Physically plausible explanation for missile based space combat?

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I think that burst behind celestial part could work in orbital combat. To build up enough speed to intercept fusion ship on route, a huge way is required to boost.
If the missile is coming directly for ship, that makes hit not so hard, but to focus on a small area, that requires exact distance too.
The laser beam cant detected directly in space if your sensors arent hit by it, although the lascannon will still produce quite a heat sign.
However, from 100.000km with parameters i calculated, it takes quite a time to drill through armor.
 

Ryan_m_b

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A beamed weapon doesn't have to instantly kill, it just has to be shone on the target enough to heat damage the reflective armour and destroy it once this is done. Space is big and it takes a long time to physically move through it, even at 10Gs constant thrust it takes 41 minute to cross a light second. Within that range you can pretty easily aim a laser and be sure of it hitting. Even if it takes a solid ten minutes of shining a laser (with corrections as the missile moves and attempts to dodge) you're safe. Plus sustaining high acceleration for a long time is going to take a lot of fuel and a powerful engine. At that point your missiles become small nuclear spaceships.

It's worth noting as well that there are other forms of beam weapon that couldn't be so easily reflected, for example: particle beams, FELs and X-Ray lasers. In regards to the idea of swarming missiles sure: if you can deploy in such numerical strength then you'll win. But working with the assumptions I mentioned in the previous paragraph an attacker would need to launch 5 missiles at the defender to be sure of a win, and that's if they have only one point defence laser. If they have 10 you need to launch 41.

Edit: It would probably be useful to try and design a missile using technology appropriate for your setting. Work out the ISP and mass flow so you can figure out how much fuel its going to need to accelerate constantly and how much energy that will take. I may have a go later if I have more time than I do this evening, off the top of my head though I'd put money on any "missile" capable of doing this as becoming very large. At that point why not mount a beam weapon to it and make it a drone?
 
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A beamed weapon doesn't have to instantly kill, it just has to be shone on the target enough to heat damage the reflective armour and destroy it once this is done. Space is big and it takes a long time to physically move through it, even at 10Gs constant thrust it takes 41 minute to cross a light second. Within that range you can pretty easily aim a laser and be sure of it hitting. Even if it takes a solid ten minutes of shining a laser (with corrections as the missile moves and attempts to dodge) you're safe. Plus sustaining high acceleration for a long time is going to take a lot of fuel and a powerful engine. At that point your missiles become small nuclear spaceships.

It's worth noting as well that there are other forms of beam weapon that couldn't be so easily reflected, particle beams for instance. In regards to the idea of swarming missiles sure: if you can deploy in such numerical strength then you'll win. But working with the assumptions I mentioned in the previous paragraph an attacker would need to launch 5 missiles at the defender to be sure of a win, and that's if they have only one point defence laser. If they have 10 you need to launch 41.
As far as i know, particle beams scatter more than lasers (at this point i plan to introduce plasma point range defence as a breakthrough in the later half of story, but will be countered by magnetic field warheads that scatter the beam)
With the 30km/s closing speed i assumed, it is near three hours... More than a ton of titan with my previous calculations...

Hmm, although attack warship can have a ton of armor, it only have to mask the heat and light signs of attack missiles/drones by provide enough background clutter.
 

Ryan_m_b

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Particle beams can be neutral, magnets won't affect them and they won't be repulsive so scatter won't be much of an issue (certainly not in vacuum). The U.S. Navy has a project for FEL point defence on their ships IRL. So if you're willing to speculate that there's no show stoppers were not aware of it would seem they are plausible as a long range space weapon.

As for hiding the ships I'm not convinced. You'd have to put out a fantastic amount of energy in order to "over expose" all their sensors. Bear in mind we have technology that allows cameras to filter out the light of the sun, unless you have more than that focused on the enemy ship they're going to see you.

30kmps is very slow. It would be within the effective range of a beam weapon for quite a lot of time.
 
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Particle beams can be neutral, magnets won't affect them and they won't be repulsive so scatter won't be much of an issue (certainly not in vacuum). The U.S. Navy has a project for FEL point defence on their ships IRL. So if you're willing to speculate that there's no show stoppers were not aware of it would seem they are plausible as a long range space weapon.

