Let's say you want to build a weaponized Spaceship with near future technology.

It's goal would be to be able to destroy satellites, other weaponized spaceships and projectiles/missiles shot at it from Earth.

By near future I mean that all those parameters can be at most an order of magnitude (10x) better than what we have now:

  • Size of the spaceship (including weapons)
  • Energy that can be carried/produced by the spaceship
  • Efficiency of said weapons

In that context, what would be the most efficient weapons that you would want to carry on such a spaceship?

I broadly categorize weapons in 3 categories

  1. Projectile-based: canons firing some projectile that can potentially explode on contact with the target

Would have limited ammunition but doesn't require any energy source. However, any kinetic-based weapon would push the spaceship in the opposite direction after each shot; I'm not sure if it s doable. I also think it couldn't be used to intercept projectiles shot at it since it wouldn't be precise enough.

  1. Lasers: high energy beam capable of burning materials

I'm not sure we would be able to generate enough energy on a spaceship to fire a laser capable of some decent damage. If it was possible, it would seem like the best solution since it could also be used to intercept projectiles.

  1. Missiles: thermonuclear missile

Since spaceships would be incredibly fragile, I think #3 would be overkill. However, it could be useful for intercepting/deflecting projectiles/missiles shot at the spaceship from another spaceship or from the ground since it has a large area of effect. The missile would ignite after being detached from the spaceship to prevent the action-reaction effect from pushing the spaceship in the opposite direction.

What would be the weapon of choice for a near-future weaponized spaceship?

  • $\begingroup$ Would a hydrogen bomb even work properly in space? $\endgroup$ Nov 21, 2016 at 8:00
  • $\begingroup$ It would be cheaper and easier to deploy surface to orbit missiles that simply are launched to pop-up and intercept satellites and spacecraft as they pass overhead. These are effectively rocket-propelled artillery shells. Orbital vehicles will run into them at 8 km/s. The payload can be almost anything -- gas, dust, small pieces of metal, or even explosives. For the near future this beats weaponized spaceships. $\endgroup$
    – a4android
    Nov 21, 2016 at 11:39
  • $\begingroup$ @HarryDavid Atomic based weapons in space do "work", but there is no traditional blast that we are familiar with from being on the surface of a planet and surrounded by matter. There would be a flash, and radiation that could cause ablation, but no "shockwave" as we traditionally understand it. Radiation also would fall off as per the square-cube law, so your "dangerous radiation" range is also not huge if your ship is properly shielded. $\endgroup$
    – Marky
    Nov 21, 2016 at 14:31
  • $\begingroup$ whole site dedicated to the argument, go nuts. projectrho.com/public_html/rocket/spacewarintro.php can be summed up as in space missiles>kinetic>laser $\endgroup$
    – John
    Nov 22, 2016 at 2:03
  • $\begingroup$ I would prefer missiles, if to be short, or this $\endgroup$
    – MolbOrg
    Nov 22, 2016 at 9:51

6 Answers 6


Against earth-launched objects the ship is dog meat regardless of weapon. Assume the ship is in LEO, with an orbital velocity of roughly 7 km/sec. While the ship is on one side of the earth, on the other side a ship-killer is launched. This also reaches LEO, but going in the opposite direction. Its payload is several tons of ball bearings, which it disperses before coming into sight of the ship, and does so in several waves. Closing velocity is 14 km/sec. While radar might detect the cloud(s) of bearings, there is basically nothing that can be done, especially if the ship-killer deploys ECM to mess with the ship's radar. Even an H-bomb won't have much effect, since even if molten the bearings won't be deflected much and will still have their original velocity. Plus, of course, there are several more waves coming, and the first nuke will serve as an excellent ECM device in its own right. Or, just for fun, the killer vehicle can preemptively deploy a few nukes to mess up point defense.

If you want to get even nastier, you can coat the ball bearings with radar absorbant paint.

