In a setting with (mostly) near future technology what material would a top end naval spaceships hull be made out of?

The hull must follow the following requirements:

  • Able to withstand the strains of space travel (containing internal atmospheric pressures, radiation shielding, microscopic impacts on a ship hitting 400000mph etc)
  • It doesn't need to be able to land as the ship was launched from and will remain in space throughout its life.
  • Armoured from attacks of anything up to a large non-nuclear missile.
  • Not required but worth bonus points: resistant to corrosive, electrical or any other weird attack you can think of.

The materials you can use are:

  • Any material we have now/will probably have in the next 30-50 years. There is a lot of interstellar trade so most raw materials are available and the navy is willing to pump in a lot of funds so cost is no barrier.
  • The hull can be made of more than one material if you think this would be a better option.
  • $\begingroup$ Since when strains of space travel include pressure? You mean lack of external pressure or you want to be able to fly into gas giants? Or what, exactly? Also, how large missile? Compared to the size of ship? $\endgroup$ – Mołot Apr 24 '17 at 21:06
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    $\begingroup$ @Mołot Sorry, I meant that it needs to be able to contain internal pressure.I will edit to make that clearer. $\endgroup$ – Bellerophon Apr 24 '17 at 21:08
  • $\begingroup$ Or maybe not, seems I can't edit. $\endgroup$ – Bellerophon Apr 24 '17 at 21:11
  • $\begingroup$ A missile smaller than the ship that fires it. More seriously I haven't fully decided yet but basically the bigger the missile it can survive the better it is. $\endgroup$ – Bellerophon Apr 24 '17 at 21:36
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    $\begingroup$ "Armoured from attacks of anything up to a large non-nuclear missile." this is not really possible in the reality of orbital movement mechanics. Speeds and energies involved (especially on head-on closing collision trajectories) are way too high, especially if a dedicated kinetic penetrator is used against you. $\endgroup$ – Michał Jastrzębski Apr 27 '17 at 8:53

10 Answers 10


Why bother selecting only one material when you can have several?

Composite Armor

Composite armors are made up of layers of material that each can absorb, reflect, or neutralize different types of kinetic and energetic impacts. Each layer can be specialized for different kinds of space-based interactions, and deployed as modular panels that can be replaced with (relative) ease. Furthermore, you need not rely on future materials, but instead on materials that are already well-studied an in use today.

Outer-most layer - Ablative (thermal soak, carbon phenolic) for dissipating high-heat radiation and slow down impactors

secondary layer - ceramics for dissipating the high energy of kinetic impactors

Tertiary layer - Explosive reactive armor to reduce the effectiveness of high explosives (large missiles) and defeat/redirect any impactor that has made it past the other layers. This also manages to generate deadly debris fields by ejecting the ceramics layer pieces as high-velocity projectiles.

Inner-most layers - heavy metal alloys (iron, steel, etc.) for structure, and to absorb large amounts of radiation

Of course, these can be rearranged to suit needs, and other layers can be introduced as needed for more specialization of craft. Each successive layer will go further towards defeating those unconventional attacks as well.

Exactly how this armor is deployed is pretty flexible as well. My mental picture is of the interior structure layer being mostly solid - forming the true hull of the ship - and it is surrounded by panels containing the other layers. Due to the reactive armor and ceramics, a strong enough impact or detonation will make a given panel or area of panels weaker or useless, and will require they be replaced. Automated ship repair utilities can make this a bit less of an issue, especially in combat contexts.

There are, of course, cons to this armor type, which deal mostly with great overall thickness and cost. That being said, cost is not an object, and thickness would come secondary to protection on a multi-billion dollar space vessel.