As for hiding the ships I'm not convinced. You'd have to put out a fantastic amount of energy in order to "over expose" all their sensors. Bear in mind we have technology that allows cameras to filter out the light of the sun, unless you have more than that focused on the enemy ship they're going to see you.

30kmps is very slow. It would be within the effective range of a beam weapon for quite a lot of time.
Neutral particle beams? I thought they need to be charged in order to accelerate them, two opposite charged beams can be used, but it will be still a plasma weapon. Is there some new development?

I thought at first 100 km/s but i would need at least a GW reactor, then explain why lasers could only produce a MJ / sec?

That fantastic amount of energy wouldnt be still much less than do serious damage to armor? Well, that sun filter camera is surely interesting, any link about it, how much decibel of light intensity it can handle?

Well i found that Sun is magnitude -27 6.31×10^10 compared to magnitude 0.
With 10.000km and some kW-s of light and thermal radiation, that scatter everywhere (10^14 distance squared), and few kWs laser hits all the ship it would be 10^14 more laser power than signal power.
 

Ryan_m_b

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Read the link I posted above about modern research in particle beams. I don't understand the technology exactly but it seems like it's possible now to create a beam emitter that charges the atoms, accelerates them, then adds/subtracts an electron just as they leave creating a very fast stream of neutral particles.

As for a sun filter if you google it I'm sure you'll find plenty of examples. Its a pretty common piece of kit for photographers wanting to take pictures of solar eclipses and the like. God knows what the best possible filter could do in the world, or what could be developed by a military if needed.

Jamming sensors suffered from the same problem as beam weapons: the further away you are the more powerful a laser you need to guarantee a hit (by spreading the beam over a wider area). That quickly becomes impractical. If you're close enough that you can flood their sensors and keep doing so as they dodge and roll you're close enough to hit them with something more powerful, and be hit by the same.
 
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Read the link I posted above about modern research in particle beams. I don't understand the technology exactly but it seems like it's possible now to create a beam emitter that charges the atoms, accelerates them, then adds/subtracts an electron just as they leave creating a very fast stream of neutral particles.

As for a sun filter if you google it I'm sure you'll find plenty of examples. Its a pretty common piece of kit for photographers wanting to take pictures of solar eclipses and the like. God knows what the best possible filter could do in the world, or what could be developed by a military if needed.

Jamming sensors suffered from the same problem as beam weapons: the further away you are the more powerful a laser you need to guarantee a hit (by spreading the beam over a wider area). That quickly becomes impractical. If you're close enough that you can flood their sensors and keep doing so as they dodge and roll you're close enough to hit them with something more powerful, and be hit by the same.
ok, i see you edited last post, i read it.
Otherwise the good thing about particle beams, that the fusion ships rocket is also kind of particle accelerator, so technology might be bit similar...
Still, without big focusing mirrors i can hardly imagine them to be focused as much as lasers. According to link, that applies to present day xaser as well.

http://www.mreclipse.com/SEphoto/SEphoto.html
These filters typically attenuate the Sun’s visible and infrared energy by a factor of 100,000.
 
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Ryan_m_b

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I'd be inclined to think that isn't an insurmountable problem. Particle accelerators crash streams of particles together at a whisker under the speed of light and the military seems to think that hitting an object miles away shouldn't be much of a problem. If you're setting has nuclear fusion propulsion space craft it doesn't seem unlikely that a technique for focusing particle beams over a light second would be in use.
 
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It's worth noting as well that there are other forms of beam weapon that couldn't be so easily reflected, for example: particle beams, FELs and X-Ray lasers. In regards to the idea of swarming missiles sure: if you can deploy in such numerical strength then you'll win. But working with the assumptions I mentioned in the previous paragraph an attacker would need to launch 5 missiles at the defender to be sure of a win, and that's if they have only one point defence laser. If they have 10 you need to launch 41.
Considering we already have MIRV missiles that separate into 14 independently targeted re-entry vehicles each, is that really an obstacle? Just launch 10 of those and you've got a 140-missile Itano circus.

