Space Warfare - How would the ships be built/designed?

[RizzoTheRat]

Or Rocket, Artillery and Mortar (RAM) point defense. The HEL TD and other prototype laser systems have already shot down incoming mortar shells at representative ranges. Don't forget, that lump of metal is encasing several kilograms of high explosive, which becomes rather hum, shall we say, "interesting" when you warm it up.

I hadn't realised they'd actually shot them down, I thought the idea was just to disrupt them enough that they wouldn't detonate on impact. tThe YAL airbourne laser was supposed to hit missiles in the boost phase when you'd only need a pretty small amount of damage to knacker the whole thing, but THEL appears to have "shot down" several mortars, and even artillery shells, which must mean detonating the explosive inside. Considering they're built to withstand about 15000g on launch I'd guess the explosive is pretty stable so that must be putting a hell of a lot of energy in to it.

Every day's a school day

[Kibble]

BTW lasers on satellites, since they will only ever in their life cycle fire for maybe a few seconds, but at unpredictable times requiring very high power, will be powered by hypergolic (hydrazine/nitrogen tetroxide or something) fuel cells. Because there will be limited fuel for the laser, it will also be most mass efficient to dump the waste heat into coolant and vent (from at least two symmetrical places) into space.

[Rune]

Every day's a school day

It is, isn't it? For you and me both!

Rune. The day I stop learning will be the day I die.

[Rakaydos]

That's the Orion battleship. We could have built it in the 60s.

[Frozen_Heart]

That's the Orion battleship. We could have built it in the 60s.

It would also be practically useless.

The only targets in space are satellites in earth orbit. ASAT missiles or missiles on other satellites are enough to destroy them. If that thing came close enough to fire at them then a simple ASAT missile could destroy it in return.

Of course its drive mechanism could knock out everything in earth orbit... including your own stuff.

[Rakaydos]

I dont think an ASAT missile is going to do much if orion can get it's pusher plate between it and the attack.

Edit: also beside the point- in a hypothetical interplanetary conflict, there WOULD be targets that cant simply be hit with an ASAT weapon.

Edited September 7, 2015 by Rakaydos

[tater]

Any sufficiently interesting (or effective) propulsion system is also a weapon.

[More Boosters]

Any sufficiently interesting (or effective) propulsion system is also a weapon.

http://tvtropes.org/pmwiki/pmwiki.php/Main/WeaponizedExhaust

The Kzinti Lesson, had to be said.

[shynung]

It would also be practically useless.

The only targets in space are satellites in earth orbit. ASAT missiles or missiles on other satellites are enough to destroy them. If that thing came close enough to fire at them then a simple ASAT missile could destroy it in return.

There are things that an ASAT missile cannot reach easily: anything with a solid defense.

Current crop of ASAT are for things like spy satellites which doesn't have any kind of defense system, and has very little armor for them to defend with; adding armor makes it heavier, and in spacecrafts, every gram counts.

However, suppose you have something up there that is literally worth waging war upon, say a really big asteroid with high concentrations of rare elements, or maybe a space station dedicated to some top-secret stuff that can't be done on Earth for some reason.

Bringing in armor would be just as difficult as the spy-sat, since reasonably-tough armor plates are quite heavy. It's also, unlike the satellites, cannot simply be launched en masse, hoping that at least a few survives; space stations and/or asteroids takes a lot of energy to deploy (in the case of asteroids, either deploying the machinery to them, or deploying tugs that move them to the machinery). In short, only a few of these things can exist, due to cost constraints. So what would a defending general do?

Similar to how today's ships have less armor that WWII battleships, but just as difficult, of not more, to hit: Close-In Weapon Systems. Basically, stick a few quick-firing autocannons or pulsed laser emitters mounted on a turret, designed to shoot down any incoming projectiles and/or ships that comes within range. Trying to get through this kind of defense would require either lasers, particle cannons, huge swarms of ASATs, or a big, armored space battleship, like the Orion example posted. The first two can be countered by ablative armor (can be made lighter than solid, anti-kinetic armor) and ship-generated magnetic fields (strength depends of available power, only works against charged particles, neutral particles are unaffected), respectively, while the latter two are quite expensive in terms of material.

