# Close Quarters Combat… In Space

A simple enough question, but one that Grimmsdottir and I agonized over.

Basically, what would enable close-ranged fighting between space fleets/ships? We both agreed that having gargantuan ships sniping at one another from billions of miles away was no fun, so what would be a good method to force battles to be more personal?

Some ideas we have considered:

1. Powerful phlebetonium shielding that necessitates the use of boarding parties.
2. Minovsky Particles (or an expy thereof).

The harder the science, the better. But if hard science makes this impossible, soften the science instead of merely saying 'it can't be done'.

This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See the tag description for more information.

• @grimmsdottir don't work from questions, bruh. Nevertheless, this was one that we were thinking pretty hard about. – grimmsdottir Apr 15 '15 at 12:59
• When you say Close Combat, are you looking for hand-to-hand melee combat or do you just want ships close enough together that it's more of a dogfighting situation? – Dan Smolinske Apr 15 '15 at 15:21
• @DanSmolinske Dogfighting. – Feaurie Vladskovitz Apr 16 '15 at 3:19
• I've actually had this conversation/discussion before, and science makes sniping pretty much the most effective weapon, AFAIK. But more like sniping with an incredibly accurate shotgun. You get a couple hundred/million small, dense particles, accelerate them to near-light speed, and there's not much effective defense against that besides "don't get hit". – Wayne Werner Apr 17 '15 at 15:29

As a general rule, it seems natural that you would want an opponent as absolutely far away as possible. The further away they are, the fewer tools they have to hurt you.

However, there are a class of situations that demand rapid feedback to be effective. These show up when there are many unknowns that must become known before your attack can succeed.

Consider a randomized chaotic shield. If you just bombard it, you can see that, statistically, it defends against your bombardment. However, what if we don't have a way of making it perfectly random just yet? What if they are chinks in its algorithms which could be exploited? What if you could "walk it off" the spot you want to hit before you actually hit it?

This is not actually all that far into science-fiction. These sorts of things would actually start to naturally come into place if your shields were trying to observe and react to the oncoming salvos. It's rooted in chaos theory.

In Chaos theory, there is a concept called Lyapunov Time. Roughly speaking, a chaotic system acts roughly predictably under this time constant. However, after that time constant, the amount of unpredictability grows exponentially.

It takes time for light to travel in space. If you get feedback on "what state the shields are in" that is 2 minutes old, and the Lyapunov Time for those shield is 1 minute, you have virtually NO idea what their state is when your next salvo lands. You might as well be fighting blind

However, get down to within a light-minute from the opposing ship, and now you can start to see a little bit of predictability out of the opponent's shields. You see openings, but you can't leverage them because you're too far to launch a salvo.

Now get really close. 15 light seconds, 10 light seconds. Now you start getting close enough where not only can you predict what the shields will do, but you have time to respond and attack with that information. Now those shields are a lot less of a threat than they were before!

Interestingly enough, one can use a very similar modeling approach to explain why, in real life combat, it is so important to have ground troops going door-to-door in some particularly chaotic situations.

• Wow I like this one. It even sounds so... Science-y. Lyapunov Time! – Feaurie Vladskovitz Apr 16 '15 at 3:23
• trouble is, now your big ships are so close, they can be easily blown to bits by massive salvoes of big guns. What you want then is to keep your big ships far away and send in the swarm of more expendable fighters... Galactica style. – gbjbaanb Apr 17 '15 at 11:40
• @gbjbaanb awesomely enough, that is EXACTLY what I want. – Feaurie Vladskovitz Apr 18 '15 at 14:08
• @gbjbaanb I intentionally avoided the swarm of fighters, not because it is wrong ,but because it complicates the issue. Galactica did not quite cover why swarms of little ships are a better choice. There are very valid swarm models which actually fit the chaos theory description I put forth perfectly. They just take a little more effort to model in your head. The eventual answer should be that salvos against the ship are "deflected" via shields, swarms, good judgement, or whatever. Shields were the easy to visualize version, I think your swarm idea is the full-on version of that ideal. – Cort Ammon Apr 18 '15 at 17:18
• That just says to me you want smart missiles. Launched from smart drones capital ships. – Aron Apr 20 '15 at 1:10

## Interference Shields

An impenetrable shield would cut down range drastically by simply not being passable by weapons fire. If you wanted to shoot, you'd have to be inside the shield. Problem is; you can't normally get there, because any shield that blocks out weapons fire would also block out ships.

Potential solution: an impenetrable shield that interferes with other shields. If you have two shield generators and their shielded areas touch, they start overlapping and fizzle out over the contact area. This means a shielded object can enter a shield, and once it does, is free to open fire on anything else also inside said (combined) shield.

This allows you to fly into close range and then open fire, but at such short distance that ultra-firepower would basically just destroy you as well. One requirement is that the technology to create the shield be incredibly expensive, otherwise there's no reason not to simply throw out shielded missiles.

The results of such a shield on a capital ship would be interesting, to say the least. For example; if you destroy the enemies' shield-ship, they will be trapped inside yours. This may or may not be a good thing (as they'll either fight to the death or surrender immediately)

It also means fleet tactics will be common, since any ship without a shield-ship nearby will be a sitting duck (but only to enemy vessels that are also operating outside a shield-ship). You also cannot reliably split or merge fleets into a portion smaller than a single shield-ship and its escorts, since the other ships are trapped in there with you.

You could only dock at a shielded spaceyard, or a planet with a massive planetary shield around it (to protect from enemy raids and the hazards of space, like asteroids).