A beamed weapon doesn't have to instantly kill, it just has to be shone on the target enough to heat damage the reflective armour and destroy it once this is done. Space is big and it takes a long time to physically move through it, even at 10Gs constant thrust it takes 41 minute to cross a light second. Within that range you can pretty easily aim a laser and be sure of it hitting. Even if it takes a solid ten minutes of shining a laser (with corrections as the missile moves and attempts to dodge) you're safe. Plus sustaining high acceleration for a long time is going to take a lot of fuel and a powerful engine. At that point your missiles become small nuclear spaceships.
How do you know you can even detect them? They could (reasonably enough with near-future tech) be practically invisible to radar and visible light and if their orbit is aligned to intersect with yours, they don't even need to burn their engines.
 
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Ryan_m_b

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Again it depends on your missile. If you can carry enough to overwhelm an enemy then fine, but if you're of equal resources then you don't have that option. In terms of being detected anything hotter than the background of space can be detected with IR sensors, the hotter the easier. With an interferometer array you could be continually scanning your system and identity all objects of this sort. After its launched it doesn't matter if it goes cold and relies on radar/invisible stealth because it would be child's play for a computer to extrapolate current position based in previous speed and heading.

Even pointing your exhaust away doesn't help. The heat from the reaction (especially if you require a powerplant for the engine) will be enough to make your ship hundreds of degrees hotter than the background.
 
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An Ohio-class submarine has 24 ICBM tubes, each of which can launch a Trident missile that splits into 12 separate, independently targeted missiles, for a total of 288 missiles in one barrage. If it were launching old Peacekeeper missiles from the 1960s, there would be 336 missiles per barrage. Just seems like a point-defense laser might have some trouble coping is all.

And those are ICBMs. If we were just talking about tactical nuclear warheads, it could be an entire new definition of spam.

Yeah, it's expensive, all those missiles, but victory is the only thing that counts. If you don't win, your entire spacecraft is a waste of money.

And if you launch from the other side of the planetoid (I'm guessing most space combat happens in orbit), the enemy wouldn't have any chance of detecting their engine heat. After the initial burn, they could just coast the rest of the way to intercept.
 
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In case of convoy attack, fight happens in deep space. Otherwise, most likely they fight around an asteroid.
 

Ryan_m_b

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Gain it depends on how good your point defence is. If you can deliver multi-mega joule particle beam shots then it's a question how how rapid is your rate of fire (for orbital distances the chance of missing is likely to be nil). As a quick exercise:

Let's say missiles and target have a closing speed of 50kmps and they're detected 1000km out. That's 20 seconds before being hit. If there are 500 missiles incoming then the rate of fire to guarantee safety is 25 shots per second. Now it comes down to how many beam emitters you have and how rapidly they can fire. If you have many...it starts seeming reasonable within the confines of the setting.

As for where battles occur I don't see why it would be primarily in orbit. If you're attacking a planet then you have to travel from somewhere else. Given that's the case battle would likely start once the chances of hitting someone with a long range weapon within a reasonable time converge. I expect the shooting would start at distances of light seconds, if you had beam technology good enough. Even if not the attacker in this scenario would be better off firing a whole bunch of beam drones ahead of them to engage the enemy.

In an effort to jump ahead (we seem to be circling a bit) I'd like to pose this question: why would a barrage of missiles be better than a barrage of beam-drones? The latter seem the obvious choice to me (assuming equivalently effective tech) because as the two barrages close the drones begin to fire, picking off the missiles. For a missile to kill a drone it has to be very close, likely much closer than the effective range of a beam weapon.
 
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My problem with beam drones, that they dont have the power source and waste heat treatment of the ship.
(Although the ship could give them power with lasers.)
If one attacks an asteroid, he will come with superior firepower, cover in this situation could help the defenders.
I rather care about total power output than number of lasers.
In case of particle waepons also appropriate, i wonder, what if the defender had a really strong magnetic field, to bring back the metallic particles and reattach it to the hull?
 

Ryan_m_b

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Likely a drone would have to be fairly large to carry a power source and radiators. Still even if they were 10 tonnes a squadron of 10 would mass just 20% of the ISS. The advantage to beam drones is that they could fire at distance whilst approaching the enemy allowing you to keep your craft further away. Missiles might be good if you fire enough at close distance but if you have to fire from long range they'll be picked off.

