We all know and presumably love enormous space battles with vast battleships doing minimal damage to each other for hours before being blown up by a single fighter.

On Earth battleships became big white elephants with high cost and minimal use, vulnerable to every submarine, aircraft carrier, and missile boat in the sea. The era of battleships on Earth is over.

However in space, there's no stealth, so no submarines. "Range" has an entirely different meaning. A simple slug or contact explosive shell has "unlimited" range, where a fighter still has a strictly limited flight time. The concept of "over the horizon" is totally non-existent.

So in the great trade off between drone carriers, missile boats, and battleships:

Was the era of space battleships over before it even began?

Or can they still be justified in light of the limitations on the factors that made them redundant on Earth.

Assume no great deviation from current understanding of physics apart from a high volume black box non-reaction handwavium drive to power the whole thing. Defined as too big to put it in a fighter, and not directly usable as a weapon itself. I'll also permit artificial gravity to reduce the distractions from the core problem.

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    $\begingroup$ Big ships are very powerful and have great endurance. Small ships are cheaper and one can make many more of them to cover more space. There is a trade-off. Where the balance will sit depends on the specific conditions, and mostly depends on the story you want to tell. But in the unfortunate eventuality that space fleets will be needed, there will certainly be big powerful long range very expensive ships and small cheap ships. As today we have both conventional diesel electric submarines and humongous nuclear submarines. $\endgroup$
    – AlexP
    Commented Aug 21, 2019 at 9:07
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    $\begingroup$ Just a minor point but "However in space, there's no stealth" doesn't seem really true to me. Space is HUGE and anything can come from any direction. You can look everywhere but things can just do their best to blend in with the background. $\endgroup$
    – Marie
    Commented Aug 21, 2019 at 17:29
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    $\begingroup$ @Separatrix The problem with your answer is that you seem to imagine space battles like in Star Wars or Battlestar Galactica (1978). The less like them, the more realistic your space battles will be. Airplanes became important in naval warfare because they flew in a different environment than ships sailed in. there is only one medium in space. There is no horizon in space to limit detection. So space fleets will fight at longer and longer ranges like sea fleets did, but with none of the limiting factors that led to disuse of battleships on Earth. $\endgroup$ Commented Aug 21, 2019 at 17:30
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    $\begingroup$ @Marie Blending in with the background is actually very hard. One of the primary engineering challenges of spacecraft design even today is radiating waste heat so your crew doesn't cook. People talk about space being cold, but vacuum doesn't conduct heat away like cold air does, so spacecraft are always VERY hot by comparison to the background, which makes them easy to spot if you've got good telescopes and a good computer to filter out everything that's a known heat source (e.g. stars etc). $\endgroup$ Commented Aug 21, 2019 at 18:17
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    $\begingroup$ This query has done no worldbuilding at all. Battleships with regard to which factions? With what weapons capabilities? Over what range of space? With what sort of technology? Against what opposition? With what operational limits? Where is your world these battleships have become obsolete in? Anything at all? The non-reaction drive that can't fit in a small craft automatically creates an advantage, BTW. $\endgroup$
    – Vogon Poet
    Commented Mar 4, 2022 at 5:46

19 Answers 19


high volume black box non-reaction handwavium drive to power the whole thing.

You actually solve your own problem right here.

The biggest reason that a space battleship makes no sense under current or proposed technological limitations is because of the demands of reaction drives. More Mass to move = more reaction mass to move it. It's a tyrannical equation that, as long as it is the primary constraint to propulsion in space, will ensure that the MOST critical design element of any spacecraft is making it as light as possible. This means no armor, which means no space battleship.


If you have a reactionless drive, that changes everything. Now more mass = more POWER to move it, and that doesn't necessarily add mass. Modern Aircraft Carriers benefit from being SO huge and expensive already just to do what they need to do, that adding a nuclear reactor to run the whole thing becomes not only feasible, but very beneficial from a cost/benefit perspective.

Your Handwavium powered spacecraft would have the same benefit. The larger your ship is, the more it can benefit from economies of scale. You can afford to put a lot more mass into your environmental recycling so your ship can go further and stay out longer. You can grow your own food onboard. You can completely protect your crew from the hazards of radiation. You can actually afford to put a thick, tough shell around the outside of your ship to protect it from environmental hazards like micrometeorites as well as smaller kinetic impact weapons, and you can afford to put a LOT of point defense on it to stop bigger stuff.

And, in true battleship style, the bigger your ship is, the bigger your gun can be. A Mass Driver is a pretty optimal weapon for engaging anything that can't move under its own power, and for many things that can as long as you can throw a big enough projectile fast enough.

Battleship on Battleship combat under these conditions would be a dance of who can get a better target solution on who sooner, and start putting Significant Holes in the other ship. I don't really think it's feasible to design armor that can STOP projectiles with the kind of energy that mass drivers are capable of, so instead you want to design your ships such that high velocity kinetic rounds go right through and deposit as little energy as possible on their way. This means elaborate compartmentalization and redundancy to ensure that your ship can retain as much combat effectiveness as possible even after it's had a bunch of holes poked in it.

The Expanse does a pretty good job with this, actually.

