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Best Point Defense Versus Space Battles.... Scifi and Real Life


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A common scifi scenario will have long range missiles in space trying to intercept manned spaceships.

Missiles that can chase a ship for hours at high rates of thrust (15g for example).

In such a case, if a swarm of missiles is coming at a manned spaceship, what are the best point defense systems you can think of to disable or destroy the missiles before they catch up to the manned ship?

Assume there is no way the manned ship can outrun the missiles and they will hit in about 2 hours unless the ship can destroy or disable them.

 

Approximately 40 missiles are incoming!

 

IRL: Actually makes it a lot easier paradoxically because missiles do not have ridiculous range or constant high acceleration.

 

Point defense options:

 

Lasers: Unless your vessel is already a dedicated laser star it won't have great long range lasers that can do a lot of damage at long range. If it is one of those average jack of all trade scifi ships and NOT  a dedicated all or nothing giant laser lens warship it can forget taking on the missiles with small lens lasers. To get good range you need a large lens... leading to a spaceship that looks like a giant camera lol that needs to point the entire ship at what it wants to fire.... or do some fancy stuff interior chamber with mirrors to give a limited firing arc range from forward mounted laser... or put it on a giant gimbal. Ugly but effective. Congrats! The face of the ship is a giant laser turret.

Railguns: Short range but lots of damage. The real problem is hitting stuff with it... especially if it is a nimble long range 15g missile and you have to destroy 40 of them!

 

Plasma:  Can be fired at high speeds but damage is light unless the target is at relatively close range... which is bad if ut us a swarm of missiles.

 

Nuke missiles: Might actually work. Just send a bunch toward the missiles and detonate. Hopefullyl the radiation abd shrapnel screws up the missile guidance systems.

 

So the irony is that the best way to take out a 15g long range missile is with another missile... loaded with a nuke snd tungsten shrapnel perhaps?

 

Edited by Spacescifi
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David Weber's Honor Harrington books have extended sequences of missile vs point defense in his space combats. In it, the outer layer of defenses is basically proximity kill countermissiles, smaller and faster than a shipkiller. Point defense laser clusters provide close in defense, and the shields and armor of the ships mitigate but do not prevent  battle damage from skipkiller weapons armed with standoff bomb-pumped Xray laser warheads.

The one time "on screen" someone got a nuclear armed shipkiller through the teeth of a modern ship's point defenses, it destroyed everything on that side of the ship, but the ship itself was able to limp away.

 

Edit: the Expanse also relies heavilly on interdiction and point defense.

Edited by Rakaydos
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ToughSF by @MatterBeam has a good article thingy on the subject. 

14 hours ago, Spacescifi said:

Lasers: Unless your vessel is already a dedicated laser star it won't have great long range lasers that can do a lot of damage at long range. If it is one of those average jack of all trade scifi ships and NOT  a dedicated all or nothing giant laser lens warship it can forget taking on the missiles with small lens lasers. To get good range you need a large lens... leading to a spaceship that looks like a giant camera lol that needs to point the entire ship at what it wants to fire.... or do some fancy stuff interior chamber with mirrors to give a limited firing arc range from forward mounted laser... or put it on a giant gimbal. Ugly but effective. Congrats! The face of the ship is a giant laser turret.

You can use sand to kill lasers.

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@Spacescifi

Your best bet is to think like a weapons designer.  And then escalate and counter.  Escalate and counter.  Weapons (*includes the ships and missiles and countermeasures) evolve over time given new technology and threat assessments - and that's part of what makes them interesting.

Get a detailed look at WW1, WW2 and Modern Warships that show how they were armed and armored against various threats.  You will see 'torpedo bands' and certain areas heavily armored and certain parts virtually unarmored.  You will see compartmentalization increase and armor decrease and shift  - and all of that is due to the expectation of what threats the ship faces at time of design, along with what offensive weapons they carry.  WW1 boats don't have a lot of AA.  Postwar boats don't either; but they do have different systems.  Lots of guns becomes virtually no guns but plenty of missiles...

So create your first goodguy space battlecruiser, then design one for the enemy and give the enemy weapons to kill the first.  Then give the goodguys counterbattery and a new badguy killing weapon and have the badguys need to find a way to overcome that.  Allow a stalemate period, followed by a new tech that kills one side and have them counter.  Etc.  Force ship design changes based on each advance.  Maybe someone gets a new drive that limits the ability to use an old system.  Maybe someone develops better stealth - except the boat has to be slower.  Through this iterative process, you will be both building story and 'classes' of ships and an interesting 'world' that your characters inhabit and talk about.

