so... however, with respect, I would counter with:

a) the vastness of space is irrelevant since we're talking about putting objects in the orbital path of another vessel around a planet/moon. If we were talking a vessel moving in between celestial objects, then yes, I completely agree with you: area denial weapons would be stupid. However, since we're talking about objects in orbit, we have to acknowledge that, since detecting objects in space is easy, in the future, fire control computers will likely eventually have the ability to calculate a target's orbital path. And that ability will give us options.

detection is based on situational awareness, which is not always the case if we're talking about combat. Our target vessel could be blinded, or its commander and its TAO have tunnel vision... but again, it's not relevant. Tactically speaking, the point of area denial in space is to force the enemy to burn fuel to move because it will run out of fuel at some point if its forced to continually increase its orbit or change it; or to increase the amount of time it is exposed to enemy fire, or reduce the window it has to return fire, etc. How effective that would be in reality, I couldn't say, because we'd end up debating the cloud size, the dV of the defending vessels, trying to figure out their orbits, etc. I'm simply talking conceptually.

c) if we assume that a vessel detects a debris cloud moving in the same direction, then yes, I would submit that changing its path with a short RCS burst would be trivial. If, on the other hand, the debris cloud is moving in the opposite direction, then it would be detected at a less than optimal point that would require a greater expenditure of fuel, especially since it would be the fear of outliers around that cloud that would drive a captain to give it a wider berth, just to be safe. Again, not a lot of fuel to dodge (though more than burning at apo/peri)... but if you force the enemy vessel to drunkwalk to counter future area denial attacks, then it will eventually significantly reduce the dV of the enemy vessel and limit its tactical options.

That said, that whole thing is simply a what-if example of the possible use of area denial weaponry, and I've deliberately avoided the whole Kessler Syndrome issue because that is just as likely a reason not to use those types of weapons as is the favoured laser only doctrine. After all it's basically mine-laying but using a canister to spew something the size of shotgun pellets and exploit the fantastic relative velocities rather than an explosive contact device, to force the enemy to react. I imagine it would be rare for a vessel to actually hit them... satellites, though, might make the perfect victims.

But yeah, lasers or KE weapons aside, MAD sure seems like the outcome of any real space battle.

One comment, though: with lasers, your primary sensor ports will be the laser turrets themselves, they are by definition awesome optical telescopes. They

can be armored with ablative shutters quite easily, but only if you aren't using it as a sensor (or a weapon) when it's closed.

You would use camera shutter controls with heat sensors and they would flicker at about 1/1000th of a second in "combat mode." Scatter them about the hull and you can make it very difficult to blind.

Gah, sorry for the double quote... I don't get why they glitch like that.

Edited September 17, 2015 by Scoundrel

[Rune]

I must say I find pleasant the little "picture" I paint in that post. A guilty immagination pleasure, naturally!

But at a smaller scale, don't you think a swarm of enough projectiles could outclass any laser defence?

For a static defensive position, sure, anything can theoretically be overwhelmed. A mobile platform, OTOH, would see them coming (if only as part of its MMOD avoidance routines), and side-step them without wasting a single watt of offensive power.

[stuff I really can't find a fault with]

Well... yeah, basically. You are right. Railguns would have optional warhead modes to tailor their energy discharge (basically, their radius/consistency at the point of impact). Solid penetrators, or "fragmentation" warheads for soft targets, or multiple warheads in a row against whipple shields. If they were relevant in ship-to-ship combat, specific warheads for that would be made. As siege weapons, probably the main factor is the cost of each shot, though.

And yeah, orbital combat can be messy, especially in a setting with a complicated war with many actors sharing close orbital space. Hostage situations, civilian infrastructure, third neutral parties, maybe even a watchful higher authority enforcing some "house rules" (Space Guard so nobody employs killer asteroids or nukes on civilians?)... the possibilities are endless, so hard sci-fi isn't dead by any means. But, we are talking warship design here, so this is why I assume total war conditions, that's what a warship will be designed for, primarily.

Edit: this one I can comment

You would use camera shutter controls with heat sensors and they would flicker at about 1/1000th of a second in "combat mode." Scatter them about the hull and you can make it very difficult to blind.

Gah, sorry for the double quote... I don't get why they glitch like that.

First, don't worry, I edit my own posts obsessively to try and catch errors. I have fat fingers. And second... 1/1000th of a second is actually how long your standard laser pulse lasts. "Now if we can find their frequency to bypass their shields..." who am I kidding, these things will be fought by computers over sensor advantage long before "flashy explosion" range.

Rune. See? I can agree, too! Sometimes... XD

Edited September 17, 2015 by Rune

[shynung]

That is a really good case for laser drones, not an argument against laser weaponry. But note that I did never consider the size of a laser-equipped warship. In fact, in my example, it's just big enough to house a single weapon-grade laser. I do take the trouble of making it more than a one-shot disposable, but that is because otherwise, it has to be cheaper than a guided missile, else your one-shot drones can be overwhelmed with targets.

A drone, as in UAV (or, more aptly, USV), is expected to fly back to be refueled and rearmed. This thing doesn't fly back after it delivered the zap; in fact, the reactor core powering it would probably explode mere seconds after it has fired, due to the lack of radiators in an effort to shave off weight, a consequence of its single-shot concept.

This isn't a laser drone, it's a laser missile. To be precise, a guided missile carrying a weapons-grade laser as its offensive payload instead of explosives or kinetic energy.

One comment, though: with lasers, your primary sensor ports will be the laser turrets themselves. It can be armored with ablative shutters quite easily, but only if you aren't using it as a sensor when it's closed, or firing.

I think it's much better for the sensor ports to be inside separate optical turrets, much smaller than the main laser turret, and covered in separate ablative fairings. This way, it can traverse faster than the main turret, an obvious advantage when acquiring a target within a very limited time frame. It also means that the missile can carry several targeting turrets rather than relying on the main laser turret, which means the anti-sensor laser now has several eyes to blind, increasing the chances of the sensors acquiring a target before it gets blinded.

Note that I used fairings, not shutters. An ablative fairing similar to aerodynamic fairings used in orbital booster rockets can be simpler to build and open than a shutter system. Coupled with the fact that the laser turret won't survive firing the laser (due to having no radiators, resulting in it, along with its power source, overheating to Hell), the ablative covering doesn't need to be closed again, rendering the point of shutters moot.

I can even imagine a nastier version. Replace the directional optical sensor turrets with a passive omnidirectional sensor. When its fairing pops open, it lets itself get fired upon by anti-sensor lasers, thereby acquiring the position of the anti-sensor laser turrets. Train the main laser turret to this location, and pop the ablative fairing microseconds before firing. The target ship would have lost one of its laser turrets (possibly along with a few other things), opening the way to more devastating weapons that are more reliant on sensors.

Edited September 17, 2015 by shynung

[cicatrix]

Actual small railguns are able to suborbital shots. And are carried/powered by small ships like "spearhead" class high speed catamaran.

I assume a nuclear powered specialised battleship will easily handle interplanetary range railguns.

(Just for pleasure, if you haven't already see it: http://forum.kerbalspaceprogram.com/threads/134317-Big-guns-in-space )

Perhaps, but suborbital means zero speed at apoapsis = no destructive potential. You need moar energy.

And there's aiming too - 1 angular second deviation means you will miss by 174 meters at h=100 km. Ideally. Because there's wind too.