If the shield works by simply inverting the speed of any object that collides with it, you also have a good argument against rapid-fire cannons to simply shred everything in the shield; the shells and scrap from the vessels would bounce off the inside of the shield and turn the entire bubble into a giant deathtrap.

Ships would need enough armor to withstand the floating debris that is left at the end of a fight, and they'd need to be careful with their guns because missing is risky.

Alternatively, you could say that interference is only possible between two shields that are roughly the same size. Imagine if the shields dent inwards on contact based on their relative size difference, before starting interference. Then a ship with a very small shield bumping into a very large shield would have its shield dent all the way inwards, where it would destroy the shield generator, causing the ship to be destroyed. But a much larger ship would have less of a dent (and more space to absorb it) and after a short push, the shields would start interfering.

This allows your shields to act like semi-solids (or plasmas?) and reminds me a bit of soap bubbles. You still can't have shielded missiles piercing a vessels shield (both because a missile has a very small shield and because the high speed means the shields won't have time to start interfering before you slam into the other one) but it does allow shields to be much cheaper.

This will change the dynamic of your world quite a bit, so it depends on the other goals of your story-world which is better.

(Credit for the alternative goes to Falco)

• How could you generate the shield? What would it be made of? – HDE 226868 Apr 15 '15 at 21:34
• ionized phlebotinium particles, of course. – STT LCU Apr 16 '15 at 7:03
• Shields don't have to be insanely expensive - it would be enough if the interference only works, if you own shield-generator is about as big as theirs. So a huge Ship with a giant shield-generator can only be attacked by an equally large vessel. While smaller ships can also have shields, but these can be attacked by equally sized ships/missiles and will just shatter on contact with the giant ship shield – Falco Apr 16 '15 at 12:19
• @Falco: I like that idea a lot. I edited it into the answer. – Erik Apr 16 '15 at 12:28

To stay within the bounds of plausible science, I will eschew the concept of impenetrable shields.

Unguided projectiles are rather useless if the target has sensors with enough resolution to spot the incoming missile at distance - they can just dodge or deflect it. This would also require the target to be relatively stationary for a very long time and the aggressor would need an exceedingly precise launcher to actually hit anything. Even shotgun tactics are unlikely to work, because space is big.

Guided missiles will be vulnerable to countermeasures. Multiple ships (or just a deployed decoy) painting the incoming missile in whatever EM ranges the targeting system uses will effectively blind it, rendering it as useless as an unguided projectile.

Get a little more energetic with your countermeasures, and short-range energy weapons can kill the missile - burn off the sensors or slag the maneuvering thruster nozzles and it is effectively neutralized. Presuming the target is not relatively stationary, the missile probably wouldn't even be on a collision course anyway - just let if fly harmlessly past, but a little more energy would deflect it onto a different trajectory just in case it might still pose a threat (large explosives set to the last estimate of target's location). It may be possible to fire massive volleys of guided missiles in the hopes that the target cannot cope with them all. Unfortunately, your missiles still have a long distance to travel while vulnerable to countermeasures, and those that survive get close enough where shotgun tactics will work for the target destroying them. This also requires huge quantities of munitions to attempt (scaling up with how good the countermeasures are, with the advantage to the defender), which would be both cost prohibitive and severely limit your choices as you blow it all on one shot.

I would expect energy weapons to be far more popular than projectiles, simply because you have to haul around all that mass for your projectiles, but energy weapons do have an effective range. If you try attacking from too far out, the beam will be so spread out that the energy imparted on a square meter basis may be too low to be effective. If the target gives itself a little spin, so the patch of hull being hit over time keeps changing, you might not be doing much more than slightly warming it up. Of course, if you have a high enough energy output, it might be lethal even if dispersed, but that would probably take absurd amounts of power.

Closing distance reduces the time a target has to dodge or counter incoming missiles (physical ammo is limited so make each shot count - don't fire until you can see the whites of their eyes), and allows for a much tighter focus on energy weapons (imparting more energy per square meter to the target).

• This is the most plausible answer. – PyRulez Apr 16 '15 at 23:07
• "because space is big" holds true today - and yet shotguns are surprisingly effective. The size of space itself isn't really what defines effectiveness - it's ability of the target to occupy a different space before getting hit by the projectile(s). Given current tech, rapid acceleration is pretty expensive in space, though. – Wayne Werner Apr 17 '15 at 15:32
• @WayneWerner The volume of space you would plausibly need to fill to hit your target from a few hundred thousand miles away, even assuming projectile speeds from a grossly overpowered rail gun, would require so many projectiles that any other means of attack would be better than firing unguided weapons, even in large scatter-shot fashion. Hardly any thrust would be needed to make the volume of space in the cone of potential locations so huge as to be practically impossible at anything but very close range. – pluckedkiwi Apr 17 '15 at 20:04
• It's possible to accelerate a large mass and then make it scatter at the last moment, like a MIRV – Wayne Werner Apr 18 '15 at 6:25

Missiles in space aren't are useful as you might think

Here's a NASA report on how nuclear weapons would behave in space. The major points are:

First, in the absence of an atmosphere, blast disappears completely.

Second, thermal radiation, as usually defined, also disappears. There is no longer any air for the blast wave to heat and much higher frequency radiation is emitted from the weapon itself.

Third, in the absence of the atmosphere, nuclear radiation will suffer no physical attenuation and the only degradation in intensity will arise from reduction with distance.

