We have two opposing forces: the Democrats and the Imperialists.

Each one can field an armada of ships numbering millions in their fleets, supported by trillions- to a quadrillion person strong super supply lines just to support the war effort, both in space and land. Heck, they even have mobile fortress worlds (Planetoids) as their fleet headquarters.

You, an aspiring young noble from the Imperial faction, want to be in command of a fleet of these mighty warships and lay waste to their planets. However, your enemies also have mighty warships and want to lay waste to your planets.

With your resources, manufacturing capability and support capability, your fleet is capped at 1350 ships. With this pitiful amount, you won't get anywhere against the enemy's millions stronger individual fleets.

Neither the Democrats nor the Imperialists have any knowledge of carrier doctrines. Doctrines that you discovered from the ancient libraries of Earth... You have continued developing this idea and technology further. Bombers and fighter bombers will be unmanned and have active cloaking technology to ensure you deliver your bombs and get out relatively unscathed.

However, you don't have any idea what kind of bomb would ensure maximum damage while ensuring that you don't suffer any consequences.

You'll be bombing the following types of targets. Note that the armor will be as strong as diamond but twice denser than lead. They don't have energy shielding. "Shields are for cowards," so they say.

All ships are big guns except corvettes. They don't have AA as they didn't know that space shuttles can be used to bomb them

  • Super Dreadnoughts (28 km long, 14 km wide, 8 km depth) 14 meters of armor
  • Dreadnoughts (17 km long 6 km width 4km depth) 10 meters of armor
  • Super battleships (14 km long 7 km width 3km depth) 8 meters of armor
  • Battleships (12 km long 5km width 3km depth) 7 meters of armor
  • Capital cruisers (10 km long 3.5km width 2.5km depth) 6 meters of armor
  • Heavy Cruisers (7 km long 4km width 2km depth) 4 meters of armor
  • Cruiser (5 km long 2.5km width, 900m depth) 2 meters of armor

Anything below 5 km is too little for your taste and conventional anti ship missiles launched from several hundred bombers can kill them.

The question is: what kind of bomb can you use against these capitals ships to take them down with the least amount of bombs?

Your 1350 space ships can support 25,000 bombers at any moment. 150 of those ships are 5 km long carriers holding 170 bombers each. A self-evolving AI is in command of the bomber wings from the carrier. Command and control is taken care of with FTL Communication arrays onboard all bombers. The covert communication array is only good within 5 light years away so the carrier won't be too far from the bombers.

Deep Space Bomber specifications

What you deep space bomber really is

Length: 64 metres (210 ft)

Width:75 metres (246 ft)

Height/depth: 12.9 metres (42.3 ft)

Engine unit(s):Twin fusion reactors

Hull: Titanium alloy


Covert Warp Drive

Stealth coating

Active Cloaking

FTL Covert/Standard Communications array

I need a bomb(Theoretical or proven) that can vaporize/destroy capital ships shielded or w.out shield with least possible amount of bombs.

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    $\begingroup$ Strong as diamond? Which can be easily cleaved? $\endgroup$
    – L.Dutch
    Commented Jun 30, 2017 at 4:47
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    $\begingroup$ What are the width and the height of all these targets? Why wouldn't a conventional kinetic bullet be sufficient to wreck them? $\endgroup$
    – L.Dutch
    Commented Jun 30, 2017 at 5:17
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    $\begingroup$ build a relativistic kill vehicle and blow it up before impact, creating a rain of a million pebbles travelling at 0.9c. nothing will evade or withstand that. It's also boring. $\endgroup$
    – Burki
    Commented Jun 30, 2017 at 7:05
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    $\begingroup$ I fail to see the advantage of using drones that return (as carriers) compared to just throw away vehicles. With no pilot on board and the obvious efficiency savings of a one way vehicle - there is no sense at all in using a standard bomber approach compared to kamikaze drones. $\endgroup$
    – TomTom
    Commented Jun 30, 2017 at 8:03
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    $\begingroup$ A small bomb will do, as long as you can get a fighter craft with an expert pilot who has mystical assistance to close to point-blank range and then fire the bomb down an unshielded exhaust port into the ship's main reactor. $\endgroup$
    – Mike Scott
    Commented Jun 30, 2017 at 15:17

15 Answers 15


TL;DR: Singularity Bomb

Honorable Mentions: The Little Doctor & Warp Bomb


I (the noble) have:

  1. 1350 spaceships (total).
  2. 150 5km carriers
  3. 170 bombers with self-evolving AI
  4. Covert FTL communication (How?) with a 5 LY broadcast range.
  5. Active cloaking technology.
  6. Covert Warp Drive

And I am expected to go up against

  1. Armadas numbering in the millions
  2. Supported by Trillions to Quadrillions of support personell
  3. Super Supply lines
  4. Mobile Planetoid Fortress Worlds
  5. With armor as hard as Diamond, but twice as dense as lead.
  6. They do not have energy shielding.


Why don't we begin with modern/theoretical science that we may discover within the

ancient libraries of earth

Soviet RDS-220 (Tsar Bomba, Ivan, Vanya)

Predicted maximum yield: 100 PetaJoules (1E17J)


Predicted maximum yield: 1.8E14 Joules per gram.

