I need a scientifically sound invention (or group of inventions) that ensures that battles fought in space will not just turn into a battle between systems that launch missiles and systems that destroy missiles before they reach their target. I want space battles to became more like classic Star Wars-style battles (which included making spaceships able to survive multiple hits). Is there any way I can make this work?
Computer and Remote Control Jamming
Make tech that can jam remote control signals and computer systems easy, cheap and effective. Think of it as a sort of a kinder and gentler EMP.
Maybe it is a "universal white noise generator" that costs 1,000–10,000 dollars equivalent each. It blocks transmissions at any useful frequency and that disrupts the functioning of integrated circuits by confusing signals between nearby wires with each other. It is effective within a 100 km radius.
It can be sent on a dumb missile to the general vicinity of an enemy ship or missile (a horseshoe or hand grenade class defensive weapon). In addition, there would be one fixed mounted as standard equipment on all major combatants.
This also discourages over automation of space ships — which may make autopilots and the like untenable.
Thus, instead of drones, you need manned fighters and people controlling the operations of mother ships. Electronics that are of any use in battle are limited to very simple circuits with wired connections, and navigation is done with microfiche and projector technologies together with compasses and rulers.
Dumb Weapons And Manned Weapons Rule
Dumb munitions (like laser beams and thrown slugs and dumb missiles and bombs) would have to be sufficient.
Space warfare lasers might work more like lasers in real life by causing something explosive or flammable in the target to ignite and requiring a second or two (at least) on target to be effective against non-organic targets, rather than blowing things up in their own right.
Perhaps antimatter proved to not be technologically viable, and human controlled lasers are fairly effective against dumb bombs and dumb missiles that are highly explosive.
Manned kamikaze missions would work, just as they do in Star Wars.
Missiles are expensive. Space ships are very expensive. Using up expensive things to break expensive things is wasteful. If you don't have effectively infinite resources in space it could be you need to recover their ship after the battle to make fighting (or even surviving in space) over the long term possible. If you know that there is only a limited amount of steel in space you can't afford to scatter the pieces or irradiate them.
If the lasers are accurate and fast enough to hit the missiles and have enough power to destroy them it doesn't make sense to launch missiles that you know are just going to explode near your launchers or worse while still in your launchers.
TL;DR Designer ships will be fast, and fast ships might need fast weapons.
Realistically, you're not wrong.
Spaceships as we know them today do not maneuver quickly, and it will be a very long time before we make fast, maneuverable ships - if at all. There's no real reason to - long-range missiles allow a safe distance from the target, and the majority of resources any fleet might want to secure would be on planets.
However, realism's never stopped anyone. Let's stretch this.
If "designer ships" are made to be fast, these situations may occur. Compare racecars to normal cars: racecars are not practical - they are expensive, burn through fuel fast, and are really only used for sport - and yet we have perfected them. Perhaps a "racecar" spaceship equivalent would fuel the need for speed: everyone would want one, the economy for fast ships would grow, and the technology would be developed in the face of practicality and common sense - just because some people can pay. It's worth noting that it's a lot more expensive to do this with ships than with racecars, but you can use the excuse of "it's the future, I'm sure this tech exists for cheap".
Once speed is explained (see above) simple missile defense systems may not suffice. If you can travel faster than missiles, you may develop faster weapons (think Star Wars plasma guns, etc) and so might your opponents. Battles will be faster paced, and you may see Star Wars-esque scenarios occuring.
Space Time Cloak
A space time cloak essentially allows an object, such as a ship, to pass through any place in spacetime and not interfere with the events unfolding in that place.
Space Time Jumping
Suddenly moving to different points in space and/or time can allow you to move out of the way of incoming missles. To move in space, there are countless ideas about tesseracts allowing for teleportation in spatial dimensions by folding them. In addition, scientists now claim time travel is possible, so moving to a point in time immediately after missles would have passed through the space where your ship was would render the ship unhittable by conventional missiles.
In addition, if one has these abilities to move the ship around in space time, you could also move the missiles themselves, rather than the ship.