  • 1
    $\begingroup$ You could use ping pong balls to get, roughly, the same impact. Choose radar transparent ping pong balls for preference. $\endgroup$
    – a4android
    Nov 21, 2016 at 11:34
  • 2
    $\begingroup$ Nasty weapon indeed... it has one small disadvantage: The planet deploying this weapon might find it hard to have any satellites in orbit, let alone anything manned, since your ship killer will have near-unpredictable positions pretty soon. Unless you found a way to disperse your projectiles on a degenerating orbit, which might be hard for this kind of payload, i think. $\endgroup$
    – Burki
    Nov 21, 2016 at 15:15
  • 4
    $\begingroup$ @Burki - You are right, of course. But hey, nobody ever said war is without its inconveniences. $\endgroup$ Nov 21, 2016 at 15:16
  • $\begingroup$ Not bad, but there are some weaknesses. The sheer orbital velocity is overkill only on LEO, when the ship orbits higher, it is slower, and there is more time to evade. Although the projectiles themshelves are shealty and durable, the launch vehicle is probably not. So an attacking force could distribute it's ships on orbit, that they could see the whole planetary surface and fire at any rocket launch. Even if the ship-killer manages to reach orbit, they can warn the other ships, and a tiny burn would be enough to avoid the kinetic minefield. $\endgroup$
    – b.Lorenz
    Apr 23, 2017 at 16:27

Short answer:

all of them and something more

Long answer

Projectiles vs missiles

In 1950-1960 missiles was developed so powerful and developing was so fast that many people thought we don't need artillery and guns anymore. All we need is different rockets. But they were wrong: missiles have not only advantages. Nowadays ships, aircrafts and tanks have both missiles and guns. They are using on different targets. Based on today's reality, in your world

  • Lasers
    • the fastest weapon since nothing could be faster than light
    • perfect as a long-ranged weapon
    • could get the energy either from rocket engine or from explosion or even nuke
    • gamma-ray laser bean couldn't be reflected. We couldn't construct it yet - our technology is unsufficient.
  • projectiles
    • I suppose railguns are preferable than firearm guns in the space
    • slow, mostly non-manageable
    • but much cheaper than others
    • perfect for orbital wars: add projectile speed (0-1-2 km/sec) to target's orbital speed (7 km/sec) and difficulties with maneuvering
    • reciol matters. It's complex but solveable problem so negative effects could be reduced as it reduced for naval artillery and aircraft machine guns
  • missiles
    • could carry much more load then others
    • able to maneuvering
    • the slowest weapon
    • could be easily detected and intercepted
    • very similar to modern torpedoes: a powerful but slow weapon with short range.

Note that nuclear bomb would damage the spaceship although it less effective than in Earth.

Something more

  • Particle accelerator
    • relativistic particles (0.1-0.5c) are slower than light only
    • could cause induced radioactivity
    • could change structure of target's hull so it would be brittle, weak and couldn't protect anymore
    • long-term exposure needed
    • most likely it could act like a catapult: weapon to destruct enemy's defense and useful in siege only
  • Self-replicating nanorobots
    • use the hull of target to produce own copy
    • could easily destroy anything if reached target
    • in this post this is the most fantastic weapon
  • Anti-matter
    • safe while within (magnetic) shield
    • most powerful weapon
    • best for proximity bombs

10x better than today

I suppose with that scale quantity goes quality. It looks like mediveal musket vs modern assault rifle, wooden line-of-battle ship vs steel battleship. I haven't any numbers to compare although.


Lets for the sake of argument say that your spaceship is sized for one person and has the basic looks of a fighter jet.

First of all, I'd suggest cooling your engine using liquid helium and cover the entire ship in radar wave deflecting paint, this way your ship will be almost invisible to thermal and radar.

Second: I would go with lasers because they can be precise and there is no extra weight added because of ammunition/rockets. Also, rockets in space have an extremely high turning radius since there is no friction/gravity.

Third: If the technology is actually 10 times the current they will highly likely have fusion reactors which can generate so much power you could probably install an EMP into your arsenal. Just make sure you disable all electronics (kill switch) before activating and you should be good.

Fourth: By having only a Laser and maybe an EMP you can save up on, Rockets and Projectiles which add weight to your ship and can deplete if the firefight is long enough. For example, A minigun can shoot for about 10 seconds... it's high damage but it won't help you lots in fights. Lasers run of the auxiliary power in the ship so if you have enough power you can keep them online indefinitely.

Bonus Point: Keep in mind that lasers do use extremely high amounts of energy to stay active that is why I mentioned the fusion reactor. Alternatively, you might try a particle beam.