Hmm. We have AI, warp, cloaking, and FTL Technolgy. Furthermore, we can construct ships up to 28km long and transform planetoids (Dwarf planets) into ships. Mind you, planetoids can go up to a diameters up to 2372km (pluto) or (if OP meant asteroids) 975km (Ceres). In that case, I (the noble) have the technology to construct particle accelerators that would dwarf CERN's LHC on the ancient earth. Furthermore, CERN had already successfully trapped antimatter in those ancient times12 and was nearly detonated 3! Oh, and best of all, that ancient machine was not very efficient at generating antimatter; but, I can build it BIGGER and BETTER with our technology. Thus, it shouldn't be too difficult to produce 1 kilogram of antimatter, let alone 10kg - 1Mg. In order, they'd have an effective yield of:

1  kg: 1.8E17 J
10 kg: 1.8E18 J
1  Mg: 1.8E20 J

Eeek. That seems to be the limit of what actually generated in those ancient times. But times has changed. Perhaps the imperium and democrats regularly generate and use antimatter, but in missile form.


Let's move forward to what has been proposed in science fiction! I'll use this list for simplicity.

Akira's Orbital Laser (6.3E16J)

No Energy shields? Satellite based orbital laser? Sounds promising; but, we're looking for BOMBS not awesome repeatable weapons we can attack to a cloaked fighter. Or are we?

Photon Torpedoes (2.7E17J)

Really just a high-tech antimatter torpedo.

Illudium Q-36 Explosive Space Modulator (2.2E32 J)

Created by Marvin The Martian of the infamous ancient Looney Tunes.

Aperture Science Handheld Portal Device (1.78E48 J)

As a physicist and developer, I have no clue how they calculated this one. Nevertheless, the principle is sound: Wormholes/portals. Create a bomb that creates a portal upon impact. Always ensure that portal is connected to something such as ... a star and the temperatures will strip away the ship. Hook up the portal to a counterpart orbiting a black hole... and you'll wipe out the entire fleet.

The Little Doctor (9.8E58 J)

Ah, The Little Doctor from Ender's Game. Upon impact it causes a chain reaction that rips apart molecular bonds, spreading to all nearby matter. A single one of these may destroy fleets or planets.

Notable Mentions

Singularity Bomb

A popular scifi and high-scifi trope. Harness the power of a singularity (colloquially; black hole) into a weapon. Best example I can recall would be the Red Matter from Star Trek which annihilated a planet. Speaking more generally though, such a weapon, when detonated, would create a singularity. Immediately everything around it will be subjected to gravitational shearing and strength powerful enough to rip apart not only stars but neutron stars as well. Mind you, neutron stars have a density on the order of 1E17 kg/m^3 compared to the Imperium's and Democrat's 2.3E3 kg/m^3 armor. Suffice it to say that a single one of these will undoubtedly annihilate an entire fleet.

Effectiveness: 1:1,000,000+

Oh. And I forgot to mention the obscene time dilation, and the pillar of light that would be left in your awesome wake. Who would dare to challenge thee?

Warp Bomb

You have warp drives. They expand and contract space to move your vessels across vast distances without accelerating them. More importantly, if your (my?) engineers were to construct a bomb that uses the same principles to chaotically warp space within a region around the bomb. This will generate shearing effects that rapidly expands and contracts space asymmetrically. Since spatial curvature produces the gravitational force and rapidly fluctuating spatial curvature generates gravitational waves it follows that this would create a rapidly fluctuating gravitational field that may be powerful enough to shear matter. Given it's gravitational in nature, no armor can resist or dilute the effect, only astronomical distances. Furthermore, given the strengths of your warp drives, and the intent for this weaponized use, we may easily leverage warp-physics to make the bomb more powerful than warp drives; after all, we don't care if it's unstable, in fact we'd prefer it that way. This gaurantees that it may destroy the target; but, even if we use unstable warp drives powerful enough to move planetoids (ignoring space and weight limits on our bombers), it's not enough to wipe out fleets of millions.


The most powerful of these are The Little Doctor, The Singularity Bomb, and the Warp Bomb. The first two are capable of wiping out entire fleets whereas the last is guaranteed to eliminate capital ships. In my opinion I believe the Singularity Bomb to be the most effective. It causes the most destruction (wiping out entire fleets and/or planetoids) while also being the most plausible in your universe. I say this because I've studied Alcubierre Warp Drives. Generating a warp bubble requires obscene amounts of matter and exotic matter (1E64 kg) to generate the field. Recent publications have theoretical shown that the this limit can be reduced dramatically; but, the warp speed is also reduced abysmally as well. Given your universe, I suspect either civilization is capable of working with a comparably obscene amount of matter.

Answer: Singularity Bomb.

  • 1
    $\begingroup$ For that easy to understand explanation i'll give you +1! and the answer to my question! thanks! $\endgroup$ Commented Jul 1, 2017 at 2:05
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    $\begingroup$ There should be a mention of the Nova Bomb fearuted on Andromeda, which cancels out the gravity of a star causing it to instantly go supernova and destroy entire solar systems. $\endgroup$
    – Puppy
    Commented Jul 2, 2017 at 10:24
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    $\begingroup$ Note: a Singularity Bomb as described would realistically would not be feasible. A black hole is defined by its mass, charge, and spin. Only the mass is truly important when it comes to direct damage (spin would affect the paths of objects orbiting it, but not play a large part in damage, while charge would be able to do all sorts of weird stuff, but not very destructive). Mass must be conserved, so the singularity bomb must already have the required mass. Please also note that the radius of most black holes is relatively small, especially considering the size of the Democratic [CONTINUED] $\endgroup$
    – rytan451
    Commented Jul 2, 2017 at 11:13
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    $\begingroup$ Fleets. A regular black hole, one TEN TIMES more massive than the Sun, would only have a radius of 300km. This means that if a line of thirty super-dreadnoughts were to be hit in the middle with a singularity bomb, some of the ones on the sides would still escape. On the other hand, the Little Doctor from the Ender's Game universe is capable of easily destroying tightly-packed fleets and planets. $\endgroup$
    – rytan451
    Commented Jul 2, 2017 at 11:18
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    $\begingroup$ -1 Invoking "exotic matter" means this answer may as well be "magic". I can imagine an exotic particle that instantaneously transforms all baryonic matter within a kilolightyear into an equivalent mass of blancmange upon any scattering event. There's no particular reason to use any one magic bomb over any other, unless all you're really concerned with are the aesthetics of your explosion. If you are, may I suggest something that makes those ring-shaped shockwaves. They never go out of style. $\endgroup$
    – user31336
    Commented Apr 16, 2018 at 17:43

You need an Alcubierre Warp Missile.