  • $\begingroup$ This is a good answer. Just a small comment, I wouldn't want ERA anywhere inside my armor scheme, considering it's designed to explode. Typically ERA is fitted as an external 'add-on' to tank armor, also having the benefit of making it easy to replace after it's triggered. $\endgroup$ – Catgut Apr 25 '17 at 14:25
  • $\begingroup$ Thank you, Catgut. I have edited the post to include a design based on modular panels to allow for replacement of these detonated sector, based on your comment. $\endgroup$ – Tmartin Apr 25 '17 at 14:59
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    $\begingroup$ Well, the other aspect I was getting at was that if ERA is underneath other layers of armor, the ERA will be detonating into the armor. That's not a very good situation to be in, and a 'successful' ERA activation would likely compromise large sections of the the armor above it (or worse- the external armor layers would reflect the explosion back into the ship). To my knowledge ERA is never used anywhere but on the outermost layer of armor. $\endgroup$ – Catgut Apr 25 '17 at 17:34
  • $\begingroup$ Ceramics don't work at these speeds, as the projectile is moving faster than their speeds of sound. $\endgroup$ – DOS4004 Apr 26 '17 at 5:04
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    $\begingroup$ Putting your reactive layer as an inner layer is a phenomenally bad idea. The force of the explosion will be directed inward - do you really want to kill the crew? Plus, reactive armor is only effective against shaped charge penetrators, so is useless against any likely space muntions. So your proposed armor a) won't stop penetration, and b) will injure or kill the crew. Whose side are you on, anyways? $\endgroup$ – WhatRoughBeast Apr 26 '17 at 16:36


  • Styrofoam or other expanded polystyrene foam has low mass. Low inertial mass means cheaper to move and cheaper to stop.

  • Styrofoam ship can be immense: a cubic kilometer or more. It will be hard to know where important parts are on the inside.

  • Foam ship is easy to repair by adding more foam.

  • Explosives detonating on hitting foam ship blow away pieces of foam. Hard ship pieces themselves do not become shrapnel / projectiles to carry energy deeper into the ship.

  • High velocity projectiles pass entirely through the ship and out the other side. Ship is held in tension and so seals itself if pressure containing space is traversed.

  • Styrofoam is cheap. Money saved can be used to buy more styrofoam and make ship bigger.

    • Styrofoam is very flammable. Fortunately there is no oxygen in space.

    • If additional radiation shielding is desired this can be done using large quantities of water contained in spaces within styrofoam.

    • If additional projectile shielding is desired this can be accomplished in an ad hoc manner by venting large quantities of water to occupy space next to object being shielded.

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    $\begingroup$ Beware floating glue clouds ;) $\endgroup$ – O. R. Mapper Apr 25 '17 at 5:12
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    $\begingroup$ The only way I can one-up this answer to to go "nu uh! aerogel!" $\endgroup$ – Draco18s Apr 25 '17 at 20:06
  • $\begingroup$ One problem I could see is that Styrofoam is a very good insulator and thus such a ship would find it very hard to expel waste heat. Other than that possibility great answer! $\endgroup$ – Ummdustry Dec 29 '18 at 15:07

There's lots of sci-fi in which they basically take an iron-nickel asteroid close the sun to burn off excess material and then bore our the center - sometimes elongating the molten blob first to form a cheap, thick hull - the more resistant dependent on thickness and mass more than exotic material. There are others in which cheap silica/aluminum moondust is compressed and heated to form ablative plate armor.

  • $\begingroup$ Seems like a basis for a good answer, could you explain how the hollowed out asteroid would be good at matching the requirements? $\endgroup$ – Bellerophon Apr 24 '17 at 21:12
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    $\begingroup$ The fundamental strength of such a design is cheapness. You're using cheap materials to form a very thick hull. More armor = longer time it takes for the enemy to pound through. Also it has the benefit of radiation resistance. More mass = more radiation resistance. That's why they put the lead apron on you when you get x-rayed. As far as exotic attacks, again - mass. Push lots of whatever against the hull and the mass dissipates it. $\endgroup$ – Blackbeagle Apr 24 '17 at 21:36
  • $\begingroup$ For what its worth, this is how I would do my ship. Instead of the process you used I would take the regolith from the Moon (as an example) and coat the the "functional area" with it. BUT Hollywood has implanted the Sleek, Sexy Space Ship image in our brains. Of course nothing about space says that design is any better than any other design, from a inter planetary travel/movement perspective. Want to mine an asteroid process it and send it to a "facility" build the ship from the "unusable" parts of the asteroid and attach an engine. $\endgroup$ – Enigma Maitreya Apr 25 '17 at 15:56

I think this very much depends on types of things you want to protect yourself from.

Currently, we don't really "armor" spacecraft for any type of combat. We have heat shields and/or ablators for re-entry, and then some dense foam-like material for absorbing micro-meteoroid or debris impacts.

"Realistic" magnetic shields would protect from plasma or solar radiation or even possibly some particle weapons; but deflecting terrajoules of energy is pure sci-fi for any magnetic defenses.

Particle beams or bolts could be countered by ejecting reflective chaff or dust that absorbs, refracts, or diffuses the energy.

Above answers cover missiles and kinetic impactors fairly well.