  • $\begingroup$ I accept your argument for long range vessels where resources and supply chain are important, but I'm not convinced when it comes to fleet engagements. Either a carrier or a missile boat will get a better target lock faster, which you've said is a critical factor, and will be able to deploy weapons more effectively than a ship dependent on a small number of large guns for the bulk of its damage output. $\endgroup$
    – Separatrix
    Commented Aug 21, 2019 at 14:33
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    $\begingroup$ I'm not sure why either of those things would be true. What kind of ship it is has nothing to do with getting target lock. Most importantly, a mass driver projectile is going to be able to cover the distance between two ships MUCH more quickly than a fighter or a missile, and is much more difficult to intercept with point defenses once it shows up. $\endgroup$ Commented Aug 21, 2019 at 14:48
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    $\begingroup$ There's no reason you'd need to go with a spinal-mounted mass driver for ship-to-ship combat. You can turret those guys just like Space Battleship Yamato. Save your fixed-axis Wave Motion Gun for planetary bombardments or space installations that can't move. $\endgroup$ Commented Aug 21, 2019 at 15:05
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    $\begingroup$ If you're firing at targets far enough away (as is the case in realistic space warfare) then the time it takes to aim your weaponry should be negligible, thus turning the whole ship should not be a major issue. The only concern would be exposed profile, but aiming at your target probably exposes the optimal profile anyway. $\endgroup$
    – Muuski
    Commented Aug 21, 2019 at 22:51
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    $\begingroup$ With the kind of handwavium drives described, there's no need to build any spaceships ever at all. Just move your homeworld solar system, complete with its star and a hundred colonies you've moved to it previously, to wherever you want to dominate. Win, go on. $\endgroup$
    – Therac
    Commented Aug 27, 2019 at 20:18

There are many parameters to take into consideration.

Some historical evolution

To make it really simple, the de facto standards of naval battles of the 18th and 19th Century died out because weapons became far too effective and the costs of such large-scaled battle was too huge. The WWI's Battle of Jutland is often considered the last of its kind.

A jump in time to WWII which saw somewhat the end of the large battle ships (Bismarck). The reason was again that even with large costs, the defense were not effective enough against new and/or specialised weapons (submarines, planes, torpedos, etc.).

Fleets nowadays consists in smaller specialised ships (e.g. anti-mines) and tactical ships (submarines, aircraft carriers). And seldom considering an actual sea battle. Supporting weapons (planes/missiles) would actually finish it before it even begins.

Defending your space ships

We see that the issue with seafaring ships and battles is the effectiveness (what they do in comparison for their price) is too low due to other types of weapons/ships. Simply put, they are not resistant enough.

To get space battles à la Star Wars, you'll need to make sure you equip your ships with solid defenses. So they should be able to get a missile or a laser without blowing up immediately. Back in the 18th Century, a ship often needed several hits to be out. And even that often meant that the ship was not sunk. Currently a torpedo, a mine or a missile could well bring the whole ship down.

How do you defend effectively? Well that's an interesting question.

  • Heavy armours aren't a practical solution, because we see already on Earth ships that they have limitation. And for the space faring, weight is a very important issue.
  • Most Sci-Fi tropes using some kind of defending force fields. You need that. But something that can block missile, lasers, and just the small piece of junk sent to you is going to be very challenging. Especially if you don't want to be moved around off your course!

Space fleets

Seeing the current situation on Earth and extrapolating, it is likely that you would have specialised fighting ships (thanks to your handwavium) (X-Wings/Tie) and then ships carriers. Those would be surrounded by a fleet of cheaper and first line defense ships. You should not let any attacker get close to your carrier.

But then, considering the price of such a fleet and material requirement, your handwavium should allow us to go mine the other star systems ;-)

  • $\begingroup$ Heavy armor as a limitation in naval battleships is primarily due to attackers being able to bypass it by traveling through another medium; the air for planes and missiles, underwater for submarines. This doesn't apply in outer space; you can armor all around except wherever your engine exhaust is. It also means that space fighters, unlike jet fighters, possess no special maneuverability advantage whatsoever and are thus impractical. $\endgroup$
    – Joe
    Commented Oct 4, 2019 at 15:00

Here on earth, battleships were built when guns became so big and their range so long that a smaller ship could not carry such weapons, let alone use them. Their era ended when their opponents could counter the threat of the big guns on the big ship, and when much smaller platforms, like submarines and aircraft, could pack enough punch to threaten the big ships.

Apart from being a platform for very large weapons, a battleship is also a small city, providing all kinds of living facility for a large crew. That means that a battleship can go on much longer missions than a torpedo boat or similar.

Combined, the large weaponry and the ability to stay in the target zone for extended periods enables a battleship to besiege a target, like a port or similar.

What does that mean for sour setup? For a start, space is big, so space travel takes time, which in turn means you need living space and facilities to keep your crew alive and reasonably happy. We already saw that a battleship can provide for those needs. The big guns should be a no-brainer: just install whatever the arsenal of your mind can think up, especially when your weapons of choice are suitable for laying waste to ships and installations alike.

Now to the downsides. A big ship is a big target. It typically lacks agility, and thus the ability to dodge attacks. So you need armor that can take a few hits. You will possibly want a lot of defensive weapon systems to counter attacks by fighters and missiles, and you might want to hybridize your battleship with a carrier so you can bring a few fighters yourself.