Let's take the theoretical route for this. Theoretically, as the missile goes into warp, the Alcubierre drive creates a bubble around the missile. The missile warps the fabric of spacetime as it travels to its destination (which should be set right in front of the target). The space behind the ship expands, the space in front compresses. Sounds simple, right?

Except for the dangerous part; there are a ton of high energy particles shooting around in space. The farther the missile has to travel, the more of these particles it will encounter. These particles get stuck in the bubble around the missile, and when the missile finally arrives at its destination, the particles shoot out in a cone directly in front of your ship.

With enough travel time, you could destroy planets. The target also literally won't even see it coming since it's a faster than light missile.

Turns out the best bomb isn't even a bomb. It's a warp drive.

Reference: https://arxiv.org/abs/1202.5708

Here's a link to the actual pdf of the research paper.

  • 2
    $\begingroup$ Good see to your answer is supported with citations to the relevant research papers. One point I'm sure about: are you suggesting the Alcubierre warp gathers enough particles and energy to blast the target vessel on stopping or are you destroying the target with the warp itself? Plus one. $\endgroup$
    – a4android
    Commented Jun 30, 2017 at 2:40
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    $\begingroup$ This is an interesting idea. Another point worth considering is that an object under an Alcubierre could literally go straight through another one, effectively converting it to energy in the process. The tidal stresses on any matter entering the very-heavily warped space around the drive would be literally torn apart down to the level of subatomic particles. So if you're aiming at capital ship A, and ship B happens to be in the way at the time, this will go badly for both ships... $\endgroup$
    – Jules
    Commented Jun 30, 2017 at 10:33
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    $\begingroup$ I have something similar to this happening in a story I wrote years ago, and I'm grateful that actual physicists have looked at it and decided that what I just guessed would happen actually would happen (including, it seems, the overwhelming blueness of the event as I described it...). $\endgroup$
    – Jules
    Commented Jun 30, 2017 at 10:38
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    $\begingroup$ @micovillena The missile doesn't actually impact. The missile is actually just the smallest Alcubierre drive you can fit into a enclosed football containing enough fuel (and maybe a controller for targeting) to reach its target destination, which is right in front of the ship you're targeting. As the missile travels, it collects energy, and when it stops, all that energy is fired forwards in a (mostly) cone shape. Everything in that cone dies. A side effect of the missile is that you can penetrate anything, because you're literally warping space around the missile when it travels. $\endgroup$
    – Aify
    Commented Jun 30, 2017 at 13:19
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    $\begingroup$ @JBentley Nah, they got the fuel consumption down more recently. I think it's roughly the mass of Jupiter now. Admittedly, for a payload the size of a Voyager 1, but hey. $\endgroup$ Commented Jun 30, 2017 at 15:22

A block of Iron, or whatever element you like, heck, even wood

While this sounds like a rather stupid answer, i will still try to explain AND be short:

The correctness of this answer depends on how fast your Bombers + your Cruiser can go. I here assume that they can go very fast, since we have ftl communication. I also assume that they can accelerate to that speed quite fast.

Here´s how it works: Built some blocks of... lets say 1 Ton each. Depending on what material you use, you can save yourself some space. So osmium (has a higher density) should be better than wood (not saying that wood wouldnt work).

Now, depending on how many Tons your Bombers can carry (they are quite big), pack a few of those into your ships. I will just say they can take 5 here, you can calc your own amounts for your story.

Here come´s the trick:

You just accellerate your ships to the maximum speed they can go, probably something near the speed of light? Lets take 90% of it:

269.813.212 meters/second.

now lets calculate the kinetic energy, a ton of mass with that speed would have:

e= 1/2 * m * (v^2)

Kinetic energy: 1/2 * 1000kg * (269.813.212)^2 = 3.6399585e+19 J

so 1 of our Missiles would have an Energy of ~3.64e+19 Joule ( = 3.64*10^19) on one of our enemy ships. Now lets take this into perspective of what we earthly humans have achieved in terms of Energy (From wikipedia, Orders of Magnitude):

Tsar Bomba:

2.1×10^17 J

Estimated energy released by the eruption of the Indonesian volcano, Krakatoa, in 1883 :

8×10^17 J

So this simple block of mass is getting quite higher in terms of destruction force that our yet best bomb and should be fine to destroy one of those biggies.

Not confident enough? Double the mass, double the destruction power (note that this is only about going from 1 ton to 2 tons, todays bombs are quite bigger, so increased mass should really be no problem).

Speed is another thing. If you ships can go even faster, closer to the speed of light, the Energy increases in magnitude of 2. So double the speed, quadruple the energy. Relativity is becoming even more important here, the closer to the speed of light, the crazier the amount of energy goes, while reaching infinity at speed of light.

In addition

This is not my idea and it is not very new. Once you can reach high speed close to the speed of light, the most destructive forces are not Bombs or anything like that, mass itself becomes the killer of everything. There are even theories how to destroy whole planets, just buy putting a few tons of mass faar away from a planet, and let it "fall" into it, or accelerate it into it. The mass in addition with the speed becomes so powerfull, nothing comes close to those energies.