Basically, if there's something worth defending in space that can't be easily replaced, it would probably have CIWS. These are the tough nuts that are too unlikely to be destroyed by a simple ASAT.

[More Boosters]

I see no reason for missiles to exist in the context of space combat; or any kind of ballistic weaponry when lasers and other energy weapons strike the target with (almost) zero delay. Lasers get an even bigger advantage in that there is no atmosphere to drastically reduce their power in space, and nuclear weapons that aren't shaped to strike in one direction won't do much with no atmosphere to push around anyway.

Projectiles at relativistic velocities would also make sense as I would expect space combat to be all about range and precision where response time is the deciding factor.

As for ships, well, how many giant aircraft do you see? The reason ships are so large is that they float over water which is a very generous medium in that it allows good movement (water-based motors are more efficient as you'd note), a strategic advantage due to its placement but also the buoyant force that allows you to go nuts with anything as long as you watch your density. Space is a lot more similar to air than it is to seas where spacecraft are at the mercy of the rocket equation (which generally favors smaller craft) and are in far bigger trouble in case of hull breach. With that in mind, I'd foresee small fighters; perhaps unmanned, equipped with powerful laser weaponry or others that can engage at long range with very little delay.

If however the ubiquitous energy shields are somehow developed in the real world then maybe we could see other sorts of weaponry but I can't foresee anything that would manage not being shot down while somehow compensating for not being practically instant in its response.

[Halsfury]

Hi I'm a newcomer to this thread but I'm interested, I really think that the way it will probably work is at long range with little attention to close in combat which will be rendered fairly obsolete by virtue of the distances involved. Also the speeds involved make a crewed vehicle very slow to maneuver.

Kinetic weapons, such as ordinary cordite powered shells or smaller flak cannons, or even Railguns will probably be very limited in terms of their viability. This is due to every action having an equal and opposite reaction. If you were to use such a weapon it would have to be a very small percentage of the mass of the whole ship since said ship would have to use engine thrust to re-establish its orbit (or fire a projectile in the direction of the inverse vector which is generally not ideal).

Plasma weapons could also count as kinetic, just with far smaller masses but I digress since plasma is probably not a very good weapon choice since it needs an elaborate containment field, plasma is however a very useful byproduct of some types of explosions from a military standpoint.

*Don't know why I brought that up maybe Halo?

Anyway. The best weapon choices seem to be high energy lasers, which are very safe and cheap from an ordinance point of view, and missiles, since they generate no recoil and are known to be particularly devastating virtually everywhere they are applied, even underwater.

https://en.wikipedia.org/wiki/VA-111_Shkval

Missiles would be interesting, especially with the futuristic propulsion assigned to them such as an antimatter rocket drive, this would make them unable to rely on light, IR or radar tracking modes since the waves of these would stop making any sense to a missile guidance system. Also by this point, a payload is a worthless addition since the atoms of the missile would fuse with those of the target generating an atomic explosion.

Moreover the target vessel would be unable to avoid beyond visual range, because sensors would detect the missile's signature basically at the moment of impact since the missile is moving so fast that the light waves (including radar etc.) which would have warned the targeted ship would be bundled up essentially together with the missile since the missile is moving at only slightly less than the same rate.

Also this kind of missile is going to keep on going for ever, and it may, at some point hit something you didn't intend to hit and when it does it will fuse with that thing causing a high yield explosion, so the insurance company at the end of the universe will be thoroughly unhappy with you. But the plus side will be (if you can call it a plus) that you can shell a planet from 1000AU out with devastating consequences and merely wait 6 to 8 days (depending on the rocket's speed) for shell delivery to target, and you will only need maybe 15 of these to un-terraform an earth sized planet (yikes!).