For materials, you want something dense but slightly malleable for your kinetic ablator, and if we are talking "near future" this will likely be some type of memetic nano-material; self-repairing high-carbon ceramics like that "kinetic putty" stuff infused with ferrous material and both physically and magnetically attached to the hull. When your kinetic impact (or a missile) hits (whatever gets through your point defenses and outer reactive armor layer) the ablator is deformed and bits of it blown off the hull, but what is not obliterated or ejected too far from the hull would be attracted back by magnetic force and then reformed by the materials 'memetic' properties.

You'd probably want two reactive layers - an outer layer that does not cover all surfaces, but the effects of it would. Think the reactive packs on modern tanks; they only cover a small part of the tank's surface but protect from attacks coming in on most any vector. Then you have your "armor" layer (ablator, mostly) then you have an under-layer of emergency countermeasures, then you have your primary and secondary hull.

Point defenses and counter-measures would be highly preferred over actual armor, as well. Maneuverability is a better defense than armor, particularly at very long ranges where any incoming attack would take seconds, minutes, hours to arrive on target. If you have a particle beam with an effective range of 1 light second, this is "close range" for such a weapon (less than 1 second for target to detect and respond to the incoming attack.) With railguns: 5,000 to 20,000 meters per second projectile velocity would give them "effective" ranges of maybe 100k meters. Sure, the projectile will keep going past that, but the target will have seconds to minutes to plot its trajectory and move out of the way.


Why not just invent your own? Lots of writers do it too. Not just like explained away style either.

In my own sci-fi universe I have a material that's essentially a Carbon/Iron/Titanium alloy called Damascium after Damascus Steel. The idea is that since they have recently discovered carbon nanotubes in actual Damascus Steel, they finally reverse engineered it and added in some Titanium and a few other elements and...voila, a super light, strong, non-magnetic metal for spaceships.

Reasonably believable, composed of fairly common resources, and I can manipulate its properties somewhat as needed without having to actually do much research. 3 birds with 1 stone.

  • $\begingroup$ Glad to help. I will remove my comment and after you see this comment it too shall go away. $\endgroup$ – a4android Apr 25 '17 at 4:33

What would you make it out of? Carbon fibre, titanium, carbotanium.

But I can't see there being any point in spacecraft being armoured. Think of the speeds involved with spacecraft, and then think what a fairly small depleted-uranium penetrator is going to do to even a fairly well-armoured craft. As we're talking near-future, what is the plan to get all this weight of armour into space?

Modern sea-going warships aren't armoured simply because it's not possible to armour them against likely threats - much better to save resources and build more ships, or concentrate on offensive weaponry and defensive systems instead.

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    $\begingroup$ DU penetrator? Can we have that in plain English not acronymese, please? Yes I can do a Google search to decode the acronym, but I've been doing this too often now and the fun is wearing thin. $\endgroup$ – a4android Apr 25 '17 at 4:11
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    $\begingroup$ As pointed out in the question, the weight does not need to be lifted into space as the ship is built, and launched, from orbit. The materials will either be flown up in supply ships or, more likely, special ordered from the mines on other planets, moons and asteroids. $\endgroup$ – Bellerophon Apr 25 '17 at 15:23
  • $\begingroup$ Ah, missed that point. Even without weight though, the rest of my points still stand. When things are moving at tens or hundreds of thousands of metres per second, armour isn't going to make much difference. $\endgroup$ – Matt Bowyer Apr 25 '17 at 16:23
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    $\begingroup$ DU means depleted uranium. Meaning its depleted (instead of enriched) of its radioactive isotope, U235 - leaving inert U238. Its very heavy, very dense, and very rigid, thus works wonders as a kinetic penetrator (and is used routinely IRL as such, i.e. in a A-10's GAU-8 Avenger 30mm cannon round, and many others) $\endgroup$ – Michał Jastrzębski Apr 27 '17 at 8:59

Ok, first we want a multilayer hull for our ship.

All Layers will be constructed from Nanobots as in self assembling and repairing units.

Plasma Shield Layer

This layer will implement “designed” magnetic Fields that will contain our Plasma Shield by using specifically designed nanobots. This layer will have as many replacement nanobot layers as deemed appropriate.