Now your ships just drop of some of these loads on your enemies, either one by one or calculated to hit at the same time, you can destroy whole fleets with just one of those loads (again, here depending on mass-capacity and speed of your bombers). So all in all, one of your 25.000 Bombers can take out lets say up to 5 Biggies. resulting in 125.000 Dead biggies per run. But my guess here is that your Bombers can carry a lot of more weight, but i didnt want to overestimate. So maybe give some comment about speed and mass they can carry, to make more accurate guesses.


Pack a ton of whatever into those ships, accellerate them towards your target, release the mass, return to base and get some more tons of whatever and repeat. Your enemies will think (the other ones, not the ones you hit) they got stuck in some kind space storm full of material while blowing up one after another, or all together)

  • $\begingroup$ This bombers cant accelerate by 90% speed of light but 20% at least if stealth is out of the picture... 5% if we are running full stealth this bombers can carry 5 tons in space and 1 ton in atmosphere flight $\endgroup$ Commented Jun 30, 2017 at 12:04
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    $\begingroup$ Use an entire squadron to tug an asteroid up to a relativistic velocity and unleash it. $\endgroup$
    – Burgi
    Commented Jun 30, 2017 at 14:30
  • $\begingroup$ Ok. So at the instant of releasing the 1 ton ballast your delivery ship is zeroing in towards the target at 0.9c. How much time are you giving your delivery vehicle to veer off the line of impact? Are they capable of the necessary acceleration? If not, you have a kamikaze mission. $\endgroup$ Commented Jun 30, 2017 at 18:47
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    $\begingroup$ @Jyrki then you forego the ton of material and just smash into the enemy. At those speeds it's probably simpler $\endgroup$
    – Patrice
    Commented Jun 30, 2017 at 19:03
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    $\begingroup$ In Iraq, the US used this principle when they wanted to destroy a structure with little or no collateral damage. Instead of using 500lbs of explosives, they dropped 500 lbs of GPS or laser guided concrete from high altitude. The kinetic energy of the impact was sufficient to destroy a structure without the collateral damage of an explosive. $\endgroup$
    – pojo-guy
    Commented Jul 1, 2017 at 4:02

We could build the bomb with current tech

There is no kill like overkill.

We want to reduce diamond-double-lead to gas or plasma. How much? How about all of it.

Take the largest ship. It has a surface of 28 km * 14 km * 8 km, times 15 meters.

That is (28 km * 14 km * 2 + 14 km*8 km * 2 + 8 km * 28 km * 2) * 15 m = 2.2E13 liters.

From http://www.materialsdesign.com/appnote/cohesive-energy-diamond we get that it takes about 18 eV to break one Carbon-Carbon bond in a diamond.

Each Carbon in a diamond has 4 bonds, so it is 36 eV per Carbon atom.

Lead is 11.34 g/cm3, so we have about 5.5E14 kg of armor here.

We'll assume C-12, so every 12 grams has 6E23 atoms.

5.5E14 / 12 * 6E23 * 36eV is 1.5E20 Joules.

1 megatonne is 4E15 Joules. So to reduce the biggest ship to its constituent atoms you need to apply about 40,000 megatonnes (40 gigatonnes).

The largest hydrogen bomb we have set off on Earth is about 50 megatonnes. So you just need something 1000 times more powerful.

Assuming we explode it near the target, something like 75% of the energy will be wasted (go the wrong way). That is just another factor of 4. Peanuts.

This just turns everything into free carbon atoms. Plasma would require also exciting the electrons to break free of the atom. From http://www.chembio.uoguelph.ca/educmat/atomdata/bindener/grp14num.htm we see that it is on the same order of magnitude (about 1/3?) as breaking the carbon-carbon bonds in diamond, so throw another factor of 2 at the nuke yield to finish the job.

How big a bomb?

So simply apply a 320 gigatonne thermonuclear warhead on your weapon, and set it for a proximity explosion. Most of the ship should be reduced to plasma.

There is no upper limit on the explosive power of a thermonuclear bomb. There where plans to build a 10 gigatonne bomb using current technology: https://in.rbth.com/opinion/2016/01/05/nuclear-overkill-the-quest-for-the-10-gigaton-bomb_556351 -- a space fairing civilization should have no problems exceeding that.

Note that these are ridiculous weapons, and you could probably succeed with smaller ones.

A smaller bomb (say, 100 times smaller) would just penetrate the hull locally instead of evaporating the entire craft. We could today, with a modest engineering effort, put together a 1 gigatonne bomb and (if delivered) cripple or destroy one of the largest ships.

You could also get fancy, like some kind of nuclear shaped-charge or penetrating round -- use a small nuke to knock a hole in the ship, then drop another nuke into that hole to cook the ship from the inside.

The fundamental problem here

Chemical bonds are weak compared to nuclear energy levels. As your ship is defended by chemical bonds, it has no real durability. The near parts of the ship would become highly energized radiation and deposit the energy further in. The ship's matter itself would become the blast wave.

The point I'm trying to make is that the ships you designed aren't that tough. The energy required to move Planetoids dwarfs the effort required to atomize these ships, making even the bombs I'm describing puny.

You are describing impressive chemical-era weapons in an atomic era.

Your ships, as impressive as they sound, are mild evolutions of someone carrying an volcanic-glass sword and wearing animal hides -- they are merely weapons based on electron bonds between atoms.

We are currently in the atomic era, chemical bonds are not an effective defence against atomic era weapons.

An interstellar civilization should have weapons that make our atomic and thermonuclear weapons look like toys, much like atomic bombs make obsidian swords look like toys.