In short - no blast, no heat, but lots of radiation. If your ships have very good radiation shielding (which would be very useful in space outside of combat, too) then only a direct hit or near miss is going to affect you. Non-nuclear weaponry will be even less effective - with no blast or heat transfer, a direct hit would be required for any damage to happen.

As others have mentioned, it's pretty easy to come up with ways to disable long-range missiles, let alone simply causing them to miss. If a ship is close enough that a missile can't be disabled in time, it's likely that both ships would be affected by the radiation of nuclear weaponry.

This also means that small fighters can be very useful - they would be very hard to hit directly with missiles. They would also be able to pretty much completely mitigate EMP damage - if an EMP missile is launched, electrical systems can be shut down into a mode that prevents any damage and then rebooted after the EMP has passed. These fighters would allow you to get missiles close enough to be deployed without being disabled before arrival.

A salvo of missiles at close range is another potential tactic, though more risky - if you blow off a chunk of their ship it might come flying straight at your ship. A close-range salvo would probably use non-explosive missiles to avoid this - instead of trying to blow up the enemy ship, you'd be simply trying to punch holes in their hull.

• IIRC EMP is created by interactions with the atmosphere and magnetic field, which also don't exist in outer space. – March Ho Jul 11 '15 at 5:32
• @MarchHo interesting. That would probably mean a nuclear blast would not create an EMP in space. The EMP missiles I mentioned would have to use something else to create an EMP. – Rob Watts Jul 11 '15 at 19:51

Science has absolutely nothing at all to do with the answer. It's a question of resources.

If you need to capture an objective intact, then you send in regular troops. If you don't then you destroy it while you are as far away from it as you can be. Today's wars often start with pinpointed strikes launched from sufficiently far away that the enemy can't counter them; only to be followed up later with pacification of the populace with "boots on the ground." In cases where that pacification isn't necessary, then the boots never hit the ground.

There's a reason the phrase "Nuke it from orbit. It's the only way to be sure." is a thing.

Close combat to take over land or equipment that can be bent to your side's purpose may make sense, as long as the value of the land or equipment exceeds the costs of the potential losses in taking it. If not, then the fall back is simply to deny it to the enemy and, therefore, hitting it from far away.

If the technology is sufficiently alien then there might not be a reason to grab more than a couple ships or space stations for research purposes. If the alient planets aren't fit for human habitation, or necessary for human needs, then there won't be a reason to capture them.

the tldr; is that there has to be an actual reason for them to get up close and personal. Otherwise you're just spinning a "because I said so" story.

I'm surprised no one mentioned this, but a (to me) obvious solution is to depend on sensor deflection, scattering, or deception technologies (the equivalent of stealth, but adjusted to meet the parameters of your situation). If you can't see what you're shooting at, you have very little chance of actually hitting anything. This only applies to ships that have these technologies built in, but it would require close range, potentially very close, in order to get any computer-controlled targeting systems to work at all.

Missiles can be equipped with onboard sensors, meaning that they could be launched in the general direction of a known target even if the exact location of that target is unknown to the launching ship. You would depend on the missile to find its target on its own. The further the missile travels, the less payload it would deliver (assuming that fuel contributes to and potentially makes up the entirety of the payload), and eventually, the missile would turn into drifting space junk or a moving, dumb space mine. Since you're dealing with potentially heavily armored or shielded ships, missiles must be equipped with potent payloads. They may be much more expensive than energy weapons and they are usually limited in supply. Also, a deflection shield would often easily avoid missile damage. Once a missile is deflected, the attacked entity would easily be able to track the source of the missile and launch a counter-attack, so missiles would be useful for long-distance ambush attacks against small enemies, but failing to destroy the enemy would turn the missile into an effective invitation to a counter-ambush (at long distances, the initial attacker might not know for sure exactly where the target is, so a counter-ambush remains a possibility).

Energy weapons dissipate with distance. This effect could be drastically increased by dissipating shields. The shield itself would only be effective against energy weapons, but it would be capable of dissipating such weapons while potentially recycling the energy to increase shield strength. Close-range would be the only option in this case because natural dissipation is reduced to a point that would allow at least some of the energy weapons through the shields.

• The flipside is that you'd have to be really close just to know the enemy is even there. – NotMe Apr 15 '15 at 20:05
• Why do you need constant acceleration for your missile in Space? Once you have sufficient speed the missile will not slow down in a vacuum, so you only need fuel for steering! – Falco Apr 16 '15 at 12:31

Let's first make it clear: dogfighting in space is extremely unlikely with current technology due to immense fuel requirements: quick maneuvering -> extreme changes of impulse -> burn tons of fuel (comparable to mass of the craft) -> need to take more fuel onboard -> heavier craft -> need more fuel to change impulse... If there is no major breakthrough in high-impulse propulsion tech, there'll be no dogfights in space.

Also, orbital physics puts some serious constraints on possible maneuvers (if you played Kerbal Space Program, you know it), BUT it also makes quite awesome possibilities for hi-adrenaline low-orbit tactics without requiring tons of fuel (imagine Gravity with fighters instead of debris). If the planet is small and dense, its low orbit will look like a hi-speed circular death race track! (It'd be an interesting side-research to calculate which celestial bodies provide best conditions, or to choose physical parameters of a planet when designing a fictional one). As a bonus, it can provide "civilian background" to discourage from inaccurate shooting.

Also^2, here is some neat analysis on how physically realistic space battles may look like (you've probably read it, so just in case). And here is some fruitful discussion on dogfighting in space.