Also since it has no effective guidance beyond it's initial launch it's more like a naval artillery shell in its use.

So all things considered for ship to ship combat lasers win out for being able to hit pinpoint locations on a ship at high speed in a cost effective manner, and provided the warship can predict it's opponent's orbit, it is able to do so from extreme range such as across 10-20 AU depending on just how futuristic and how large a weapon. This kind of battle would take hours, but it's doable since at theses kinds of ranges you would have to take into account relativity as well as your opponent's speed. I see the possibility for ships to target one another first with passive systems such as a radio-telescope fine tuned to detect ships and then for sighting the target for laser fire 3 telescopes could be used, then finally onboard computers could generate a firing solution for pinpoint accuracy using the 3 telescopes to trigonometrically deduce target location, heading, speed and distance. Then it could determine the time lag from relativity as well as gravitational distortion and aim the laser accordingly.

High sub luminal rockets would be less effective due to expense, also they would produce harmful radiation and high speed space junk, yet they would be very useful for planet bombardment. Also depending on how fast they accelerate they could prove worthless in ship to ship combat.

Slow hydrogen and oxygen powered missiles could be very useful close in (within a few hundred km) where a laser just wouldn't do. And finally old fashioned bullets and shells could be useful within 20km for things like repelling boarding actions. However they would be few and far between, with lasers point defence is really just a holdover anyway, such antiquated weapons would probably be kept only by merchant ships, where point defence against boarding actions is the main concern.

Edited September 7, 2015 by Halsfury

[Jouni]

A few ideas:

• Space is big. The distance where lasers are effective is by definition short range. Combat may happen over much longer distances.
  
• Stealth may be possible beyond short range. Think tiny probes with passive sensors and low-power electronics, using cold gas thrusters for course corrections before reaching short range.
  
• Offense is about joules while defense is about watts. Multiple waves of projectiles may arrive at the same time, possibly overwhelming target's defenses.
  
• Nukes may be cheap enough that every kinetic projectile can also be a nuclear warhead.
  

[tater]

Tiny, quiet/dim probes are be definition not maneuvering enough to matter (if at long ranges). Again, you need to nail down the universe. What kind of total dv do ships typically have? Is a quiet probe a threat if it takes 10+ years to reach the target area?

[Frozen_Heart]

Space is big. The distance where lasers are effective is by definition short range. Combat may happen over much longer distances.

wut.

lasers are by far the longest range weapon we have which is still practical. Yes a missile can technically go further but you'll see it coming a day in advance and change your velocity by the tiniest amount.

[Halsfury]

Perhaps a fighting space ship should be like a tank. Having one or two very high yield laser weapons. And other than that being very small, maybe with a crew of 20.

The setup should be almost like an observatory, basically a featureless tube with engines on the one end a few crew decks arranged perpendicularly, and finally the weapon and targeting gear at the top.

smaller sensors, RCS thrusters and point defence weapons mounts should gird the tube part.

The engine should have high enough delta V to thrust continuously to give the impression of gravity in transit and the whole thing should be designed to face it's target frontally like a tank during combat with the front being heavily armoured with ceramic composites and things which won't melt easily under the barrage of laser fire.

Basically it should look like an upscaled apollo capsule with an observatory like thing instead of a crew module. The radar telescopic sensors to detect the enemy ship should be scattered around the ship and be very redundant, gear to visually acquire your opponent for precise targeting would be basically a few telescopes which have a link to a fire control computer so it can do trig calculations on the target.

Yeah it wouldn't be super awesome or cool looking sadly.

Edited September 7, 2015 by Halsfury

[More Boosters]

Perhaps a fighting space ship should be like a tank. Having one or two very high yield laser weapons. And other than that being very small, maybe with a crew of 20.