The energy required to travel between stars, move planetoids, etc is large. Ships designed with chemistry-based armor or weapons are not ships of war in such an era. At best they are police craft.

  • 1
    $\begingroup$ "The energy required to move Planetoids dwarfs the effort required to atomize these ships, making even the bombs I'm describing puny." - good point as the rest, the "fundamental problem there" part. However, I'll add a spoon of tar in the barrel of honey(which I really appreciate being mentioned) - chemical bonds are not that bad if they used smart enough. In Op's situation, it is rather a technology of using them is not appropriate for the war situation, as you said, but it is possible to suggest better ways of constructing those ships and make them not so vulnerable to the type of attack. $\endgroup$
    – MolbOrg
    Commented Jul 3, 2017 at 17:59
  • 1
    $\begingroup$ @MolbOrg It is true that chemistry (electron bonds) do "hold up" entire planets, and an entire planet is actually hard to destroy with nuclear weaponry. But gravity is arguably just as important to planetary structure (insofar as it is gravity that keeps it from falling apart). What other chemical bonds stand a chance against atomic level weaponry? $\endgroup$
    – Yakk
    Commented Jul 3, 2017 at 22:09
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    $\begingroup$ True, but it would only be a tiny fraction of the yield presented by the bomb if it did not have the concussion blast/shockwave created by an atmosphere to benefit from. Although some of these problems could be bypassed if you encased the bomb in an air tank. $\endgroup$
    – Efialtes
    Commented Apr 16, 2018 at 14:12
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    $\begingroup$ The radiation flare would be crippling,and so would the EMP, but the blast would be very weak, and wouldn't do as much damage as expected. $\endgroup$
    – Efialtes
    Commented Apr 16, 2018 at 14:47
  • 1
    $\begingroup$ Thank you for the input, I'm saying that the weapon does not change the kinetic energy in a vacuum, but that the pressure wave that is lacking in space is the mechanism that delivers the kinetic energy generated by the bomb to the target. Without the delivery mechanism the bomb can do nothing, it will release energy for sure, but it won't be delivered fully to the target for maximum effectiveness. So its yield will not change, but the damage done will be akin to that of a lower yield bomb. $\endgroup$
    – Efialtes
    Commented Apr 16, 2018 at 15:00

Self-replicating nanobots

There is very little chance that a space faring species that can build ships that are bigger than any mountain in our solar system has not yet gone into atomic-scale engineering. Build something that turns the armour materials into more of itself, do hit and run attacks against the enemy fleet with suicide ships that just crash in the enemy ships. You just need to crash one ship per enemy ship (which can even be so small that they don't notice it on sensors, or can be disguised as an asteroid) and depending on how fast your nanobots are, the enemy ship will quickly be disabled or even eaten alive. As an additional benefit, the enemy cannot salvage whatever's left of the ship.

  • 3
    $\begingroup$ Make sure there's some sort of population counter built into the nanobots so the entire universe doesn't get eaten. $\endgroup$
    – Cheezey
    Commented Jul 1, 2017 at 1:47
  • $\begingroup$ @Cheezey But I like the Replicators! Give them a chance, they're very friendly once you get to know them! $\endgroup$ Commented Oct 20, 2020 at 20:45

I'm with Burki here. A kinetic impactor is all that you need. Since your universe has engines capable of accelerating monstrous megaships kilometers long, with several meters thick armour, you can also accelerate a tiny ship in much less time and/or to a higher speed, depending if fuel is a conditionant or not - if it is not, speed of light should be the fastest non-warping speed your projectiles can achieve.
You can make a light autonomous vehicle with a plutonium or uranium hollow nose and let it crash against the ship at several kilometers per second. The hollow nose is to make sure the uranium or plutonium is critically compressed on impact. Design the vehicles carefully to make the projectile to penetrate just about four or five meters in the hull, then the nuclear explosion will project the rest of the armour thickness as shrapnel into the ship. The thick armour will make this shrapnel to ricochet through the ship - maximum effect for bow or stern enfilades.
With enough speed, as Burki said in the comment, you don't even need the fission part. Just any blunt, heavy object accelerated to nearly lightspeed will do.

  • $\begingroup$ "you can also accelerate a tiny ship in much less time and/or to a higher speed" ... that depends on a lot of factors. A small ship may actually be slower because it doesn't have spare space to devote to engines. $\endgroup$
    – Jules
    Commented Jun 30, 2017 at 10:41
  • 4
    $\begingroup$ The smaller ship that can be made is one made of engines + fuel deposit. If that's 9 kilometers long, 2 kilometers wide, then this is the smallest ship you can build. But I assume the OP's dreadnought, battleships and cruisers have most of its spare space devoted to crew facilities, ammo and supplies storages, life-supporting systems, weapon systems and whatnot. By definition, if you have a ship that has X systems plus engines and fuel, and you strip it of said systems you end with a lighter, smaller ship. $\endgroup$
    – Rekesoft
    Commented Jun 30, 2017 at 12:05
  • $\begingroup$ Possible if you get an engine powered by antimatter... but thats just a hunch and i have no hard science to back it up... but if theres any engine that can get you really fast with little fuel... antimatter engine is the one $\endgroup$ Commented Jun 30, 2017 at 12:08
  • 1
    $\begingroup$ The uranium/plutonium is entirely redundant. You'll typically get about 1% conversion from your bomb -- equivalent to the damage done by accelerating to only 14% the speed of light. $\endgroup$
    – Mark
    Commented Jun 30, 2017 at 22:04
  • $\begingroup$ @Mark True, but since we don't know the specifics about the OP's universe, I don't know if accelerating to 15% of c can be done easily. With our current technology, accelerating a small plutonium probe to 7 km/s and make it explode on impact is waaaaaaay more doable than accelerating a bulk piece of metal to 45000 km/s. $\endgroup$
    – Rekesoft
    Commented Jul 3, 2017 at 6:37

We called it the Tsar Bomba

With a fireball 8 kilometers in diameter, this would put a serious dent in even your biggest ships. And this 50Mt design could scale to 100Mt just by changing the lead surround to uranium.