Finally, consider dogfighting inside a gas giant atmosphere. Ice giants' atmospheres contain more methane and ammonia than Jupiter-class giants, which can probably be used as fuel in an appropriate engine (that's a topic for a separate research).

Still sticking to dogfights? All right, let's keep it more or less hard-sciencey.

Current spacecrafts are extremely fragile. If a dangerous space debris is detected in the path of the ISS and it is too late to maneuver, the lids on Cupola are closed, solar panels are rotated in parallel, the crew gets into spacesuits and prepares for emergency evacuation in Soyuz. There is some layered shielding on the most vulnerable parts of the ISS, but it can only protect from small debris.

Armor is heavy and bulky. Even the battle-oriented spacecrafts of near future probably won't be strong enough to survive a direct hit of a missile, a volley of projectiles or piercing laser shots. Larger ships may afford some multilayer graphene shielding, but still, most of the time they'll bet on reflection, deflection and maneuvering ahead of time.

Spaceships are easily seen against space background, either visually, or in IR, or in radio. The closer we are, the easier it is to detect, and the harder it gets to stay stealth. A bit harder when against a planetary background.

The closer are the spaceships, the more weapon possibilities they have:

• Over large distances (light-minutes or more), only relativistic weapons are feasible. It is a battle of AI-guided prediction modeling, small randomized maneuvers and lots of patience. Assuming we have a good low-dispersion hi-power laser/maser/particle-beam. (Btw, consider a story with battles of AI predictors and an exploited/faulty RNG which gives not-good-enough random maneuvering, putting the ship in danger).
• Medium distances allow for mass drivers, which accelerate small projectiles to almost relativistic velocities. Deploy several thousands of them into the predicted target position and around it. And again, have some patience and a good prediction model/algorithm.
• Close encounters would allow using guided/smart missiles without waiting for months, but they are heavy to carry around and to accelerate, can be countermeasured, and it is probably easier just to deploy huge swarms of them from the mainship at a distance and leave them do their job. Maybe even outfit them with their own beam weaponry, turning it into a drone fight (which is also easier, cheaper and safer for the crew, although less heroic), or shrink them down into a micro/nanoswarm.

The closer are the spaceships, the fewer defense possibilities they have. Missiles, drones and other slow macroscopic objects can be taken down/redirected/blinded with beam weaponry ahead of time. Volleys of relativistic bullets are much harder to dodge, so we'll have to rely on random maneuvering and those puny armor sheets we have. Hence, mass-drivers can be used in both medium and close encounters (I just can't imagine an efficient countermeasure besides maneuvering, armoring and blinding/disabling enemy ship). As for beam weapons, besides maneuvering, we may try reflective (in appropriate wavelengths) surfaces, but another possibility exists: if there is only one source of enemy fire, we can shoot a deflector missile in their way, to change beam paths ahead of time (gravity lensing itself may be enough to make the beams miss). Or use dispersive cloud countermeasures.

Maneuvering, design and CM. Since maneuvering is the most reliable method of long-term survival in space battles of any distance (and since we have soften our fuel requirements), the smarter and more unpredictable we are, the better (AI can do the job, while keeping the crew safe in the mainship, but again, not too heroic). So, the ships should be light, be outfitted with enough reaction wheels to quickly turn around, may have several maneuver engines and several weapons looking in different directions, and be filled up with all kinds of countermeasures (jammers, optical/IR/MW/radio decoys, dispersive clouds, beam deviators, anti-missile beams, drones/nanoswarms, etc.) to get closer to each other. The ships should probably be of some fancy shape to make barrel rolls in 3D more efficient (no need to be aerodynamic). And those manned fighters should better be accompanied by numerous drones.

To sum it up:

There may be some situations where close encounters are possible (limited space inside some asteroid cave, for example) but there aren't many of them in outer space. Low-orbit is more feasible. Or maybe a scenario of protecting a space station/habitat from non-destructive invasion/boarding.

There are numerous technologies that would prevent ships from getting into a dogfight: algorithms of control and prediction, long-range beam weaponry, AI-controlled drones/swarms. This can be facilitated by prohibiting them in your scenario (religious fear of AI, "undignified" use of drones and long-range beams etc.).

And of course, some technologies are just not advanced yet to provide a dogfight: economical high-impulse propulsion (the most problematic one), efficient shielding, more rigid spaceships, cheap space launches / interplanetary travel, efficient weapons for space usage.

Also, remember: ships are small. Space is immensely huge. Consider sticking your spacefights to some locations of interest (as localized as possible; otherwise they'd just lazor down each other from afar).

• This is a pretty fantastic answer. Probably the most accurate, scientifically speaking. Unless you magic up some new tech, spacefights are actually going to be pretty boring. But I really like the idea of using gravitational slingshots as a way to make things more interesting. But basically, I think space battles (with science) would be long periods of extreme boredom, punctuated by brief excitement. – Wayne Werner Apr 17 '15 at 15:43

It depends on the level of technology

Low Tech

Like knave mentioned, if the tech isn't that advanced dodging becomes relatively easy at long ranges. However every single shot/attack and dodge/reaction is costly, making long range combat horribly not cost/effective, this would lead to closer range combat, but high risk as changing course vectors, or "dog-fighting" can not only exact a huge toll on resources but also damage the ship. Fights would be won by extremely brilliant planners like a game of chess where it's all about who place themselves in the best close range position for near-kill shots. Ships would be heavily armored (close range combat) not only for protection but also for strategic purposes, allowing the ship to take X amount of damage for it's own destructive attack to take place at the best opportune moment

High Tech

Not much point in having close encounter battles unless stealth is involved OR the goal is to capture and not to eliminate. The high level of technology would mean even though in a close quarter battle one of the sides probably gets disabled early on, they still retain fighting capabilities at short range for when the attackers close in on them to capture/pillage/kidnap them. High maneuverability Bombers are also a viable idea but would mostly be tiny fighter vs huge ship fights (possible launching its own fighters to intercept). Either that or a cheaper solution to building huge high tech long range weaponry ships, much smaller ships equipped with cheap to manufacture short range high power weaponry. Their strategy would generally be to approach bigger ships undetected to immediately make use of their weapons before the bigger ships can fire on them.