Still, your battleship will be a specialized weapon platform, and while being able to lay waste to a lot of infrastructure, and being able to take some beating, they won't be invincible, and there will be military vessels of much smaller size for other roles.

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    $\begingroup$ "It typically lacks agility, and thus the ability to dodge attacks." Perhaps not as large of an issue as you'd think: modern warships, no matter how fast and maneuverable, still aren't fast and agile enough to dodge modern weapons. $\endgroup$ Commented Aug 21, 2019 at 16:28

Well, since space battleships are not for actual space battles between fleets (fighters & destroyers and the other tin-crap are cheaper and better suited for this stuff), but for laying siege to planets/solar systems and for carrying all the important stuff for either capturing the planets - or simply laying waste to their surface - the era of space battleships is definitely not over.

Really, how should one of these tiny destroyers lay waste to a space-port? Or even destroy the Earth's defensive system of orbital stations? Can't do - but that's what battleships are for. Also, they make impressive command vessels.


One major design consideration for realistic space warships is the square-cube law. Every time you double the length of the ship, you increase its surface area by a factor of four, and its volume by a factor of eight. This has both advantages and disadvantages.

The most obvious benefit is that you could have armor that's twice as thick as the armor used by a smaller ship, but which takes up the same proportion of the larger ship's total mass. However, the major disadvantage I see is that you have less surface area, proportionally, with which to radiate waste heat. If the limiting factor of your warship design is disposal of waste heat (which, realistically, it probably is), then a ship with twice the length will only be able to afford to run reactors and engines which are four times more powerful than the smaller ship, despite being up to eight times the mass. This would make a ship with twice the length able to sustain only half the acceleration of the smaller ship. So from that standpoint, space battleships really would be better armored and slower than space corvettes.

Of course, this assumes the larger ship has the same shape as the smaller one, which it may not have. You can stretch the shape of the ship so that the larger ship ultimately has the same ratio of volume / surface area, or simply leave a greater proportion of the larger ship's volume empty (which I'm sure the crew would appreciate). This would abandon the pros and cons offered by the square / cube law; which I'm not sure would be the best idea, since a larger ship makes for a bigger target, and you've just given up your armor advantage.

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    $\begingroup$ I like this comment a lot. Many people do not recognize the severity of head dissipation and the square cube law. One thing i would add that the need to dissipate heat would mostly depend on the type and efficiency of the / a reactor. By using a smaller reactor and possibly say kinetic instead of "beam" weapons, a vessel would have to dissipate less heat. For example, outfit a battleship with only missile batteries instead of lasers and it would require far less reactor %. $\endgroup$
    – user431806
    Commented Aug 22, 2019 at 13:39

A couple points I don't see mentioned above and are worth remembering regarding naval Battleships:

  1. An asset doesn't need a high body count to prove its effectiveness. If your goal is power projection, a weapon that no one wants to pick a fight with is a supremely effective weapon indeed. "Supreme excellence consists of breaking the enemy without fighting." - Sun Tzu.
  2. It's not just about cost effectiveness. Battleships remained a major component of Naval warfare into the 1990's, contributing heavily to the Coalition victory during the First Gulf War. However, around the same time, smart munitions were becoming more and more viable; this allowed smaller ships to match and exceed the stand-off potential of the Battleship, rendering the larger vessels redundant, its job superseded by every other ship in the Navy.

So, in essence, battleships were rendered redundant because gravity and air resistance made projectile weapons less effective at long-range when compared to modern guided missiles.

Addendum: To help illustrate my above point, the 16-inch guns on an Iowa-class Battleship had an effective range of 21 nautical miles (39km) while a Harpoon anti-ship missile seems to be a rather short-range system at between 67-120 nmi (124-220km).

But this is all rendered moot in space where any object launched by a ship is likely to continue on until it rams into something so your limit isn't just the weapons' ranges. Instead, you have to consider the specific advantages and disadvantages of each weapon and their likely role in combat.

Guided missiles obviously have the ability to adjust their trajectory during flight, able to pursue a target and evade countermeasures until they are close enough to do whatever they are designed to do. However, guidance systems are relatively fragile; no matter how durable you make their systems, there will always to be a limit to how quickly a guided missile can accelerate, giving them a minimum effective range, wherein an enemy's countermeasure can intercept and kill them.

Projectile weapons are, of course, the opposite. They don't have the ability to adjust their trajectory, meaning if the enemy is far enough away, evasion is trivially easy. However, they have no need to worry about acceleration, meaning the only limit on how fast a projectile can be flying is the size of the gun: longer barrels - regardless of specific propulsion - offer exponential rather than linear acceleration, allowing for higher relativistic speeds..

Of course, that assumes that "Guns" in space would only refer to kinetic weapons which, due to potentially still slow projectile speeds, might prove to have limited effective range. However, if your setting instead relies on Directed Energy Weapons like Lasers and Particle Accelerators, a larger ship would likely carry a larger powerplant, itself feeding a larger weapon batteries.