I don't know what you mean by a magnetic field to draw in metal. If the attacked was shooting metal at you then maybe (but it would have to be insanely powerful to deflect anything) but that won't help against a neutral beam of non metal particles.

In your setting I presume the asteroids are habitats? If so a beamed weapon would be quite appropriate. You could fit quite a large reactor and radiators on an asteroid. Having a continual gigawatt weapon would seem possible in that situation.
 
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I'd like to pose this question: why would a barrage of missiles be better than a barrage of beam-drones? The latter seem the obvious choice to me (assuming equivalently effective tech) because as the two barrages close the drones begin to fire, picking off the missiles. For a missile to kill a drone it has to be very close, likely much closer than the effective range of a beam weapon.
Beam drones seem a bit more high-tech. They need more power, more accurate targeting, more efficient propulsion/fuel (missiles aren't supposed to return when their assignment is completed), etc.

Against a larger spacecraft, they could partly make up for the lower energy of their individual beams by focus-firing, though.

And your prediction rests on the assumption that the missiles' stealth and ECM is ineffective.
 
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I thought about use the magnetic field to reattach the metallic particles torn from the armor by the beam. Or make them super hard to evaporate.
(So a kind of energy shield...)

Yes it is a problem, that planetary defence has quite an amount of resources, it is hard to overwhelm.

I also give a fairly low chance to that stealth thing, if they really try to discover them with both active and sensitive IR sensors (and they can really detect very small intensity of IR radiation), i focus on other solutions.

I think on the equip the fighters with lasers thing, after all, they dont need all the power output of ship, just produce a big pulse to produce a beam capable to damage sensors, focusing equipment etc.
 

Ryan_m_b

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Stealth just doesn't work in space, for reasons discussed (you can find long essays/articles on this online that go over this issue). Drones would require more mass and technology, they'd essentially have to be small unmanned nuclear space craft. But even if you carry less of them it's a question of how much more effective they are. IIRC project NERVA consisted of a small nuclear reactor capable of in excess of a hundred megawatts of power. If you take just 10% you have a potential ten megawatt beamed weapon.
 

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I'm just not convinced of the "no stealth in space" claims. It seems not to account for likely developments in technology. Plasma stealth and infrared invisibility are both current areas of active research and new systems are being worked on all the time.
 
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I'm just not convinced of the "no stealth in space" claims. It seems not to account for likely developments in technology. Plasma stealth and infrared invisibility are both current areas of active research and new systems are being worked on all the time.
If thrusters operate it would require Mass Effect magitech to make it IR invisible. Also there is a finite limit of containing waste heat, plus heat comes from swallowing beams of active sensors.
Maybe in orbital combat, but i would exclude it in deep space.
 
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Thrusters don't necessarily have to operate at all after the initial launch. It depends what you're trying to do.

And besides, stealth can take other forms besides just rendering something undetectable. Stealth also encompasses decoys, sensor ghosts, ECM, etc.
 
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Thrusters don't necessarily have to operate at all after the initial launch. It depends what you're trying to do.

And besides, stealth can take other forms besides just rendering something undetectable. Stealth also encompasses decoys, sensor ghosts, ECM, etc.
ECM, well that is my original idea of jamming is easier than burn through armor with beam weapons, no matter how sensors are hardened. but focus X-ray this punctual...
Maybe i should really forget the epic space battle thing in this setting, and save it for FTL setting...
Laser drone fighters still rather unepic, no dodging shrapnels, no missiles closing in etc...
 

Ryan_m_b

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I've read books that take the drone approach that do have some pretty epic space battles. The nights dawn trilogy I'd highly recommend if you're interested in that (a fantastic trilogy overall as well). It is an FTL setting so the battles do tend to be closer. The tension comes from when enemy drones burst through your own (through luck or greater numbers) so now they're careering towards the ship intent on destroying it.
 
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Also, the earlier estimates for missile barrage (336 independent missiles, etc.) are based on Trident missiles, the MIRVs of which are all 100-kiloton warheads (Hiroshima was 16 kilotons). If you're firing smaller, 1-kiloton tactical nuclear weapons, you wouldn't be talking about hundreds of missiles, but several thousands per barrage. I think even a network of advanced beam drones could have difficulty stopping that.
 

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