I would give each fleet some sort of large force field carrier, that shields the entire fleet from sniper ships. This would force them to get up and close, entering the force field before even being able to attack. If both parties would have such carrier ships their would be a massive close quarters battle at each battle, trying to destroy the other shield so that the sniper ships can destroy the enemy fleet.

Another idea could be awesome ship manoeuvrability. Rockets would be easy to deflect or shoot out of the sky so I guess the sniper ships would mainly use beam weapons or mach launchers. From the large distance apart I think it could be possible to have ships be fast enough to dodge most of the attacks. This would result in an endless dance between two parties and as the battle goes on they probably would go in for the kill at some point.

• I don't think that traditional science-fiction force fields fit the hard-science criteria so well, though the second paragraph is absolutely good. – HDE 226868 Apr 15 '15 at 21:35
• Isn't boeing making some sort of force field system already? – Robin Apr 16 '15 at 12:36

Simple long-range scanning would allow your ships to see and therefore avoid or destroy any incoming missiles, torpedoes etc. Anything except lasers, and dispersion means those are ineffective at long range anyway. Ships have to get in close to not telegraph their attacks.

If you're looking for big flagships and little fighters trying to board them, the simplest explanation is that there are no weapons that can bring down an entire cruiser. Pinpoint lasers, after all, are only damaging a single pinpoint, and wouldn't be noticed on a hundred-meter ship, let alone five hundred or however big you're picturing. At close range, any missile powerful enough to cripple your enemy's cruiser is going to severely damage yours as well. So the only practical way to disable a cruiser is to board it and incapacitate the crew.

The only tiny voices of reason you have to silence are the ones coming up with more practical superweapons. :)

I think most fights would be close quarters in space. Assuming FTL travel isn't possible and distance must be traveled linearly. No wormholes or other methods to 'cheat' FTL travel. Then most fighting will be done by drones. Either AI or remotely controlled.

People are ludicrously hard to transport. We are easy to transport in that we can perform complex operations in order to make adjustments mid-journey. We are difficult to transport in that we require protected environments, heat and pressure. We also require sustenance and we expire quickly.

So, why are people being transported across space and why don't other people want those people to be transported across space?

If you can't get an answer to that, then all fighting is done by drones and against drones. Drone's can be small, light and agile. Any shots from further away could be easily dodged. All fighting must be close range just to hit another drone. Anything large enough to be hit at range would be large for a reason (cargo) and would be better to be hijacked by a hacking drone... which could be small enough to avoid all long ranged attacks.

• Easy answer: You AI is not good enough for drones! If you're dealing with huge distances you cannot effectively command your drones because of delay (try playing with a ping of 100000 ) and potential jamming from you enemy. - If your drone is completely autonomous, there will be software bugs which may give the enemy an option to take control of them and turn you army against you. And you won't even know it with communications jammed... So you want people close to control you drones. – Falco Apr 16 '15 at 12:35
• This answer; drones, from start to finish, for that whole thirty seconds of battle. Otherwise you never saw it coming, from orbit. – Mazura Apr 17 '15 at 12:58

Battling from the longest effective range only makes sense if destruction of the enemy is your objective.

If ships carry highly valuable, cargo, crew, components, etc. then you need combat to be much more precise. In fact, this is the only reason a ship would bother with a boarding party too.

One SF series proposed that FTL took a human with very special and extremely rare genetics to make an FTL jump. In such a Universe, that human would be the most precious commodity and many engagements would start with closing to a range in which fire can be very judiciously used to cripple and not destroy opposing craft. Many such actions would end with a boarding action to capture this psionic jump enabling person.

Another priceless (or at least pricey) commodity might be a cargo of quantum entangled particles. You could postulate that they would be useful in communications, ciphers, etc.

Or magnetic monopoles (none have ever been found, but they would be highly valuable if they were found).

Perhaps humans are rare and we need to preserve their genes too.

The point is high valuable and fragile cargo would require ships to not engage in combat trying to completely annihilate each other.

Or it could just be a set of war conventions that both sides follow.

• Doesn't FTL violate hard-science? – HDE 226868 Apr 15 '15 at 21:36
• No more so than the phlebetonium shielding suggested by the OP. Besides FTL wasn't the point of my answer. My answer was that priceless & fragile cargo (like psionic women postulated in the SF series) would require every action to be a boarding action and would usually require close up combat so the weapons don't hit crew compartments. – Jim2B Apr 16 '15 at 3:38

For whatever reason close-contact is necessary, why not use remote probes? For Dune shields that block fast objects, a smarter torpedo drone; if explosives don't work or contact is needed for the canopener, use a drone. Think swarm of bees, not one lion.

To get past that, you need a requirement of both contact and large mass. The frigate can't deploy anything smaller because it must be as big as a frigate.