7 minutes ago, Admiral Fluffy said:

You can use sand to kill lasers.

I forget where I got it from, but "Sparkle" is my favorite space-based countermeasure.  Like chaff - it's basically a mixture of metal flakes and crystals with a thermal component designed to puff cheap clouds of stuff between you and what's chasing you.  Drop a mine behind it and watch the fireworks.

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33 minutes ago, Admiral Fluffy said:

ToughSF by @MatterBeam has a good article thingy on the subject. 

You can use sand to kill lasers.

Sand doesnt accelerate, and so is useless for  counter-countermeasures for missiles. It can make missiles more prevailent in settings where theres little in the way of maneuver during battle and so can stay between you and the enemy for much of the battle, but not so much if you actually want to maneuver, and so leave the sand behind.

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1 minute ago, JoeSchmuckatelli said:

Right - but you pop the sand to 'go dark' and then turn or puff sand while you Brave Brave Sir Robyn as fast as you can.

So what's your plan for the missiles? The ones smart enough to go for your last known vector if you go dark?

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Oh, easy.  

After popping a can or two of Sparkle you drop a Whizzer.  The Whizzer gives the impression of the back of a ship in full flight and the missiles that get through the Sparkle cloud start looking and the only thing they can find is the Whizzer.  Classic Sub Warfare tactics.

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@Spacescifi If the missiles have 15g thrust for 2 hours, I think their final velocity is 3.8 BILLION meters/h, or greater than 10 times light speed. That assumes warp capable civilizations. Or maybe the missiles stop accelerating and can't quite reach light speed. Regardless, those sorts of speeds require fantastic technologies. Can you provide more background on what propulsion and sensor tech exists in your setting?

Where is the defensive ship located? If in orbit or relatively near to some large body, entering the atmosphere or landing on the far side from where the missiles are coming could be a good defense. The missiles will burn up on reentry. (or depending on which scifi version of FTL is being used, cause planet-wide destruction).

Do the missiles have deflector shields? If not, a cloud of sand or ice particles might be a great defense by shredding the missiles. The sand or ice doesn't have to accelerate and can rely on the missiles' velocity. If the missiles have good deflector shields, any kinetic defense might be useless.

Now, if the missiles do have deflector shields, then we can assume the ship also has deflector shields, and that might be the only defense needed against missiles.

What sensors does the ship have? That's especially important if the missiles are warp capable; the missiles will hit before the ship can detect them visually or with radar. Sand works as long as you know an attack is coming; there's no need to actually detect the missiles.

Once we know if/how the ship can detect the missiles, we can assume the missiles have similar tech, and we can discuss the viability of the ship jamming the missiles' sensors.

Even if the ship can't move as fast as the missiles, it might still be fast enough to charge at the missiles and exceed the missiles' sensor capabilities.

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39 minutes ago, DeadJohn said:

@Spacescifi If the missiles have 15g thrust for 2 hours, I think their final velocity is 3.8 BILLION meters/h, or greater than 10 times light speed. That assumes warp capable civilizations. Or maybe the missiles stop accelerating and can't quite reach light speed. Regardless, those sorts of speeds require fantastic technologies. Can you provide more background on what propulsion and sensor tech exists in your setting?

Where is the defensive ship located? If in orbit or relatively near to some large body, entering the atmosphere or landing on the far side from where the missiles are coming could be a good defense. The missiles will burn up on reentry. (or depending on which scifi version of FTL is being used, cause planet-wide destruction).

Do the missiles have deflector shields? If not, a cloud of sand or ice particles might be a great defense by shredding the missiles. The sand or ice doesn't have to accelerate and can rely on the missiles' velocity. If the missiles have good deflector shields, any kinetic defense might be useless.

Now, if the missiles do have deflector shields, then we can assume the ship also has deflector shields, and that might be the only defense needed against missiles.

What sensors does the ship have? That's especially important if the missiles are warp capable; the missiles will hit before the ship can detect them visually or with radar. Sand works as long as you know an attack is coming; there's no need to actually detect the missiles.

Once we know if/how the ship can detect the missiles, we can assume the missiles have similar tech, and we can discuss the viability of the ship jamming the missiles' sensors.

Even if the ship can't move as fast as the missiles, it might still be fast enough to charge at the missiles and exceed the missiles' sensor capabilities.

 

2 hours at 1g will not get you to ten times lightspeed. It would take about a year at 1g to hit lighthugger speed (but you would likely die from blueshift radiation before then).