  • $\begingroup$ You've picked up the purpose behind the question well, but does that same redundancy transfer into space where gravity and air resistance are no longer an issue? $\endgroup$
    – Separatrix
    Commented Mar 4, 2022 at 8:09
  • $\begingroup$ Obviously, without Gravity or Atmosphere to slow it down, a massive projectile would have infinite potential range. Mind you, "effective range" is a lot trickier to think about given that is heavily tied to how fast the projectile is going, with bigger guns potentially able to fire faster-moving projectiles. I've expanded my above post to include more in-depth thoughts on the matter. $\endgroup$
    – Kingfisher
    Commented Jun 27, 2023 at 3:23

Besides carrying big guns I think size isn’t everything even space. Reason:

  1. Small ships are build faster and don’t need an extensive crew if any at all
  2. Small ships will be better maneuverable and cost less energy to do so
  3. Even a small delivery system can potentially carry a devastating payload. It doesn’t necessarily require big guns but smart ammunition delivering enough energy to destroy the target.
  4. The destruction of one big ship is easier done than many you could have build from it as it might need just one hit.
  5. Engagement ranges are very large and detection ahead of time will be difficult. Even more with smaller vehicles, due to smaller radiative cross section. Using active means like radar on large distances I’d imagine to be physically impossible. A small vehicle could therefore sneak up closer than a big one and detect you earlier. Deliver faster and reduce reaction time.

That said there are reasons why big ships could be useful. But if it is about delivery I don’t think that those would perform to well at the frontlines.

So what you are looking for is most likely some sort of good mix of weapon systems and special purpose roles in your fleet.

  1. Carrier
  2. Logistic
  3. Recon (could be drones but the communication might give you away so they have to be autonomous)
  4. Destroyers
  5. Something between recon and destroyers
  • $\begingroup$ Now we use radars to measure distances to planets and asteroids. They are FAR away. Radar is a good thing for space battleships and can reach far. Thermoemission detection works even better. It is very hard to hide in space. $\endgroup$
    – ksbes
    Commented Aug 21, 2019 at 11:40
  • $\begingroup$ The radar signal decreases with inverse square of the distance. This means your returning pulse will greatly diminish with range and size. Planets and some asteroids are pretty big...ok I give you that. But how big does and object has to be to reflect enough so that it doesn’t go under in your signal? On top you might have some absorbent or diffusing material ...so it will be though. $\endgroup$ Commented Aug 21, 2019 at 11:47
  • $\begingroup$ Thermoemission is indeed a a problem. But I don’t think it’s impossible to hide that if you want to. You will have to find a way to store the heat and release it at later times. Proper insulation and acceleration at have to need basis will make you still hard to spot. $\endgroup$ Commented Aug 21, 2019 at 11:58
  • $\begingroup$ The point is that background of space object is effectevly nothing. It is not hard to detect even the lowest amounts of reflected signal. Planets and astroids are large but they are hunders of million kilometers away. It means if we can radar Mars, we can radar tennis ball from 2000 km. And termoemission: you also need to cool surface of your ship to -270C (and have thermosink up to thousands of degrees inside). Good luck with that! $\endgroup$
    – ksbes
    Commented Aug 21, 2019 at 12:04
  • $\begingroup$ 1) Ok sure enough the thermal radiation is still there ..but how will you make the difference between an stone and a space ship with just the signal ? 2) Mars is comparable big to a tennis ball. The cross section is what you get back and the cross section goes with r^2.... so we speak about quite a different signal strength. If you can detect let’s say objects with r=50m at 2000km that’s great but not enough for your space ship... $\endgroup$ Commented Aug 21, 2019 at 12:23

Space battleship has one great battle advantage: big mass. It allows:

  • use of more powerful guns - recoil is not that hard on structure, crew and course (they can even use ballast just to increase mass for that)
  • can sustain much more damage - it is no water to sink in. That means that a slug which evaporates fighter or cuts in half corvette would not destroy battleship. And even if battleship falls apart, some of this parts still would be able to fight (shoot at least)
  • huge inner volume for resources (longer range), ammo (can "oversit" smaller ship in barrage), some lesser crafts (universality)

This are great advantages, so battleship has its future (if fuel problem would be solved).

On Earth battleships became obsolete because they sink too ease. If not, they still would be the most powerful ships. There is even an idea of battleship with lots of anti-weapon systems (laser and not + powerful computer) which would make it invulnerable against rockets, bombs and high-ark shells of any kind (at least for some time). Those monsters would destroy carriers with there support ships at ease.


The Scale of Space makes battleships - or any warship - infeasible and unnecessary.

Space is really big - no matter how big you think it is, it is way bigger.

To traverse the vast distances involved you need to accelerate to unfathomable speeds, and stay at these speeds for unfathomable amounts of time. Even if you have an amazing ability to thrust with your drive, it does not reduce the incredible speeds that need to be attained to traverse such large distances.

A spaceship with guns on it makes no sense. A gun makes no sense. Firing a gun from a turret would be firing a small pellet only a little bit faster than your ship, which is already travelling at likely hundreds (if not thousands) of kilometres per second anyway.

At such astronomical speeds, collisions are more like high energy impacts with no defense. Materials at these speeds interact as if they were gases, they do not behave in collisions as solids - there is no 'armor'.