Maybe the shields can only be breached by similar shield generators with power and mass behind them. Real inertia can be required to anchor the effect. Or applying the field to too-small of a ballest will destroy it, as mass is needed to soak it up.

If technology doesn't work, use politics. Like medeveal heraldry, it's all about the players and personal posturing. You're putting on a show for your subjects, rivals, and allies, not just stopping the ship. Add to that the people are backed up or immortal or flying telepresence or something, so just blowing it up remotely would not do much good.

Ships are expensive. People aren't.

It takes years of effort and trillions of dollars to build a gargantuan space battleship with all the latest obscenely destructive toys, but it takes only a few months and a handful of dollars to train a combat grunt with a pop-gun and a can-opener.

If every battle started with the commanders on both sides wanting to come out of the battle with more ships than they entered it with the fighting would switch from big ship-to-ship engagements to close-quarters combat between boarding parties.

This situation would only be encouraged if ship weapons where so accurate and devastating that the only outcome of any ship-to-ship shootout is mutual destruction.

So we'd end up in a situation where massively armed ships are too afraid to fire at each other in case they damage an expensive prize (or get instantly annihilated themselves by returning fire) while boarding parties are favoured as the first line of attack.

I know this answer is not exactly what the OP wanted (no actual close quarters ship-to-ship combat) but I think it's an interesting take on the problem.

• When a piece of wargear costs so much that you are afraid to lose it, then that wargear is often replaced with something else to do the job. In this case a ship is meant to be placed in harms way. Never mind that numerous wars boil down to "chess" like matches where the losing side will normally surrender when the odds are really stacked against them rather than just shoot it out. – NotMe Apr 15 '15 at 20:21
• Ships are expensive. People aren't. That tends to change, very quickly. There are still people alive today who remember, from personal experience, the days when the expensive part of computer programming was the CPU time to build and execute the program. (Computers were expensive; people were cheap.) Then a few decades of progress tackled the problem, and now hardware is only slightly more expensive as the sand it's ultimately forged from, but programming has evolved into a highly specialized engineering discipline whose specialists can easily command a six-figure salary. – Mason Wheeler Apr 16 '15 at 17:05

Make Iron Man a real thing

If energy sources are capable of being small enough to enable a superhero sized problem for opponents, than the large mass and inertia of a ship becomes problematic. A skilled soldier in a wild suit of powered armor that can track the barrels of a laser weapon and always dodge makes the laser kind of useless. Missiles pose no threat to someone carrying a laser sufficiently powerful to destroy them. If you're okay with shielding, than inertial coupling shouldn't bother you too much - this would allow the guy in the suit to accelerate and decelerate at rates that would typically liquefy a human brain. Having a small target makes any one of them difficult to detect, and fielding thousands of them and making them physically difficult to see - say, a mirror finish for example - would hose up just about any scanner or computer vision system. I could imagine this becoming a dominant platform for combat, especially since it could take these large, incredibly valuable ships mostly intact.

• doesn't have to be a human-shaped powered suit, think Bablyon 5 starfighters - very small and maneuverable, not much bigger but with appendages for thruster jets and guns. – gbjbaanb Apr 17 '15 at 11:27

There's also a science-free way to force close-quarters fighting: raise the stakes of missing your target to an unacceptable level. Fighting in an area surrounded by civilians and bystanders means you can't afford to miss your target. Doing so means you have a good chance of hitting a friendly target or non-combatant. Launching attacks from far away means your target has more time to dodge and cause you to hit your own forces, or some unsuspecting target jumps into the path of your weapon. The only way to ensure that you hit your intended target is to get close enough that you have no chance of missing.

For a space battle, you'd need a setting like an environment filled with civilian vessels, a crowded star system with many inhabited moons/planets visible from most any direction, densely packed satellites/probes that perform some vital function (like enabling survivors to get home after the battle), a powerful neutral faction that neither side wants to anger, etc. You can do the same thing in a less target-rich environment if both sides have a tendency to use human shields, but that's typically not a quality attributed to "the good guys" so it may not fit your story well.

You don't need any special tech like shields for this. All you need is for missiles to not be very effective and light-speed restrictions do the rest.

At the speeds and distances spaceships operate at, dodging is ridiculously easy. You just vary your engine output using a random generator (so that instead of just going at 100%, you vary from say, 95% to 100%). Now your ship isn't defined as a single, predictable spot - it's now a giant probability cloud of targets, and your enemies can spend all day trying to pick you out and never touch you, or only get glancing hits. The closer you are, the more you vary your speed, and you start adding directional changes. Then they have to get extremely close to reliably target you. As long as you're unpredictable and far away, you're basically completely safe.

There's a couple of counters to this strategy, of course:

1. Effective missile tech. This lets someone throw a guided weapon in your general direction and let it course correct later. So you need to have it so that anti-missile tech is good enough that that's a losing proposition.
2. Cheap ammo. If ammo is cheap enough that your enemies can afford to take tons of pot shots, your probabilistic safety net goes away. Ammunition needs to be limited and relatively expensive so they can't afford to just blast away.
• cheap ammo isn't an answer - if you're only one light-minute away, the probability area you have to saturate with cheap ammo will be several hundred kilometers in area. (depending on ship speed capabilities). The only answer is autonomous missiles or... piloted 'missiles' that fire ordnance when close enough to be effective. – gbjbaanb Apr 17 '15 at 11:30
• Assuming that missiles will be able to acheive significantly higher thrust to weight ratios than ships - and they will - dodging is not easy if you fix the vectoring problems of not having air. If they can't beat the thrust to weight ratio, nobody will field missiles - ever. – Sean Boddy Apr 18 '15 at 20:24

An alternative theory: simple inertia and sharp edges. Think of it as like the tentacles of a jellyfish: designed to damage and kill. Making the wings into essentially knives could have ships actively trying to come to close-combat situations (with the added benefit of, if you do tear a hole in the hull, you have a really nice place to board the enemy ship.)