 

The missiles are just as stated. Nothing more. They can be destroyed as easily as any other rocket or missile.

For this scenario the manned ship cannot warp away due to a lack of power.

 

And the attack occurs in deep interplanetary space, for example something like halfway to mars (or an analogue to that).

2 hours ago, JoeSchmuckatelli said:

@Spacescifi

Your best bet is to think like a weapons designer.  And then escalate and counter.  Escalate and counter.  Weapons (*includes the ships and missiles and countermeasures) evolve over time given new technology and threat assessments - and that's part of what makes them interesting.

Get a detailed look at WW1, WW2 and Modern Warships that show how they were armed and armored against various threats.  You will see 'torpedo bands' and certain areas heavily armored and certain parts virtually unarmored.  You will see compartmentalization increase and armor decrease and shift  - and all of that is due to the expectation of what threats the ship faces at time of design, along with what offensive weapons they carry.  WW1 boats don't have a lot of AA.  Postwar boats don't either; but they do have different systems.  Lots of guns becomes virtually no guns but plenty of missiles...

So create your first goodguy space battlecruiser, then design one for the enemy and give the enemy weapons to kill the first.  Then give the goodguys counterbattery and a new badguy killing weapon and have the badguys need to find a way to overcome that.  Allow a stalemate period, followed by a new tech that kills one side and have them counter.  Etc.  Force ship design changes based on each advance.  Maybe someone gets a new drive that limits the ability to use an old system.  Maybe someone develops better stealth - except the boat has to be slower.  Through this iterative process, you will be both building story and 'classes' of ships and an interesting 'world' that your characters inhabit and talk about.

I forget where I got it from, but "Sparkle" is my favorite space-based countermeasure.  Like chaff - it's basically a mixture of metal flakes and crystals with a thermal component designed to puff cheap clouds of stuff between you and what's chasing you.  Drop a mine behind it and watch the fireworks.

 

Nice.... but easily defeated.

 

Stick a camera on a missile nose and make it smart enought to release a cloud of sand IS NOT a spaceship.

With preprogrammed tactics built in to to avoid the sandclouds.

 

That leads the goid guys to go full star trek hologram decoy ship.

At which point the goodguys go bankruot and sue for peace from desiging sych expenaive defenses lol.

 

At some point offense just trumps defense no matter what you do.

 

A good offense is always better than a good defense.... since you do not need ti defend if your foe is non-existent.

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13 minutes ago, Spacescifi said:

With preprogrammed tactics built in to to avoid the sandclouds.

I wasn't meaning shoot the sand at the missles. I was meaning shooting at the enemy lazers, to stop them from firing.  

And what is the payload?

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The Expance's answer is that, while a missile can do all kind of crazy maneuvers, eventually, it has to get to your ship in order to hurt you, and when it settles down on the final attack run, you can just shoot the thing. Just make sure you break it into small enough parts that the wreckage isnt a kinetic kill vehical on it's own.

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10 minutes ago, Rakaydos said:

while a missile can do all kind of crazy maneuvers, eventually, it has to get to your ship in order to hurt you

And that's why the old Soviet projects are tougher than the Expanse battle ships.
A rocket doesn't need to get close.
It should just get enough close to make a direct shoot on fly-by.

If the rocket has a nuke-powered expendable Xray laser, the "close" can be a thousand of kilometers away.

And the ship is a much larger and easier target than the missile to aim.

Edited by kerbiloid
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11 minutes ago, Admiral Fluffy said:

Its much cheaper to shoot down a missle than it is to launch one.

This covers point defence, as does this.

If you can aim the tiny missile before it shoots first.

And the machine railguns like in Expanse would overheat in seconds, and start missing.
Also their ammo is limited, and their bullets are much slower than a Xray pulse from the missile.

1 000 km for 1 km/s bullet is 1 000 seconds.
While for the photons it's almost zero.

Also the missile can be easily masked from aiming by a cloud.

Edited by kerbiloid
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56 minutes ago, Spacescifi said:

2 hours at 1g will not get you to ten times lightspeed. It would take about a year at 1g to hit lighthugger speed (but you would likely die from blueshift radiation before then).

Your OP says "15g". Anyway, assumimg you meant 1g, then there's less magic required.

If the incoming missiles can target the ship from 2 hours away, the ship can use similar targeting to fire smaller, cheaper defensive missiles. If the incoming missiles have stealth, then the ship being targeted can use similar stealth to avoid being hit.