The question of 'can we make bigger bombs' is already answered here. Gigaton yields, that would turn your Super Dreadnoughts - and any escorts that were too near them - into scrap are entirely possible.

Warp missiles are way cooler, though.

Edit - it's also worth looking at 'Bunker Buster' bomb designs. Even with WWII specs, these can go through several meters of reinforced concrete before exploding. With space battles, missiles can accelerate to much greater speeds. A bunker-buster design - with an extended delay fuse allowing it to penetrate deep into the target ship before exploding - would be even more damaging than a surface strike.

There are also secondary explosions to consider. Battleships of WWI and WWII carried vast amounts of explosives, as the few surviving crew of the Indefatigable, Queen Mary, Invincible, Pommern, Hood, Barham, Kongo, and Yamato would attest - indeed, if your fighters can target penetrating missiles at the magazines of these Super-Dreadnoughts they don't need huge warheads, they just need to set off the warheads of the target. A standard technology of antimatter warheads would be VERY liable to go up in a firework display in an accident.

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    $\begingroup$ Sorry to say, but this is ignorant to the physics. Nuclear bombs are not that good in space - they basically rely on the shockwave from the air. Which sort of is totally missing in space. You loose most of the explosive power simply be lack of medium. Plus, as the explosion similar in all directions - you loose more than half of the effect because there is no ship there to harm. See the good answer from glyphin on your logical errors. $\endgroup$
    – TomTom
    Commented Jun 30, 2017 at 8:01
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    $\begingroup$ Duh, you just fly a small craft up the poorly defended exhaust port while using your pet ghost to help aim. $\endgroup$ Commented Jun 30, 2017 at 8:14
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    $\begingroup$ @TomTom - For the cases we are talking about, even if 10% of the energy of a 100Mt warhead goes into damaging the ship, that's going to leave a serious dent. A penetrating warhead - such as those that have been around for decades - would avoid the problem anyway. A missile that penetrates 100m into the ship before exploding is going to deliver most of the energy to the target. In the meantime, your laser creates a cloud of plasma at the edge of the target via ablation and pumps most of it's energy into that. Is that better? $\endgroup$ Commented Jun 30, 2017 at 8:44
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    $\begingroup$ Hate to tell you, but you need to do some SERIOUS reading. Start at projectrho.com/public_html/rocket/… to get rid of some of the funny ideas. $\endgroup$
    – TomTom
    Commented Jun 30, 2017 at 8:59
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    $\begingroup$ @TomTom - To quote from that page : "But if the nuke goes off one meter from your ship, your ship will probably be vaporized. Atmosphere or no.". What's wrong with my answer? $\endgroup$ Commented Jun 30, 2017 at 9:33

The answer is "Kinetic Energy" as mentioned by several other posters. At even interplanetary speeds, the amount of kinetic energy being delivered by the impact of an inert mass is astounding, and this only goes up (the ultimate example being a RKKV moving at 90% of c, which can destroy a planet). Dumping the litterbox of the ships cat out the airlock could be a dangerous weapon under the right circumstances.

Since arranging for a head on pass might not be a good tactic, and the ship's cat has ways of making its annoyance with people stealing its litter known, we need to find an alternative. Since you mentioned "bombs", the answer is actually using nuclear bombs to drive weapons effects.

A spherical explosion is not very efficient, and since in the vacuum of space energy is only transmitted by radiation, a conventional nuclear bomb is not an efficient use of energy. Using clever technology to direct the energy of a nuclear device, you can create the analogues of shotguns, shaped charges, explosively formed projectiles and even working plasma weapons which focus the energy of the nuclear device in one direction and can deliver effects like driving pellets at 100km/sec (the "nuclear shotgun") to a spear of star hot plasma moving at @ 10% of the speed of light. Intermediate effects like nuclear shaped charges send streams of metal at the target as @ 3% of c.

enter image description here

The basis of everything else: the nuclear energy is preferentially directed through the Channel filler in the microseconds before the device is vapourized

There is an extended discussion of these sorts of weapons here and here, as well as at the ever handy Atomic Rockets website under conventional weapons.

So in some sense, super massive spaceships the size of aircraft carriers and above are counterproductive, given the energies that can be deployed in space. To me, a fleet like that screams "Target!".