“Students prove real-life Star Wars deflector shield is possible” - https://www.extremetech.com/extreme/181773-physics-students-figure-out-how-to-make-star-wars-deflector-shields-in-real-life

“Computers Create Recipe for Two New Magnetic Materials “ - https://pratt.duke.edu/about/news/predicting-magnets

The Plasma Shield will be resistant to most all forms of attacks and encountered objects. The plasma and the magnetic containment system will be dependent on supplied energy.

Based on work done from the 1960’s to early 1970’s “Project Rover“ - https://en.wikipedia.org/wiki/Project_Rover We get to Nuclear Thermal Rockets the part here is the Nuclear Reactor part that was certified space worthy before the funding was cut. Advancements here can supply up to 25 Gigawatts of power per generator.

Heat and Kinetic Energy Layer.

There will be multiple layers of interlocking Nanobots designed to provide maximum stress protection. Damaged units will be repaired by removing for recycle purpose any unit that falls below a specified value and replaced by the nearest unit beneath it. This will propagate through to the most inner layer of protection. The recycled remains of failed units will be used to build new units.


There are three things the armor needs to defend against: kinetic impacts, lasers, and ionizing radiation.

For kinetics, you want a Whipple Shield, a thin layer of material to shock the projectile into plasma, and another layer to block the resulting shrapnel. You want the two layers to be very far apart so as to allow the shrapnel to dissipate. In some cases, making the armor thicker makes it worse, as the thicker outer layer generates more shrapnel.

Lasers can cause damage by either heating the target, or by pulsing fast enough to blow pieces off. To defend against this, you need a material that is reflective, has high heat capacity or thermal conductivity, and will ablate away slowly when being fired at repeatedly while still remaining reflective.

Radiation protection would either be used to defend against the background radiation, or to protect against particle beams and nuclear weapons. Radiation armor could be supplemented with a magnetic field generator to protect against bremsstrahlung.

Radiation armor would be the innermost layer of armor, followed by a whipple shield, with some anti-laser reflective-ablative armor on the surface. There is a tradeoff between anti-kinetic and anti-laser armor, as too little anti-laser armor will allow the enemy to burn through the whipple shield with their laser, following up with kinetics. On the other hand, too much anti-laser armor will generate more shrapnel when hit by kinetics.


If you assume you can launch everything in space, I've an historical approach to build a really large ship which is extremely tough: a bunker space craft, made out reinforced concrete.

Explanation I live in Brittany where the Nazis during the Second World War created three extra resistant bunkers. This is the submarine base of Lorient, Wikipedia article here (sorry this is in French, can't find the English one). It's part of the Atlantic wall but that is not the point here. The point is this is really resistant. In fact, virtually indestructible. The allied forces bombed it with a Tall Boy (2 tons of explosive bomb), it made a large crater but the bunker was still functional. This is because of the architecture.

Architecture The roof of the bunker is composed of two layers: a layer 3 meter thick of concrete beam, use to provoke the explosion, an empty space, playing the role of explosion chamber and the real roof 3 meters thick again. It provides a close to indestructible roof.

Adaptation to a spacecraft The spaceship is contain in the centre of the concrete structure, it could be a battlestation (like the Death Star) or a battleship, but it shouldn't be a little shuttle, it would be ridiculous. The bunker I told you is a submarine base, the ship could be a vessel carrier too.

Scenario advantage Things which look like Nazis make easy villains (like the Darth Vader helmet or Imperial officer in Star Wars).

Issues It's hard to include weaponry and propulsion without creating weak point. It's hard to send into space.

I hope it will help!

Edit: Here is the English article but it is far from complete, comparing with the French one.


I thought it worth mentioning something that isn't a solid. I would consider (being in the future) several hundred kilometers wide orb of a gas held in place by the gravitational mass of the ship. Who knows? Maybe having your own atmosphere pays in space. objects would burn up as they get close... the diameter of the gas would be just sooooo large that it would be unlikely armor. In deep space there's no reason not to have a non solid as your skin. Perhaps it's easily dispersed but easily replaced like a spider, spraying out a substance that expands from a "dormant" state and/or compressed gas canister yadda yadda. It's space! You could have a bubble the size of a planet if you wanted. No need for flimsy cracker and biscuit plate armor that makes it hard to launch. blech.

  • $\begingroup$ or a solid state, using future tech to turn a little ball of solid into a million cubic acres of the same stuff in gas form? sounds pretty heavy. oh well $\endgroup$ – christopher brander Dec 18 '18 at 15:31
  • $\begingroup$ right direction of thinking $\endgroup$ – MolbOrg Dec 18 '18 at 17:35

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