The setup should be almost like an observatory, basically a featureless tube with engines on the one end a few crew decks arranged perpendicularly, and finally the weapon and targeting gear at the top.

smaller sensors, RCS thrusters and point defence weapons mounts should gird the tube part.

The engine should have high enough delta V to thrust continuously to give the impression of gravity in transit and the whole thing should be designed to face it's target frontally like a tank during combat with the front being heavily armoured with ceramic composites and things which won't melt easily under the barrage of laser fire.

Basically it should look like an upscaled apollo capsule with an observatory like thing instead of a crew module.

I still vote for unmanned probes equipped with an oversized (for their size) laser cannon, launched in dozens from a central assembly carried to the orbit by a rocket.

[Halsfury]

wut.

lasers are by far the longest range weapon we have which is still practical. Yes a missile can technically go further but you'll see it coming a day in advance and change your velocity by the tiniest amount.

Agreed, missiles entail throwing away a perfectly good fusion or antimatter drive which sounds like a lot of money wasted and though low risk for collateral damage due to the vastness of space it does sound dangerous, the only way it might work is to program the missile to explode releasing as much bird shot as it can carry over a wide area in space. This makes a hit far more likely, and with bird shot going at 80% of light speed or so each one is probably completely fatal, still you might as well try and hit a dime with a shotgun over 300 yards.

- - - Updated - - -

I still vote for unmanned probes equipped with an oversized (for their size) laser cannon, launched in dozens from a central assembly carried to the orbit by a rocket.

With the main gun, bigger is better, but in space, probes have limitations, there will need to be a manned craft within 1 or 2 light seconds of each probe or the probe is not going to have the reaction time to fight.

More remote ability is better though I do agree. Usually with the military, a vehicle and the people who operate it are equally expensive (due to training etc.) drones have reduced the cost tenfold or more for aircraft by virtue of not needing to support a pilot. Fighting space drones would be no different.

Also they can assist targeting for the mothership and each other and be much smaller, carry no expensive armour and rely on the mothership to deploy them deep into space.

Edited September 7, 2015 by Halsfury

[Jouni]

Tiny, quiet/dim probes are be definition not maneuvering enough to matter (if at long ranges). Again, you need to nail down the universe. What kind of total dv do ships typically have? Is a quiet probe a threat if it takes 10+ years to reach the target area?

I'm not assuming any particular setting. I'm just considering things that could work in one setting or another.

Maybe a ship fires a bunch of tiny probes from behind the planet / from behind a moon / from the orbit of another planet / from the middle of nowhere. The probes spend a lot of delta-v in a place, where the target can't see them very well. The probes enter stealth mode, using a negligible amount of delta-v for course corrections. Then, just before entering the estimated detection range, the probes activate whatever high-powered devices they carry. If everything went right, the target sees a bunch of probes appearing out of nowhere and firing at it from every direction.

That's the purpose of stealth: to take the initiative and to give the enemy less time to react.

As for the time required to reach target, tactical timeframe in modern warfare is typically from days to weeks. Operative level is from weeks to months, while strategic level is from months to years. Depending on what you're trying to achieve, a travel time of several years can be justified.

lasers are by far the longest range weapon we have which is still practical. Yes a missile can technically go further but you'll see it coming a day in advance and change your velocity by the tiniest amount.

You're thinking this the wrong way.

Lasers are the obvious weapon. They're accurate and fairly effective, and they hit the target almost instantly. If you don't want to have the enemy constantly firing at you with its lasers, you have to keep your distance.

The next question is whether you can do anything useful from that distance. If you spend a few hundred billion for R&D, you can probably answer the question.

[More Boosters]

You're thinking this the wrong way.

Lasers are the obvious weapon. They're accurate and fairly effective, and they hit the target almost instantly. If you don't want to have the enemy constantly firing at you with its lasers, you have to keep your distance.

The next question is whether you can do anything useful from that distance. If you spend a few hundred billion for R&D, you can probably answer the question.