  • $\begingroup$ +1 for shaped nukes... But I'd disagree on the usefulness of big ships: Yes, they carry a big, cross-haired "TARGET!" sign around with them, but they are not defenseless. They would defend themselves against nukes by means of targeted lasers. Even if they only manage to detonate an incoming nuke from a few kilometers away, they will easily survive the attack (this is space, after all). And that is assuming that the nuke actually detonates when it's hit by the laser, which is quite unlikely. $\endgroup$ Commented Jun 30, 2017 at 19:06
  • $\begingroup$ Now jsut attack the fleet from several direction with this bomb for maximum effect $\endgroup$ Commented Jun 30, 2017 at 23:09
  • $\begingroup$ Using the OP's assumption that massive fleets of massive ships are in the realm of the industrial capacity of the various factions, you could make the argument that one side could produce thousands of nuclear shaped charge weapons for every single aircraft carrier sized ship. Waves of missiles coming at you from every angle with spears of nuclear driven death will overwhelm any defense system, and the ranges of some of these devices is in the thousands of kilometres. $\endgroup$
    – Thucydides
    Commented Jul 1, 2017 at 6:14
  • $\begingroup$ @Thucydides> Range? Well, in space range might well be pretty much infinite. It's just a matter of how much delay you allow yourself from firing to hitting. In Hamilton's Dawn of Night, similar devices are fired from up to hundreds of thousands of kilometers, their high acceleration allowing them to close in over a few seconds to a few minutes. Damage comes from speed plus whatever propellant is left. Defense is done by intercepting them soon enough so you still have time to dodge the resulting cone of high-speed debris. $\endgroup$
    – spectras
    Commented Jul 5, 2017 at 16:20
  • $\begingroup$ I was speaking specifically of the range of the actual nuclear driven weapons effects from the warheads. Some advanced forms of the CASABA Howitzer have theoretical ranges of 10,000 km, but nuclear shaped charges, shotgun shells and so on have much shorter ranges. $\endgroup$
    – Thucydides
    Commented Jul 5, 2017 at 17:13

Fusion bomb-pumped laser to penetrate the armor. With a normal nuclear bomb, energy goes in all directions, so at least half of it goes wasted into outer space. Note that the effects of bombs in atmosphere are different - blast overpressure and heating of the atmosphere does most of the destruction. In space, you only benefit from the thermal effects, which amounts to about 35% of the bomb's energy. Then, if your bomb doesn't detonate directly next to the ship, even more gets thrown away into outer space.

The energy of your nuclear bomb is better utilized concentrated into a single direction via a laser. The collimated beam of the laser will be more effective at penetrating thick armor and causing destruction once inside.

You may want to check out David Weber's treatment of space battles if you're not already familiar.

Also, diamond is not a strong material. It is very hard but breaks easily.

  • $\begingroup$ The problem is, what happens at the point of impact? We'd probably see the surface turned into plasma, raised to a very high temperature, which would then absorb the rest of the laser's energy and turn into an even higher temperature plasma. The result would be very similar to a nuclear explosion, just at a lower energy level than just detonating the nuke against the armor, surely. $\endgroup$ Commented Jun 30, 2017 at 8:50
  • $\begingroup$ Confusion between hardness and toughness is very common. Good job pointing it out. $\endgroup$
    – spectras
    Commented Jun 30, 2017 at 9:12
  • $\begingroup$ "You may want to check out David Weber's treatment of space battles if you're not already familiar." -- given that the description of the classes of the capital ships sounds very similar to the classes used in Weber's Honor Harrington novels, I would presume OP is familiar with those. But also note that the details of the technology that Weber invented for those novels produce some very specific results in terms of what tactics are viable that may or may not apply in other universes. $\endgroup$
    – Jules
    Commented Jun 30, 2017 at 10:03
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    $\begingroup$ @AndrewDodds - the point of the bomb-pumped laser is that it doesn't produce a single laser beam. It produces an extremely large number of very intense but short-lived beams. It thus scatters the power of the nuclear detonation over a large distance, concentrating chunks of it in a very large number of small areas. So, yes, the energy level is lower than detonating the nuke directly, but (1) you don't need a direct hit and (2) it disperses it over a wider area. It could theoretically be very effective against a large target as proposed. $\endgroup$
    – Jules
    Commented Jun 30, 2017 at 10:08
  • $\begingroup$ do i need to be in direct line of sight if i am going to use that nuclear pump laser? $\endgroup$ Commented Jun 30, 2017 at 11:28

I think the nuke, kinetic, and anti-matter answers are all good and practical. Therefore I'll go plaid.

I'd develop a gravity bomb.

It is a warhead that for a few seconds generates an intense gravity well. The gravity well is intense though not so much that it would devour a ship; it isn't a black hole. The idea is that a sufficiently close "explosion" will apply a significant off-axis acceleration to the ship, or even one part of the ship.

The sudden acceleration will cause the ship's own mass to tear itself apart.

We see this, in a way, when large ships sink. When floating they are very strong. But as they sink bow or stern first, the other end will lift out of the water. They are not designed to support their own weight; they are designed for the water to support much of it. So the ship breaks in half. The Titanic sank this way.

They might have split up or they might have capsized
They may have broke deep and took water
  • The Wreck of the Edmund Fitzgerald, Gordon Lightfoot

What happens here is that a wave lifts the bow of the ship up, and the keel cannot support it. The ships breaks in two.


I cannot tell if you're writing a story or creating a game. If you're creating a game, the "gravity bomb" idea allows you to add "terrain" to otherwise empty or perhaps static (unchanging) space. Now with gravity bombs one can create peaks and valleys (if you also have anti-grav bombs... why not?) of gravity that service to destroy opponents, deflect them from strategic locations, or act as a "slingshot" for your own ships. If they are going to be used to "decorate" space, they probably should last longer than a few seconds.


Shoot cannon balls of anti-matter at them. Then their shielding won't matter and the mass of the canon ball can be quite low. The ships transporting them can thus be small. The mechanism for transporting and firing could be done using magnetism as direct contact is fatal.