Deflecting Missiles by Bending Space Time
Another possible solution would be to bend the area of space time between the ship and the missiles so that the missiles fired at the ship can no longer have a straight path to the ship. Gravitational lensing is a known means of bending space time, so perhaps as the missile is approaching the ship, a bend in space could shunt the missiles' path off away from the ship, or perhaps even back at the enemy!
Making Space Time Impassable to Missiles
If the fabric of space time were altered, it could become unpassable to conventional missles. For example, space time is generally referred to as being like a sheet of flexible fabric--an elastic surface essentially. The missiles must pass over this surface in order to reach your ship. So, if the surface of space time were disrupted so as to be bumpy, perhaps the rigid missils would not be able to conform to the bumps and would be destroyed, just as a car would be destroyed if it were to attempt to drive too quickly down a very bumpy road. Perhaps randomizing areas of space time between the missles and the ship could achieve this effect.
Perhaps the size of the bumps in space time could be rendered so large they become like walls--so abruptly steep the missles simply crash into the sudden 90° bend in space time.
Another idea for making space time impassible to missiles could be to make the area of space time between the missile and the ship infinite in length so the missile runs out of propellent before reaching the ship. To make the missiles path infinite in length, simply (LOL) kink that path into a fractal shape, like a side of a Koch Snowflake. As soon as the missile runs out of fuel, just unkink space time.
Love Missiles Hitting Your Ship
Piezoelectric materials generate energy when mechanical stress is applied to them. If the enemy is using conventional explosive missiles, make the ship have an outer hull of durable piezoelectric material that generates lots of energy for your own use.
If your enemy is using lasers, absorb that blast in less than 50 quadrillionths of a second with a hull made of ultra high speed graphene photodetectors.
the main limitation on manned vehicles is g-force on the pilot, in space anything that has to keep a human inside alive will be laughably easy to shoot down. so you need to change that, either make piloting remote, which could be interesting in and of itself, or create technology that protects the pilot in some way, anything from force fields to nanotech enhancement would work. now pilots can do things and live. most space battles will be about trying to turn your ship to minimize the target you provide and point your weapons at the enemy, think naval battle in 3D with broadside being the opposite of good. now having more ships gives you an advantage you can spread out and force the enemy to expose their flanks. the more ships you can launch and the more kinetic weapons they can fire, the harder it is for the enemy to dodge, since you just can't provide good armor against fast moving dumb projectiles over the entire ship without cooking the crew alive.
upside defensive tactics are few and far between. Vast 3D space mean picket lines don't work, so you have lots of reasons for your characters to be on the move hunting targets. surviving multiple hits would be normal, point defenses and distance means you need to overwhelm the target, not rely on lucky shots. although a personal favorite of mine is the invention of the equivalent of railgun canister shot will make for a very one sided battle.
the other big aspect is in space they biggest thing limiting your fighting is how fast your ship can shed heat and how much heat build up it can tolerate, becasue everything you do generates it and it is hard to get rid of. worse yet radiators which are the best way to get rid of it are very fragile and have to be to work. So whoever can fight the longest before they have to start extending radiators wins. stealth is impossible, you just can't hide in space. worse if you try to make your ship stealthy it just makes it easier to overheat. worse I don't need to hit you to kill you I just need to make you fire your defensive lasers enough for you to cook yourself or surrender.
I really recommend you look at the space war section for the guys over at atomic rockets, they are a fountain of ideas, calculations, and reality checks. http://www.projectrho.com/public_html/rocket/spacewarintro.php
The issue of drive technology
First of all, let's get the question out of the way of whether it will be possible to create ship drives that work like we would expect from Star Wars / Battleship Galactica etc. - fast, agile moving ships. Not limited to boring gravity well trajectories, but being able to travel more or less straight to where they want, at least in-system. Probably combined with some form of artificial gravity.
This is the primary invention/handwave you will want to have in your universe. Without this, as others have pointed out, there will not be much in the way of battle at all. We obviously do not have nor know of any kind of ship drive today that would pass the
science-based tag. Take your pick in order of scientificality... humongously powerful conventional rocket drives, fusion drives, antimatter drives, antigravity drives etc.