I've read this a few times and I still don't see the point.

Are you talking about ranges where the laser beam (pretty focused) would be scattered? If yes, those ranges are ridiculous on the order of another system. (Granted you'd lose most of your impact well within the Solar System)

You (should) have your own lasers, assuming equal effectiveness on both sides, there's not much of a reason to stay away. If your enemy is using missiles and you're using lasers, keeping away is actually bad for them as they increase their own reaction time while not changing yours by much, so you really need to clarify your point here unless you're talking about FTL weapons in those few hundred billion for R&D.

[tater]

You presume to know where the enemy detectors are by saying "behind a moon." In a SF universe where people/beings are fighting with each other, they'd then put sensor satellites all over the place. You're behind a moon? So is their sensor.

[baggers]

Maybe we should pick up a scenario or 2:

Like:

- "invasion: from a planetary system to another"

- Or "war between 2 planets in the same planetary system"

- Or "war between 2 factions for ressource control in a third planetary system"

This could go in differents ways.

[Jouni]

I've read this a few times and I still don't see the point.

It's the most basic rule of fighting at any level: you always want to have an unfair advantage in a fight. Fair fights are for the stupid and the desperate.

Are you talking about ranges where the laser beam (pretty focused) would be scattered? If yes, those ranges are ridiculous on the order of another system. (Granted you'd lose most of your impact well within the Solar System)

I've understood that the effective range of laser weapons is closer to thousands of kilometers than to millions of kilometers, unless the beam is extremely wide or the wavelength is extremely short.

You (should) have your own lasers, assuming equal effectiveness on both sides, there's not much of a reason to stay away. If your enemy is using missiles and you're using lasers, keeping away is actually bad for them as they increase their own reaction time while not changing yours by much, so you really need to clarify your point here unless you're talking about FTL weapons in those few hundred billion for R&D.

If the enemy has lasers, you don't want to close to laser range, unless you already have an unfair advantage. Open fighting is the least useful thing you can do in a battle. It's much more useful to fight the enemy in a way that it can't fight back effectively.

Attack with superior numbers, and the enemy is torn to pieces before it can inflict serious damage to you. Use lasers that have a longer effective range than enemy lasers. Launch drones to fire at the enemy, while your ship is safely away. Swarm the enemy with so many missiles/drones/projectiles that it can't shoot down everything before they hit it. Blind enemy sensors or misdirect them. Hide a bomb in a resupply ship. Attack enemy supply lines. Hack enemy systems and let the enemy fight itself. There are countless of ideas that could work. What actually does work at what doesn't depends on the specific technologies and products in use.

[More Boosters]

Use lasers that have a longer effective range than enemy lasers.What actually does work at what doesn't depends on the specific technologies and products in use.

Oh so you'll have a better chance if your equipment is better? Because that has nothing in particular to do with this situation and everything to do with just about everything. Of course you should always try to avoid a fair fight, but that is about tactics and it has nothing to do with the speculative military applications of the science we either currently have or are close to.

What I'm trying to get at is that moving away from the enemy isn't specific to lasers; it's not a limitation of laser technology as it is a tactic adequate for the purely hypothetical situation you didn't share with us earlier. Not sure if it's viable to discuss such a specific what-if as your point can be applied to everything and such points usually don't carry the discussion further.

[Jouni]

You presume to know where the enemy detectors are by saying "behind a moon." In a SF universe where people/beings are fighting with each other, they'd then put sensor satellites all over the place. You're behind a moon? So is their sensor.

Placing sensors where they are needed is a similar problem as hitting the enemy with long-range weapons. The sensors can stay hidden as long as they remain silent. As soon as they become active, they can be detected and destroyed.

[tater]

You can detect at extreme ranges if the enemy is maneuvering at all. Dead quiet, you can detect them at merely large ranges. All weapons have effectively quite short ranges. Decently long range might be x-ray lasers.