It could be a matter of resources. Missiles are expensive, flak is cheap, and has the added bonus of deflecting lasers. So if one ship can surprise another ship then a missile might take it out, but that's pretty hard with sensors being what they are. So most of the time the ships have to get pretty close to each other to fight effectively.

And as others have said, if you nuke the enemy ship then you won't get any plunder. Resources again. weapons, ammo, slaves? Not to mention having another ship to add to your fleet.

In Short: ECM

We have this today, and it's safe to assume that it will become more effective with time along with weapons and guidance technology. Combine that with the relative lack of effectiveness of proximity detonations (mentioned earlier by Rob Watts), and you have a situation where 'dumb' projectiles fired from within the range at which the opposing ship, based on it's size and acceleration potential, cannot displace itself sufficiently in time to avoid it, are the most effective means of attack. This range - let's call it 'point blank' - can be extended through salvo fire (firing a spread of shots to enlarge the area the opposing ship must exit before the shots land to avoid being hit by at least 1), and is also farther against larger ships and closer against smaller ones (since a smaller ship would need to displace itself less to avoid fire directed at it).

Salvo and Massed Fire, Ship Design and Size Considerations

You would end up with a metagame of warfare where ships are built as small as reasonably possible for their role (true today for the same reasons) and are equipped with multiple turrets of sufficient caliber to cause debilitating damage with a single hit so that salvo fire is possible (true in recent history where unguided weapons were king). You would likely also end up with a tactical need for smaller craft - be they manned fighters, drones, etc - to provide screening for large ships so that the larger ships can maintain distance from faster, smaller ones because, being larger, they need more distance from the fight than smaller ones to avoid being hit. Those large ships would then need extremely high velocity weapons to extend their own point blank range against their targets - thus the larger vessels would likely use energy weapons where they can more easily provide the huge power and discharge rate requirements while simultaneously negating their primary weakness against projectile based opponents. Smaller ships would use density/volume of fire of projectile weapons to achieve their tactical aims.

Missiles would be useful close-in where they have sufficient fuel for terminal guidance (there is no atmosphere for aerodynamic control surfaces, so all maneuvering uses more fuel) - if they must burn at a distant target, they will be 'coasting' there to retain fuel for terminal maneuvers, and the target will have time to accelerate itself to avoid the missile's available delta-V.

Fighter Support is a Necessity!

An example fighter: ~800 pounds, H2/LOX fueled, ~4000m/s delta-V: Carries 6-12 6-10lb kinetic kill missiles, guided by radar provided from a carrier vessel (the fighter itself is too light to have such equipment on board).

Another: Combating the weaknesses of the above in a heavy jamming environment, a 'heavy figher' could become a gunfighter primarily, relying on 2x 4000rpm miniguns of 20-25mm caliber to provide a huge 'wall of fire' to take out smaller craft (this can be mass fire from several fighters), and using guided/unguided missiles for anti-ship purposes. It would carry its own radar and likely be He3 fusion powered with Ammonium as a working gas for high delta-V while still providing sufficient thrust.

You could flesh these out further, but these are examples that I've used in a similar setting.

Let us assume... this future civilization was able to achieve FTL travel.

BUT

Everything else was bound by the universal constant. I.e. the speed of light in a vacuum or ~300,000 KM/s

THEN IF

The spaceship is close enough to see by any means of detection utilizing electromagnetic radiation (which is still bound by the universal constant) not to mention there will be a delay when using weapons that are bound by the universal constant as well.

For example:

DISCLAIMER: I am using lasers as an example because I am going to assume that lasers are going to be travelling at light speed or 300,000 KM/S

Two warships are engaging each other with laser weapons (which travels at a rate of ~300,000 kilometers per second) but their distance from each other is about 1 light minute (~300,000 * 60 kilometers): then by the time Ship A sees Ship B visually, or using any other scanning technology that relies on light/radiation, you will only be able to determine where Ship B was exactly 1 minute ago. Then if you fire a laser (which travels at light speed) to the position where Ship B was 1 minute ago, it will take another minute -or a total of 2 minutes from detection to impact- to hit the point where Ship B was 2 minutes ago. This would only work if Ship B were not moving.

So what if Ship B was moving? Of course, Ship A could observe Ship B for 2 seconds and calculate the trajectory of Ship B and fire a laser at where Ship B will be in 2 minutes. This would only work if Ship B does not figure out that any change in it's trajectory during the 2 minutes from when Ship A first spots it; will result in a miss. It would be common sense to start randomizing it's course when warships find that they have been detected.

BUT

As the distance closes between ships A and B, the time it takes to lock on to a target and fire a laser pulse that will impact a specific point will decrease until it becomes less than the ability for the other ship to randomize its course and be able to "dodge" laser beams based on this principle. If lasers are no fun, then kinetic and ballistics weapons will be assumed to be travelling slower than light speed (as any object with mass will require infinite energy to be propelled to light speed).