For inspiration, look at any of the usual media - BSG (agile small fighters; capital ships restricted to very slow maneuvers combined with instantaneous jump drives of unspecified technology), Star Wars (the same), Star Trek (the same), Elite:Dangerous (the same plus a "middle ground" of non-jumpy faster-than-light in-system navigation), etc.
The issue of scale and intention
No matter what you do, space battles are dumb anyway. As others have pointed out, space is big. Tactics like on earth, using open fields, mountains, trees etc. all simply do not apply. You cannot defend a planet by surrounding it with whatever point-like technology (ships, satellites). In empty space, anything that can move fast enough can move away from any attacker fast enough. Except for destroying planetary/moon-based infrastructure, there's just no point in attacking anything; and that goal could trivially be achieved with dumb near-lightspeed mass being hurled at the ground target.
Especially with Newtonian mechanics (no friction; give one hard burn and then keep flying fast, with the occasional change of direction) it will be exceedingly hard to track anyone.
So this is the second invention you need: ways to track the enemy, FTL radar, "subspace" which is "orthogonal" to normal space, letting your ships "pop out into reality" without warning and all that stuff. Else, any real meeting between two armies would be so unlikely as to kill all suspension of disbelief. Again, this being basically a FTL or extra-dimensional (or both) think, it's hard to think of anything science-based.
I want space battles to became more like classic Star Wars-style battles (which included making spaceships able to survive multiple hits).
You need ships of different scales; small fighters, medium-sized frigates, huge capital ships. This solves your problem of ships being able to survive multiple hits - a small fighter will not pack enough punch to damage capital ships, but a pack of small fighters might just be able to wear a frigate down. On the other hand, a frigate/capital ship might not have the correct weapons to actually hit fast-flying, evading fighters.
Huge ships will be built so they never ever need to get near any gravity well; hence they can have relatively large proportions of mass dedicated to armor plates and other defense mechanisms. They will be sitting ducks, but sitting ducks that can take a lot of beating. Yes, there is the problem of dumb missiles (lumps of mass) thrown at them at higher fractions of the speed of light, but you can make it so that your frigates (and of course fighters) just cannot deliver those. But a bunch of frigates might just have enough conventional firepower to basically tear holes by working together and imparting huge loads of energy in a small location.
So your battles will likely revolve around capital vs. capital or frigate vs. frigate, with the smaller classes of ships trying to bring a decisive advantage, for example by taking out radar dishes, throwing chaff or whatever you can think of.
Ships of the same class will still basically be able to take out each other with single/few hits, but this just adds to the tension (every battle depends heavily what kind of setup the enemy brings in regards to size/number of his ships, and which tactics they employ).
Take a look at the books of Ian M. Banks, he has a nice amount of ship classes, from little few-person-ships to giant almost planet-sized A.I. entities. As a rule of thumb, make it so that each larger class can carry a few of the next smaller class. The largest ones might even construct smaller ones from raw material.
Historically, vehicles are built to allow a certain defensive system to cover a much larger range than the weapon system can directly engage. For one, a artillery emplacement stuck in a concrete bunker can only cover whatever range it can hit with its projectiles. A field gun, while able to have the same caliber and use the same ammunition, might be repositioned from place to place and cover much more than its fixed emplacement counterpart. On the same manner, a spaceship provides the ability to have the same weapon systems that might be fixed to a single-planet, but on any other planet in the reachable universe. So, if you have a dispersed colonization, and not enought production capability to protect all venues of attack that your enemies might use, a defense based on spaceships will allow you to bring weapons to bear at critical places and bring firepower to the offense at the gravity point of your enemy.
When ballistic missiles were developed, the nuclear powers decided to not scrap their bomber fleet. The reason was that a ballistic missile that might be launched accidentally or prematurely cannot be stoped mid-course and so a stray missile launched at your enemy can generate a massive retaliation and escalate the war into a total one. So, the bomber force might be launched, orbit around your enemy, avoiding violating his sovereign territory and be called back if necessary without firing a single shot. This means that your missiles might be stored in lower readyness conditions that might be safer and allow you to avoid accidental use and the escalation of a conflict into war.