Even in LEO (low earth orbit), these make no sense, as interactions would be just the same. Not to mention interplanetary or interstellar distances, where distances are simply too large for any meaningful defense. A small asteroid or even a small ball, accelerated constantly over time, accumulates so much kinetic energy if it encounters a planet it could devastate it.

Therefore, I can see little tactical or strategic advantage to a ship with guns. Just accelerate small masses to great speeds.

  • $\begingroup$ This answer makes a lot of assumptions that I don't think are warranted, or supported. $\endgroup$ Commented Aug 21, 2019 at 15:38
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    $\begingroup$ "Accelerate small masses to great speeds" But to do that you would need a machine to cause that acceleration....what are those called again? Guns! That's right. Now those guns, they might need to move around the system to hold locations of strategic importance, it would be convenient if those guns were mounted on something that moves....what shall we call that thing that moves guns around I wonder? $\endgroup$
    – Muuski
    Commented Aug 21, 2019 at 15:57
  • $\begingroup$ Even if hypervelocity impacts mean that armor can't survive more than a single hit, it can still protect the ship underneath it by absorbing the impact. The armor is ablative rather than deflective. In order to get your small ball up to great speeds, you need to attach an engine to it, which effectively makes it a missile, and missiles can be detected and intercepted. Also, with modern technology, a 300 meter long railgun would be able to get a 20kg projectile up to about 12 km/s. The question isn't the speeds the ships are already at, but if they can change speeds fast enough to evade. $\endgroup$ Commented Aug 21, 2019 at 15:58
  • $\begingroup$ The salient point of this answer is realistic space travel. Requiring 'space battles' requires equally advanced species (very unlikely) in close enough proximity (extremely unlikely) and a resource or something to fight over (something so valuable it requires traveling for decades or centuries to retrieve.) From that perspective the basis of the question is ludicrous. However, since this is worldbuilding one can easily construct such a universe rendering all of those points moot - and still maintain the same underlying physics as this universe. $\endgroup$ Commented Aug 21, 2019 at 19:54
  • $\begingroup$ The point "Just accelerate small masses to great speeds." indeed lead to guns and if need to move a ship even if been just a gun platform drone. If race A found the rare resource a, and race B has not here it goes: Race A protects resource with 1000 ships out of fear of race B. But race B builds 1000 explorer ships and, eventually finds resource another a. Waste of resources for race A. If conflict arises, chances are A and B spent Terra tons of resources for fuel the war at a point where resource a become insignificant. $\endgroup$ Commented Oct 6, 2019 at 7:28

Considering "battleship" as "large armored weapons platform" then in a space war scenario there would be a sensible use for them: in orbit.

Battleships would be placed in orbit and stay there. They would offer a commanding position for attacking planet-bound structures. Really though, the battleships would defend against incoming rocks.

For a civilization capable of space flight, the best way of attacking a planet is to use its gravity well against it and throw things at it from a great distance. To counter these rocks you have to see them coming and you need to deflect them, before they enter your atmosphere. If you are above your atmosphere your vision is clearer and you can see them farther away. Your defensive fire will not be slowed by your own atmosphere. The bulk of your ship means recoil from your energetic defensive fire will not substantially move you out of your orbit.


It is predominantly a question of engine and weapon energy efficiency. Intense maneuvering would be out of the question for such a large ship. Its primary offense would be to launch projectiles that are fast enough and accurate enough to be difficult or impossible to dodge and that deliver sufficient energy to disable a target, and its primary defense would be to intercept, deflect or diffuse/defuse incoming projectiles, similar to the way a Phalanx gun works in naval combat by shooting down missiles (at close range in this case for maximal accuracy). As soon as its energy or projectile reserves are depleted, it's a sitting duck.

A moon base would probably actually be the ideal deployment scenario for such a ship, since stationary nuclear reactors fueled by mines, vast arrays of solar panels and geothermal energy could provide the energy to power the offensive/defensive weapons and would not require recoil compensation while in a planetary environment. A smaller moon with a landing pad, or possibly a geostationary tether would be ideal so as to limit the amount of energy required to take off and land or dock with the planet/moon. The greatest difficulties might be the storage of energy and the expense of takeoff/landing and of changing course. Nonetheless, given sufficient energy reserves for the tremendous length of a space voyage, it would make a formidable offensive weapon against ships. Subjugation of a sufficiently well-supplied and technologically advanced planet would at all points prove difficult, however, due to the resource and economy imbalance, and is not advised.

It would need to dock with or be in close proximity to an energy source regulalry to keep its armaments at full power, so its primary utility would probably be far more defensive than offensive. Being able to store, generate or harvest enough energy in the far reaches of space to make it an efficient offensive weapon is the primary bottleneck which is why super-energy reservoirs such as the "Tesseract" of Marvel fame are the stuff of science fiction.

So I think it's primarily answered by what size of ship or technology configuration would give you maximal energy efficiency.

Naval Phalanx gun


So in the great trade off between drone carriers, missile boats, and battleships:

Was the era of space battleships over before it even began?

Like written here it depends on your technology level, on your power generation and the propulsion technology.