TLDR: It comes down to how fast your weapons are able to reach their targets as opposed to how fast the target can change it's course. Even lasers do not travel at infinite speed. So you can tailor your desired "engagement range" by limitations on how fast your projectiles will travel versus how capable the opposing ship will be able to detect the incoming projectiles and maneuver out of the way.

There are a lot of cool sciency explanations here, and I guess that was the intention, but I would like to suggest another one - that would fit in a hard-science setting.

### Weapons are illegal

What if weaponry was really illegal and there was some kind of police enforcing the ban? You can't make weapons, you can't buy them, you can't sell them and you can't own them. If you know how to make them, you are either hired by the law enforcement or incarcerated.

This would make it extremely hard to get a hold of weapons.

On the other hand, mining equipment, towing equipment and even rocket exhausts make interesting improvised fighting equipment, though at a limited range...

5 solutions

1. Super electronic warfare - Renders all long range targeting mute
2. A much more effective CQC weapon and high rate armor - High yield slow moving torpedoes, heavy Particle Blasters, Auto cannons. Why fire your effective weapon out of their effective range?
3. A wide asteroid field - you can't simply target at long range in this fied
4. Sociology-Political-military doctrine - live long enough and play politics long enough in 2 or more sides you'll achieve it
5. Socio-Cultural effect - developed long enough you'll probably see boarding action as a time proven method of battle

I would like to add a variation of Erik's excellent answer, in case you found the science there just a bit too hand-wavey: The solution is White Hole Shield techonolgy.

In short, you generate a hollow white hole around your fleet which, being the opposite of a black hole, deflects absolutely everything. Guaranteed to be an impenetrable defense against any weapon operating in 3D space. However, It does come with some significant downsides.

After development, as with many high-end technologies, it was first adopted by the military. The first warships equipped with White Hole Shield technology were neigh unbeatable, and soon just about every vessle that didn't have it's own shield would be travelling inside a convoy with a generator ship. It also didn't take long for the knowledge about this shield to spread throughout the observable universe, and so any enemy you'd fight would have the same impenetrable shield. This is where the fun starts.

One big downside with this kind of shield is that while you can't be attacked by anything from outside, you also can't really do much from within your shield. The hollow white hole deflects both ways. A white hole distorts space in such a way that you would need more than an infinite amount of energy to get to its border, so anything heading its way will just "fall" back out of the distorted space. Anything will, even friendly units, even light and other radio waves. You're inside a bubble of unreachable space. By the same virtue, you can't reach the outside either, you can't even see the outside (it'll look like you're inside a big mirror), the enemy can't see you either, but it's trivial to detect the presence of a white hole because of its excellent reflective properties.

You can only battle your enemies by disarming your shield (temporarily?), and they would have to disarm their shield to battle you. Like in medival times, impenetrable strongholds could simply be starved to death, and some point they'd have to come out and fight you on equal terms. You also can't just leave the shield on until the support gets there (which is at best lightyears away) or drive with the shield on until you get home (your enemy with their white hole is distorting the space you fly through, and you can't see the stars outside your shield for course correction).

So the tacticians of just about every military operate as follows:

1. Get close
2. Disable shields
3. Send out the cavalry

You can shield your cavarly with smaller shields (less distortion, to get closer) so they don't get shot down. You can shield your missiles, but they'll have to deactivate before impact or they'll deflect themselves off of the hull, and since you can't communicate with anything inside the shield, you have to set the timer in advance and do it perfectly or it'll get shot down. What's worse, is that even if you time them they can still be deflected mid-flight. Shielded missiles are only useful in very specific situations, if your government is being lobbied to buy shielded missiles, call your representative and have them vote against the proposal. You can trap an enemy inside your shield if you can handle generating at that size, but be very careful because anything unguided flying inside your shield will keep bouncing around until it crashes into something. On a related note, never generate a shield over half the enemy's ship or any other matter. Sure, it'll get ripped in half, but then you'll have half a ship being hurled at your face at great speed.

Pros:

• Impenetrable.
• Can get close to enemy.
• Everything except the shield generation itself based on the HARD SCIENCE of general relativity. [1]
• Doesn't need to be artificially expensive.
• As big or as small as you need it to be, given that you can fit a generator within that space and can power it for the duration you need it to.
• Compatible with most hyperspace drives, just activate the hyperspace drive before the shield. [2]

Cons:

• No vision, no comms outside shield. (can't leave it on permanently)
• No impact outside shield
• Have to get close to enemy.
• Easy to detect.
• Your ship tends to get quite hot inside the shield as all radiation is bounced back and reabsorbed.
• Generator must be inside the shield because of hand-waving.
• No defence against projectiles from the higher dimensions.
• NEVER EVER cross two stream- I mean shields. It would be bad. [3]

[1] Whether or not general relativity allows for white holes or hollow white holes is left as an excersise to the reader.

[2] The basic functionality of hyperspace flight, also being based on general relativity, is completely compatible with White Hole Shield technology. However, depending on your hyperspace drive operates, you might encounter compatibility issues such as not being able to change direction within the hyperspace, not being able to stop, or your hyperspace collapsing prematurely. Generally, disabling your shield is enough to counter these issues. Hyperspace distortions in the forward direction will weaken the shield and actually be made partially see-through, depending on how strong the drive is! Most hyperspace drives use double-ended hyperspace and thus will have this side-effect. The hyperspace distortions at your rear end have little meaningful effects.

[3] The theoretical physicists involved have widely varying theories on what would happen might the shields actually cross, all the theories end in catastrophy, but this has never been tested.