  • $\begingroup$ Fyi* Shooting a rocket is harder than you think that's why I mentioned the EMP so you can simply scramble there tracking sensors and maybe even disable them. $\endgroup$ Nov 22, 2016 at 8:11
  • $\begingroup$ One that is coming at you* $\endgroup$ Nov 22, 2016 at 8:11

Ships in space and basic shielding

Any combat ship in space has a problem, it has to be strong enough to endure without significant damage, a simple impact with an object at very high speed. You can try to maintain our current system of ships that need to be as light as possible to maneuver with the drives we have, but to build ships of the type you're asking for, new drives are required. To consider the building of combat ships at all you're now considering a massive increase in orbital debris in a short period of time, you're going to have to build to a spec that can withstand such impacts.

This makes big heavy ships with potentially limited maneuverability. Somewhere along the line is an ideal point which will withstand the impacts and still be able to move, but the basic requirement of construction means that dumb ballistic weapons are largely useless.

Radiation shielding

How much does it need? How much radiation from a solar storm, how much from a nuclear explosion at close range. The former is what you're shielding against as a baseline, the latter is what it has to resist in a combat situation.


This is the only one on your list that the ship doesn't need resistance to just to be able to operate in the situation you've described, meaning that this is could equally your baseline for ship to ship weapons. However their power is often limited, if I can defend against it by putting a bit of roll on the ship so the beam doesn't remain in one location for long enough to cut through, this weapon equally becomes useless.

Smart magnetic missiles with shaped charges

This is the way I'd actually go in practice. Rather than impact based weaponry I'd develop a missile that magnetically clamps to the outside of the target ship to ensure that the shaped charge has the best chance of penetrating the hull. Nuclear is not required, a conventional explosive with oxidiser that works in a vacuum is quite sufficient if correctly applied.


Lasers Would Win

Given the information, I'd like to say theoretically lasers would win this battle. However in the parameters set it would be pretty limited.

Battle Usage

It is described as being able to burn through materials. When compared to a satellite it could be used to melt through some key points such as solar panels.

Energy Usage

This is a very strong down point for lasers, however there are ways to minimize energy usage. Instead of having it be like a combat spaceship such as star wars, it could be used as an orbital beam. Conserving energy by travelling via orbit. It could also use the assistance of other spacecraft to supply it with energy. Another point I'd like to make is the existence of the sun, especially since its an orbital craft, it could use solar power, convert it to electricity, and power the laser.

Also considering we have machinery as strong as a hadron collider, a basic laser beam seams feasible enough in due time.


Although lasers would need more sustainable energy, I'd like to argue that a projectile would need a lot of energy not only to blast it through the vacuum of space, but also go either fast enough or be strong enough to damage something in space. In this case a satellite.

Hydrogen Bomb

Though incredibly powerful, it comes with a lot of risks. For one you're launching a hydrogen bomb in space which, in my mind would travel at slower speeds than most projectiles. Also the blast radius is really high so you'd need enough power to bail before it can detonate.

  • $\begingroup$ " be strong enough to damage something in space." In general, space-borne structures are as light as possible, since maneuvering is expensive and fuel requires more fuel to move it. Light as possible means weak. Armor plate is not remotely an option. There are designs for strong ships, but they have the drawback that they cannot maneuver worth squat. $\endgroup$ Nov 21, 2016 at 15:13

I'd go with an entirely different approach. Use orbital flight mechanics to your advantage, and use your targets kinetic energy to your advantage.

First, some facts on orbital movement:

1) You will not change your flight direction easily without expending very large amounts of your delta V budget (i.e. fuel / engine burn time) in the process. Especially not rapidly.

2) You are not stationary. Ever. In fact, you are going mach 25+ on just initial reentry, LEO speed is even higher, and higher orbits will need even more.

3) your path is predictable, unless you are stealthy. Which you are not, because you are hot against space background, even if you limit radar signature.

Now, considering that your target is moving at orbital velocity, on known trajectory. Lets place a steel/titanium net of thick cables on his path. A net that is 500-1000 meters wide each side. Moving at orbital velocity. On his orbit. In the opposite direction. With limited maneuverability and sensors, so they cant get away that easily (unless fully commiting to either leave orbit, by expending his dV budget, or deorbitting altogether)

edit: for better effect, make it unfold a little time before predicted time on target, and have a compact, easy to hide missile form before that. For even better effect, launch several on different, tailored trajectories , of which some are designed to intersect possible favourable escape routes.

Now, we wait.


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