If you don't have a reaction less drive there is no use of big ships like a battleship. You want to stay small so you need less fuel on board for moving the ship. Heck you don't even want humans on board because the need a huge and heavy infrastructure on board to survive and the longer the deployment the more weight you need (food, water or aquaponic areas or recycling stations).

So with a current level without reaction less drives there is also the constrain of the detection range. In naval warfare this is also a factor what is a laser defense system of use if I can detect the shell? Or if I detect it to late? This applies also to space. What use of a mass drive that can hit spot on on a distance of 10 light minutes? If it cannot detect a ship that is 1 light second away?

So these two points lead us to space battles with drones, where the command center is on a different astral body and gives general commands to the drones, like destroy that ship. For drones it is then interesting to have drone carriers, so these would be bigger, but still more like a skeleton where lot of drones can dock, like in Enders Game. But these carriers would stay behind the actual front to save them from harm. Now also a few command ships would be useful that support humans. Thes would also stay behind and just give commands. Should the battle be lost these ships have a huge interest to disappear quickly. For that it needs to be light not a lot of mass, let me just say E=mc². And then small so detection is harder. Look at the problems that are currently exiting to detect small drones at airports.

All in all I would say drone carrier would exist also command ships, but no large ones with big weapons like battleships, also manned missile boats are unlikly. If you know Stellaris you can have a look on the tech tree bigger ships are only unlocked with the next tier reactor or better propulsion tech.

So it depends on your tech level if it is higher the bigger ships get practical like the others explained.


See the Honor Harrington series by Weber. He actually goes through a several generation series of offence and defence weapons.

Miltary grade ships have accelerations of 400 to 700 Gs with smaller ships being more capable. Missiles have accelerations of 10-50 times that, but their 'impellers' burn out. But 3 minutes acceleration at 20,000Gs covers major distance.

It's almost impossible to actually hit a ship. Most missiles carry a nuclear pumped x-ray laser that does the damage.

In the initial novels, ships have missile tubes -- much like torpedo tubes on a sub. Volley of fire was fairly slow: A ship with 20 tubes could launch 20 missiles per salvo, with about a minute between. Innovative tactics was to launch the first flights with lower acceleration so they would all arrive on target together.

Counter missiles were the response, plus point defence energy weapons.

Later large ships would carry extra missiles attached to the surface of their ship. These could be nudged off, then started when they were clear. Had to be used quickly, as they were subject to damage from near misses.

The tech war is one of control -- how to guide thousands of missiles in a battle, (they are light minutes from the ship that launched them...) how to jam, how to keep from jamming, and counters -- burn through jamming, better point defence.

A ship could 'go dark' Turn off it's impeller (which also was it's defence screen) reduce IR signature, and be very very hard to find. (Consider trying to find a 1/4 km diameter rock at the distance of Saturn, if it's painted black.)

In Weber's books, battle is mostly maneuver sometimes for days, and the battle phase may be only 2-3 volleys of missiles some minutes apart. Battle at this scale, requires that you have a spread sheet with the speed, distance,time arrangements for an accelerating body. (The accelerations are so large, gravity can be ignored)

Weber doesn't really address the commerce raider -- light cruiser ships designed to interdict merchant vessels, with the attendant response of convoys. Nor does he address stealthed ships much.


Space is huge beyond meaningful logical comprehension. We know the numbers as good as a 1st class kid learns to count 1-10, as the kid can only imagine what is after 10, how far it goes and even what those symbols will later on help him with.

Within space points of interest are scarce within that volume and valuable resources even more scarce. Multiplied by the space itself though, there are ... countless! But engaging the volume of space plus the time that is essential to describe space time, how can conflict arise? War between different species, because as long as we speak for civil war of 1 species alone, this war will start and end at the home planet. If and when humans manage to create a new colony comparable to earth to population, then we instantly speak for different species. It is the vast space itself that defines that:

Example 1: A meteor strikes Mars and Mars is now habitable, a brand new and virgin Earth. We go there and after 200 years Mars is a second Earth. Somewhat in better condition due to higher respect to the environment. So far so good. We know have Earthians and Marsians, because people finally understood that only unity will get them further and make them happier. Now Earth miss resource A and Mars miss resource B, while Earth has plenty of B and Mars has plenty of A. Obviously they trade. Not rage war with battleships to gain orbital control and then rage war with land and atmosphere vehicles to finally seize the opposing planet. The cost is forbidding. You simply trade the resource. Even the cost of transfer will be notable, but, nevertheless, far cheaper that war. Ok, and now the hard part. Both Eartians and Marsians miss resource C. What they do? Most likely they do not know where it is. Even if one found it, the other will also found it. A finders-keepers logic will not help. Most likely they unite efforts, search the entire system for the resource and, when find it, organize their safe extraction and transfer, so both share it. Why? Because it is cheaper. It is so deadly cheaper that with the cost of a space war they would find 5 C resource sources, and other 5 of resources D, E and F that they will come to miss in the future after shortage of C and, the rest of the funds will go for FTL travel research. :)

Example 2: Two races meet at the edge of their exploration bubbles. We obviously talk for available star travel tech level, minimum. While stories rage war, intelligent approach is different: First comes trade agreement, then exchanging exploration data. Those 2 things alone can be as valuable for both as multiple times their annual growth. Because both will be available to trade their abundant resources for rare ones (for them when match) plus both will be able to extract resources they miss, located at other space because the others simply so not need. Not to mention combined efforts. Actually is not really different than the Earth-Mars story. And why should be?