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4 minutes ago, DeadJohn said:

the ship can use similar targeting to fire smaller, cheaper defensive missiles.

If the countermissiles need to get close, the Xray missile will explode and hit the ship long before they can intercept it.

If the ship uses a lightspeed-fast beam weapon, the ship is much larger aim than a missile, so the missile has much greater chances to not miss.

If the missile releases a masking smoke cloud and strafes, the ship can't know, at which side of the cloud the missile will apear, while the missile always knows where the bulky ship is.
So, again the missile has better chances to hit first.

And if spend a ten of missiles per ship, it will be destroyed guaranteedly, together with all its anti-missile artillery.

Edited by kerbiloid
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1 hour ago, Spacescifi said:

Nice.... but easily defeated.

 

Stick a camera on a missile nose and make it smart enought to release a cloud of sand IS NOT a spaceship.

With preprogrammed tactics built in to to avoid the sandclouds.

 

That leads the goid guys to go full star trek hologram decoy ship.

At which point the goodguys go bankruot and sue for peace from desiging sych expenaive defenses lol.

 

At some point offense just trumps defense no matter what you do.

 

A good offense is always better than a good defense.... since you do not need ti defend if your foe is non-existent.

I'm not entirely sure what you are hoping to accomplish, then.

Observation: most adventure/space-battle sci fi is a variation on conventional warfare - simply writ to a different scenario.  This is accessible to people largely because of historical experience with the never ending battle between defensive and offensive technologies.  There is a constant tradeoff and cost to every advantage that can, with a little creativity be overcome or bypassed.  Makes military life interesting.

You seem trapped in a 'Tech can overcome everything' loop.  Not sure how you can get yourself out of that... but I will point out that every tech has limitations along with the capabilities.

 

FWIW - the "Sand Cloud" is just smoke.  It makes it hard to keep target lock.  

 

I suggest you look at what missile tech and missile defense looks like for modern Navies and tanks - because you will see the 'supersmart missile' has countermeasures.

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14 minutes ago, kerbiloid said:

If the countermissiles need to get close, the Xray missile will explode and hit the ship long before they can intercept it.

The original premise says the missiles "will hit in about 2 hours".

Assume similar tech for both sides because nothing in the original post suggests otherwise. If the attacking ship can detect their enemy from 2 hours away, it's reasonable to assume the defender will detect the launch of 40 missiles, and could launch countermeasures that meet the incoming missiles before they are in range of the defender.

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5 minutes ago, DeadJohn said:

The original premise says the missiles "will hit in about 2 hours".

Assume similar tech for both sides because nothing in the original post suggests otherwise. If the attacking ship can detect their enemy from 2 hours away, it's reasonable to assume the defender will detect the launch of 40 missiles, and could launch countermeasures that meet the incoming missiles before they are in range of the defender.

The original premise also means subluminal speed, if they launch the countermissiles in advance, they most probably wil hit the wave of decoys, and 2 hours later the wave of Xray missile will get close and shoot.

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2 hours ago, JoeSchmuckatelli said:

I'm not entirely sure what you are hoping to accomplish, then.

Observation: most adventure/space-battle sci fi is a variation on conventional warfare - simply writ to a different scenario.  This is accessible to people largely because of historical experience with the never ending battle between defensive and offensive technologies.  There is a constant tradeoff and cost to every advantage that can, with a little creativity be overcome or bypassed.  Makes military life interesting.

You seem trapped in a 'Tech can overcome everything' loop.  Not sure how you can get yourself out of that... but I will point out that every tech has limitations along with the capabilities.

 

FWIW - the "Sand Cloud" is just smoke.  It makes it hard to keep target lock.  

 

I suggest you look at what missile tech and missile defense looks like for modern Navies and tanks - because you will see the 'supersmart missile' has countermeasures.

 

I do not consider it a trap.

 

There is a saying that battles are won before they are fought.

At times people are just are too stubborn to accept defeat until they are forced to accept it even when they know the battle is lost... and many other times they do not know that the enemy is better prepared than they thought.

I guess my point is that with torchship style missiles coming after you, the most effective counter other tyan a dedicated lasing ship is missiles of the same type outfitted to with anti-missile weapons.

 

Generally speaking, and this is quite ironic, the more realistic a spacebattle is the more interesting and deadly it is.... but it also gives you far more to defend with too that will work cheaply.

Whereas the more unrealistic a space battle is the less interesting it is, besides being safer too.... with less optiins for defense (why everyone and their mom uses mainly deflector shields for defense in star trek).

Edited by Spacescifi
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