So, those two capabilities when combined into a space faring political entity arsenal, are multiplied by the vastness of the universe and the dificulty provided by such vastness due to the limitations of communications without FTL travel. If you launch a missile that is able to come close to the speed of the light, communication wich such a missile, to allow mid-course updates will be hard if not impossible. At the same time, the time this missile takes to reach a certain sector of the space might be too long to allow credible and immediate response to a new threat or a developing situation. So, a space ship is a usefull tool in a more diversified arsenal.
Another consequence of having vehicle mounted weapons is that, while a fixed emplacement is, afterall, FIXED, and it's position might be known in advance by an adversary, a space-ship has the whole reachable universe to hide and ambush your enemies. The existence of interspacial cruise missiles only increases the usefullness of such resource, as if your enemy tries a decaptating first strike against your leadership he will strike your fixed weapon emplacements too, to try to avoid a massive counter-strike. If you have space ships in patrol, this allows you to have a credible second-strike that is much harder to be destroyed because it must be first found and be attacked in order to be destroyed. Better still, your spaceships might be armed with the same interspacial cruise-missiles as the fixed emplacement ones, allowing then to strike at your enemies from any part of the universe without risking being destroyed in a sneaky first strike.
This is not actually the problem of protection, but rather propulsion.
Any ordinary spaceship needs to cross the distance to the target, and space is huge and empty. This means that spaceships glow (IR from life support and all kinds of other radiation from engines and reactors) like a searchlight during blackout. If you want your spaceship to be capable of reaching other planets in same system in less then years, then you need engines that will be easily visible from Alpha Centauri, even with our current tech. Meanwhile, "cold" missiles, whose initial velocity is imparted by launcher and then they travel in hibernation mode until they come near the target where they reactivate reactors/engines/guidance/whatever else, won't become detectable until they are fairly close - you can only detect them with active systems (like radar) or by looking for sudden blinks of stars caused by occlusion.
This eliminates spaceships from the battle
fieldspace, their only purpose is to serve as mobile launchers and nothing more. If you want lasers, autocanons or anything like that to be relevant in space combat, you need FTL.
With FTL you can cross the distance without warning, thus you can't be shot down in transit. You can jump right next to the enemy and immediately open fire with weapons designed for hug-range (in space anything less than thousands of kilometres is pretty much hugging), which in turn forces enemy to equip such weapons, and also forces development of countermeasures against such weapons. Every countermeasure, be it armour, shields, ECM, anti-missiles or sublight engines, relies on FTL to stay relevant. During weeks or months of transit, enemy has ample opportunity to run away (when outnumbered) or use superior numbers to push effective range further than yours (the more guns - the harder it is to block/evade all fire, the longer range - the easier it is to block/evade all fire, thus more guns -> longer effective range), thus overwhelming your countermeasures before you can overwhelm theirs. You need FTL for combat to be anything but one sided slaughter.
It's a bit like trying to attack sniper with a sword. Unless you can teleport or sneak close, it's impossible. Since in space sneaking is not an option, your are only left with teleportation. Or picking up a sniper rifle for yourself, but you don't want that.
If you want battles where it takes multiple hits to destroy a ship, it would stand to reason that attacking weaponry is not strong enough to overcome defensive weaponry.
How About Force Shields?
Force Shields could explain why missiles are no longer used.
Basically, you could have some kind of shields that are very effective against projectiles, which would render missiles (or "torpedos") useless. I think this makes some sense in that explosives on Earth do most of their damage by shockwaves propagating through the air. Obviously not possible in space.
There are Kinetic Energy projectiles (like railguns) that do their damage by smashing into things. Even if you put a shaped charge in front of that projectile (like anti-tank artillery) you would still be basically just shooting molten armament.
If there were some type of ion shield or other force field technology that provided excellent protection against all matter projectiles, that would end the use of missiles.