Combat fleets now. What for? Attacking who? Your own kind at another colony? Or an unknown 'enemy'? There would be some prototype warships, with the best of tech on, but not at a large scale. Again, space itself, protects. If the 'others' attack you, you know about it years before it happens. You should have plenty of time to produce equal or more numerous combat fleet on defensive position at your point of interest, before enemy actually arrives and with less energy than the one spent by your enemy to sent the fleet.

So yes. There would be top tech combat ships, from fighters to battleships and carriers, orbital defense stations, planetary defenses and all that stuff, but i can hardly imagine conflict possible, unless some species are ... not exactly intelligent or been warlike by DNA. Hard to advance to tech that way though.


Battleships may return... but as a Battleship/Carrier Hybrid, which is not possible on naval ships. With Carriers, which replaced battle ships as the "Capital Ship" of any blue water Navy, the main weapons are the ability to park a working air force base off the shore of the target. The ships themselves have little in the way of fire power, most of which is defensive (and if you're down to manning the guns as the carrier's last line of defense, somebody royally screwed up). The Carriers based of the Russian carrier (which isn't a carrier but an Aviation Cruiser... and is distinctly to allow it to not count as a true carrier to avoid it being a capital ship, since cruisers aren't capital ships... look, naval terminology is weird and more structured around cheating naval treaties than anything scientific) does have offensive capabilities of a modern cruiser ship and the aviation capability of a modern carrier... but it's been noted that such a hybrid ship does a terrible job as a cruiser and a carrier (since you can't fire your weapons while launching and recovering planes.). The primary reason why carriers themselves are lightly armed is because bigger guns would interfere with it's true purpose of being a mobile landing strip for planes, since the runways are on the top deck and outside.

In space, this design won't work... the crews doing the flight prep for a carrier's fighter compliment need to breath and it would be more practical to build the ship around a hanger/internal runway that runs the length of the ship than to build a hanger deck below the runway deck, if only to not have all the hassle of those crews needing to don Space suits and run around outside of a ship in a battle where the enemy ship can fire down onto your flight deck from directly above you. With that in mind, the surface of the structure built around your main runway will offer a lot of space to mount guns that point in all directions. These "Battle Stars" thus can make the best of both worlds that can't be taken advantage of in blue water navies.


Really great question. I would reference the use of combat spheres in The Expanse. When ships come within certain distances of each other, there are different engagement possibilities:

Near = railgun, PDC's Medium = PDC's, Missiles Far = Missiles (Very Far = Planetary defence)

Essentially, the feasibility of space combat, specifically with "space battleships" is not usually well represented outside of hard sci-fi, and even then has a fairly bad rap.

In space, battleships would become different, but still fill the same role: They would probably hold mainly long-range missile systems (probably both impactors AND fissile explosives), and short range PDC-style defences to intercept closer, smaller, targets.

For engagement with other battleships, you would probably find that battleships fill a sort of ICBM-carrier role: railguns, relativistic impactors, etc., depending on your tech-level.

(Of course this is just my best guess, and I can't really reference anything here. This may be so far off the target that future people will laugh at me!) In conclusion: They are feasible, but the distance over which a battle would take place makes them far removed from the relatively close quarters we're used to on Earth.

Hope this helps.

I'm new here so feel free to give plenty of feedback, I love it when I get constructive correction!


They are not feasible

Here is (one reason) why

One Aspect I did not see mentioned here, and is often overlooked in science fiction:

In space, there is basically no reason not to use nukes. Space is so huge that radioactive contamination is not an issue, unless beeing close to a planet.

So expect all ships to carry weapons powerfull enough to kill any other ship, regardless of size, in a single hit. It could be rockets with warheads or something like nuclear pumped lasers for higher tech levels. Or both.

With this in mind, you will want ships that are big enough to carry the propulsion systems and the state of the art weapon systems, but not much more.

One ship will be lost in one hit, but two ships will take two hits, so you really want as many ships als possible for your money.

Also I would expect that ships do not engage in battle directly, but launch a ton of warheads and counter warheads and counter counter warheads from as far away as possible and let them duke it out. If one gets through, thats the one that decides the battle.

Edit: All this is assuming we are speaking about ships that would somehow still be recognizable as "ships". This answer might not apply when we are talking about deathstar sized contraptions (see answer by JamieB).