  • $\begingroup$ Ships carrying antimatter "cannonballs" sounds like a risky proposition to me, not too unlike the infantry flamethrowers seen around World War I. Operator error, equipment malfunction, enemy fire, even jostling it the wrong way... any of these (or other) causes would cause a munitions detonation, with catastrophic results for the unfortunate wielder. $\endgroup$
    – Doktor J
    Commented Jun 30, 2017 at 13:53
  • $\begingroup$ If your carrier ships were to be hit near where the antimatter cannonballs are stored, goodbye carrier ship. And goodbye carrier ship escorts. $\endgroup$
    – rytan451
    Commented Jul 2, 2017 at 11:26

I don't have many ideas about bombs but tactically, in the place of this noble, I wouldn't use carrier theory. Space battles are more likely to take place at ranges so great that ships will likely never see each other. This is the domain of Battleship theory which is all about guns and speed. Carrier is about mobility and defense (Carriers rarely go at full speed because they can out run their escorts, which is suicidal. Carrier Theory relies on escorts to protect the Mobil landing strip).

You're correct in wanting to fight up close. Enemy seems geared for long range combat. Carriers here would no be ideal as the escorts would be inefficient defense to range combat and the carrier will be the largest target in play. Even if you stealth it, returning attack vehicles will give general location spread. Battleship theory is also better here as it's all about knowing not just where your target is, but where they will be when the bomb arrives.

Instead, focus on submarine tactics, especially if you're limited and range rules the roost in tactics. The guns will likely be inefficient to target an enemy that's close, too prone to friendly fire to be operated, or both, if it's a difference between a few kilometers and a few light years.

Both rely on getting close to ships without much point defense. A small one man fighter is a smaller loss than a sub, but you lose all if they return fire on the mothership. Stealth subs like ships have the ability to hit and run, line up critical shots, and confuse numbers (is it one side or one hundred?). A bomber might be less likely to hit, but a sub can at these size get just as close plus bring more things that go boom. It also puts your more valuable ships in a safety range. Your bombers are never more important than your carriers. Carrier tactics today work because Battleships can't hit a target in an airplanes flight range. But in space, and in your scale, you're dealing in ranges that make both on equal terms. The biggest threat are those that you don't see.

With that in mind, I'd push for higher stealth and mobility especally if my fleet size is limited. Also it allows for tactics that don't destroy the ship, but leave it down. You can also get more bang for your buck not by getting a bigger bang but using a small bang in the right spot. A cherry bomb doesn't normally do enough damage to down a 747... but it can if you realize that the most vulnerable spot is under the pilot's seat.

  • $\begingroup$ i really like your idea. But i stand by my side using a covert warp capable bombers to do the dirty work of my carrier. This carriers will operate independently from each other in what i will call raid patrol deep inside enemy territory where manufacturing and refitting stations are abound. A ship after all doesnt exist if its not seen after all. This carriers are capable of cloaking themselves, launching and recovering fighters undercover of cloak while still capable of communicating FTL. $\endgroup$ Commented Jul 20, 2017 at 13:07
  • $\begingroup$ Carriers do not operate independently though. Traditional naval carriers are often protected by a series of ships and themselves have little in the way of offensive or counter offensive arms. Part of the problem of why carriers can't do that is because the deck space needed to launch and recover limits the amount of armaments and the size. It's not a problem on a space ship, where the hangers are presumably inside, the exterior can still be armed. Naval carrier theory will not translate well to space because this is such a fundamental issue, that most carrier tactics are built around it. $\endgroup$
    – hszmv
    Commented Jul 20, 2017 at 16:04
  • $\begingroup$ Well, this are the first carriers... and literally the only carrier at the moment. Increasing the number of escorts of this deep penetration carriers will further increase the risk of it being discovered. The idea that this carriers can hide inside enemy lines and strike targets of opportunity with impunity allows this kind of striking power unmatched and unrivaled by anyone at that time where it is the only carrier, no one has thought of arming shuttles with anti super capital weapons and most definitely not thought to be warp capable. I am banking on those facts for it to be able to operate $\endgroup$ Commented Jul 20, 2017 at 16:21

In your universe, people can move planets. By nature of this being possible, you can build some AWESOME weapons. One I would suggest is the "planetary nutcracker" concept, where you move two planets on the opposite sides of a fleet or planet, and launch them towards each other. Given the size of the ships involved, and that they use fusion as power, the bombers themselves are effective weapons. You might be better off shooting a gutted one of those at the enemy.


Heres my Idea: If you contain about 20 grams of ionized hydrogen in a 1cm in diameter steel sphere, when the sphere breaks it creates a 1.5 megaton explosion due to the repulsive forces generated by the hydrogen ions. The hydrogen would burst forth in an expanding cloud of plasma that propagates at lightspeed and would shred everything. It would be environmentally friendly because it won't create toxic radiation. So you would just scale up the device as needed. To break the sphere you just surround it with a C-4 shaped charge and an oxygen tank designed to tear apart the shere from all directions.

  • $\begingroup$ Ionised gasses inside a significantly more massive conductive sphere will tend to not stay ionised for very long. $\endgroup$
    – user31336
    Commented Apr 16, 2018 at 17:39
  • $\begingroup$ The object is not to create a bigger sphere but rather to stuff the sphere with more hydrogen ions to provide greater force. $\endgroup$
    – Efialtes
    Commented Apr 16, 2018 at 19:47

I will stick to the mass+velocity solution. Plus i add that there is no practical need to distinguish ship from payload. Been unmanned, those bombers would actually be a set of engines for thrust, their fuel, the CPU and all the rest mass will be front armor and nothing else, to protect against some enemy fire(actually mostly against other object the bullet-ship will encounter before impact). Stealth is not needed. With a velocity of 0.9 c and the slightest ability to change direction it is a joke to talk for counter fire that will turn that ship-bullet to harmless dust. Hitting that large targets though is piece of cake. Depending at what type of mass is used, chances are that the ship bullet could even hit more than 1 targets if inline, or, if mass vaporizes while within the target, the effect will be that of a shotgun at 0 range.

And the noble hero favorite quote: Welcome to the bullet-ship era!


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