  • $\begingroup$ It's overlooked because of the definition of battleship, i.e. a ship able to take repeated hits of whatever is being thrown at them. There's something I often remind people of in the history of weapons, it's a cycle, sometimes the weapon is dominant, sometimes the armour is dominant. Battleships came to be in an era when the armour was dominant in that environment, currently the weapons are dominant so nobody uses battleships. $\endgroup$
    – Separatrix
    Commented Jul 11, 2023 at 8:27
  • $\begingroup$ @Separatrix I'm unsure I understand your comment correctly. Do you mean, nukes are disregarded in sf because the author WANTS battleships and he can't have both? Or that battleships should just somehow withstand nukes, because of the definition? If the latter, my answer would be, battleships were still called battleships when they could be sunk by a single well placed torpedo or bomb. Also I don't see how you could EVER fit armor that would withstand a nuclear strike on a spaceship within the limitations of the question (no handwavium other then the propulsion) $\endgroup$
    – LazyLizard
    Commented Jul 12, 2023 at 9:39
  • $\begingroup$ The battleships in use fell out of use fairly rapidly (by naval standards) when they could be sunk so easily, they came from an era before easy access to air power and were largely made redudant by it. That's what I mean by armour and weapons going in cycles, when the first battleships were built they could take the hits, they went out of use because they weren't cost effective against newer weapons. As I understand it, your answer is "no, they were never viable", but you're fencing around it, perhaps out of the same nostalgia that keeps them as such a staple in SciFi $\endgroup$
    – Separatrix
    Commented Jul 12, 2023 at 10:10
  • $\begingroup$ I edited my answer to make the conclusion clear that they are infeasable. I don't quite agree on the "cycles" though, since (naval) battleships once obsolete never came back in real live (and I dont expect them to do that in space). $\endgroup$
    – LazyLizard
    Commented Jul 12, 2023 at 16:37
  • $\begingroup$ This doesn't address the application of beam weapons which would expand the maximum range far beyond the range of missiles. I don't believe space warfare would be fought solely with missiles. $\endgroup$
    – BMF
    Commented Jul 12, 2023 at 17:10

Battleships in space may be more viable than on Earth.

In space range is more or less infinite, this means that the winner of a fight is likely the person who detects the enemy first and completes their targeting calculations first. Having a larger ship could mean more sophisticated equipment for handling these operations.

There is nothing to counter inertia in space, this means unlike here on Earth where you can count on the air or the water to reduce act against your inertia, in space if you wanted to adjust your course to make a left turn you would have to reverse thrust to slow down your forward momentum, apply thrust the right to change course and then apply thrust to adjust your rotational facing. This is a prohibitive amount of fuel to be using, simply put evasive abilities would not be possible.

This all works in your favor, if you can detect an enemy ship and target them first, they won't be able to evade and all you need now is a powerful enough weapon to destroy them.

  • $\begingroup$ You don't need to slow down before making evasive maneuvers, or change the orientation of the ship either (unless, for some reason I can't fathom, the ship only has thrusters/drive for rotation and forward/reverse movements, not lateral movements). Instead, you only have to get the ship moving along the X and or Y axis (if the incoming projectile's path is considered to be the Z axis) enough to move it off the Z axis before the projectile arrives, regardless of any other ship motion in any direction. Should be possible with a (relatively) small thrust in any X or Y axis direction. $\endgroup$
    – Harthag
    Commented Aug 27, 2019 at 17:31

Think Bigger

One thing I think still missing in the answers above is just how big a "battleship" can be, especially with your "high volume black box non-reaction handwavium drive to power the whole thing" stipulation.

We are mostly thinking of ships, with a battleship being mostly the size of an earth battleship. And some of the answers point out the obvious flaws there of having a ship that could get hit with rail guns, nukes, etc, that pretty much blows right through your hull regardless of armor.

Unless your battleship was bigger. Way bigger. Like 1000km diameter. Why not? Your armor is 250 kilometers thick. I recently read a book series where the characters went through what seemed like a fairly plausible scenario of sourcing material from asteroids, smelting them in space using giant mirror arrays to focus solar energy, and turning them into giant hollow iron balls that you can fly entire fleets into. In one scene, they park one in front of a jump gate just to watch enemy ships splat into it. Nukes? It's like nuking the moon. It's not invulnerable but you have raised the bar to where any alien gun that doesn't fire a literal planet-killer cannot kill your battleship because your battleship is pretty much a small planet in mass. While the aliens are trying to glass one side of your giant-ball-battleship, your missile launchers on the other side are still churning out missiles.

(As I recall, they also used the solar mirror arrays to bring in the enormous amount of power required to energize the "black box non-reaction handwavium drive" to move the things. They didn't move all that well, but they did move. The aliens spent a lot of time being aghast that humans would think to build such a thing, and using their own stolen drive technology to make it work. They simply did not have weapons capable of breaking what is basically an iron moon. Other answers mention attacks at relativistic speeds but even that doesn't invalidate the use case, since a destroyed battleship at this scale is still a navigational hazard and a potential planet killer that only something with a similar sized drive has a chance of stopping. Here it comes at your home world! Good luck everyone!)

  • $\begingroup$ Bigger is getting onto the right lines, battleships are huge, they're expensive (though even the biggest were smaller and cheaper than today's big carriers) but by their definition they have to be big enough to take multiple hits from any weapons in use, as the weapons become bigger so do the battleships, but that also makes them bigger targets and easier to hit. Hence the question, are they already impractical and fundamentally obsolete before you even start building them. $\endgroup$
    – Separatrix
    Commented Jul 11, 2023 at 8:34
  • $\begingroup$ This would probably work, if you can build it and make it move.. however its maybe a bit of a stretch to still call it a "ship" ;) More like deathstar class. $\endgroup$
    – LazyLizard
    Commented Jul 12, 2023 at 10:04

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