The best shape for Massive ships

[Imperial528]

Star Wars Tech? Then what are we doing even bothering with weapons and armor, can't you just slap the largest hyperdrive ever on it, load it to the brim with people, supplies, and all the other things you need for a generational ship, and just slip away?

Although if you worry about being stopped, and this is a 100km diameter/length ship, you should have ample area for weapons, shields, and armor out the wazoo. And with SW tech, I don't really think you need to worry about the shape of it, it's made out of materials strong enough to resists gigaton-level blasts, there's no way in hell its own weight will tear it apart. Really, for shape just go with Rule Of Cool, or something that looks structurally sound enough to exist without power, since with SW-level technology, shape is a matter of preference rather than concern.

[Chaotic Neutral]

Just give it a rotary Eclipse superlaser with however many it takes to get a RoF of 1 per second.

[Batman]

Mang did anyone read my last post? I said this was a StarWars tech Civ, you have that to work with

Problem is, with Star Wars level tech, real world physics concerns largely cease to matter and vehicle shape essentially becomes a matter of personal preference, not technological considerations.

[Crossroads Inc.]

Ah very true sir :/ And I do want to try and ground this in reality as much as possible. Very valid point.
So far I am think "guild ship" but a bit more conical for weapons placement.

[Simon_Jester]

@Simon_Jester: I mean that each brick of ERA has a coating that would reflect/refract/otherwise neutral a laser pulse hitting it that contains an equal amount of energy as a kinetic projectile that a single brick of ERA would effectively protect against.
Although if we're talking high-speed as in hyper-velocity, then I'd just go with thick layers of, well, anything that's dense and cheaply produced in large quantities to be effective.

I don't think it's realistic to design things this way, really. ERA doesn't come with a label saying "defeats projectile carrying X joules of energy."

[Imperial528]

I know, but I was trying to tie the two concepts together in the best way I could.

[jollyreaper]

Mang didi anyone read my last post? I said this was a StarWars tech Civ, you have that to work with

I read that after my post.

Ftl like warp drive, jump drive, or stl like the Rama ship? That would really have bearing on the flavor of your ship.

A jump ship, for example, needs little strength. It just pops through wherever it goes. The only physical stress would be station-keeping drives that push it from spacedock, maybe some better drives if it has to match velocity with the target planet after jump.

But an stl generation ship could also be weaker of it had slow accelleration like taking years to hit cruising speed.

So, how star wars tech is it?

[Sea Skimmer]

You don't want ERA against lasers, or I wouldn't think you would. Ideally, you want something that will vaporize into a fogbank, which temporarily disperses the beam and limits its effect. Or something that's extremely difficult to burn off and rotating (spinning the ship helps; firing maneuvering thrusters randomly can help more in my opinion).

A Smoke/dust screen works; generating one in space with no air would be annoying but very possible. The bigger the ship the better it would work since you have less surface area vs. total mass. The best countermeasure will be to destroy the enemy laser optics with your own laser weapons. That should be much easier to do then the enemy punching a hole in your hull via a thermal-melting reaction. Assuming we don't have magic energy shields to change everything. Dust grenades fired into the laser path should also work; you'll be able to see the laser beam with optics of a suitable wavelength and have an automatic computer program by the year 2300 or whatever that can target the beam. Lasers are thus likely to be more attritional then crippling first salvo kind of weapons with both sides constantly presenting a fresh side while changing protective covers on the optics on the other, or something like that.

"Armor" that explodes into the path of an oncoming projectile is a specialized counter to a specialized type of threads. I'm really not sure it would translate well into space combat at all, though there are people I respect who believe it would.

By the time anyone can build major space warships I dare say reactive armor will have evolved into something that actually ejects from the ship prior to intercept. This has been discussed before and I've become fond of the idea vs normal reactive armor or highly advanced interceptor missiles. That way it can become very effective spaced armor and you can gain overlapping area coverage by having the tiles maneuver slightly. This would not require guidance, as we have no wind or rain ect.. to worry about. The trajectory could be controlled and fixed simply by firing a series of small ejection rockets in a specific sequence to tailor direction of the impulse.

I don't think you'd see much if any explosive reactive use, that's falling out of favor in some places even today, but reactive armor can work a lot of other ways, many of which can be successfully stacked on each other. A fairly simple layer of rubber can do a lot; higher energy impacts could exploit the deformation characteristics of proportionally denser metals. Even modern DU tank armor could be considered partly reactive, it reportedly is intended to deform. As a dead simple example of rubber, this appliqué armor on German PzH2000s has rubble bristles to simply make enemy cluster bombs hit and detonate at an unfavorable angle, increasing effective thickness just like sloped armor would. A damn lot is possible, all the more so if we have battleship torpedo defense system like volume to play with.


This armor was designed to stop DPICM and cluster bomblets, but now used to protect the vehicles roofs against direct hits by mortar bombs and lighter caliber rockets in Afghanistan.

[Purple]

What about foam? I read that the Russians planed to use foam as a countermeasure to laser guided projectiles since foam is easier to put up and stays put even in wind and rain since it is more dense.

Now, wind and rain are not considerations here but a foam cover could be dense enough to stick to the ship rather than dissipating and hence act as a shield against lasers.

[Crossroads Inc.]

Well shoot now I am planning on two Massive spaceships... Original one using "Magic Tech" from Starwars, super shields, armor, engines etc.
But now one utilizing much of the more 'reality' based ideas that have been floated. largely as they are MUCH more interesting then the magic tech stuff!

[Simon_Jester]

A Smoke/dust screen works; generating one in space with no air would be annoying but very possible. The bigger the ship the better it would work since you have less surface area vs. total mass. The best countermeasure will be to destroy the enemy laser optics with your own laser weapons. That should be much easier to do then the enemy punching a hole in your hull via a thermal-melting reaction. Assuming we don't have magic energy shields to change everything. Dust grenades fired into the laser path should also work; you'll be able to see the laser beam with optics of a suitable wavelength and have an automatic computer program by the year 2300 or whatever that can target the beam. Lasers are thus likely to be more attritional then crippling first salvo kind of weapons with both sides constantly presenting a fresh side while changing protective covers on the optics on the other, or something like that.

Well, there's the practical challenge of targeting at range. Just finding meter-scale objects on a hundred-meter or thousand-meter target isn't going to be easy when said target is thousands of kilometers away. So doing component shots may not be entirely practical, especially against a maneuvering target that can generate at least small uncertainty in where your laser fire is going to land on the target.

I'd expect a lot of ship to ship fire in space combat to be "throw it at that blip on the radar" rather than "target their weapon systems."

By the time anyone can build major space warships I dare say reactive armor will have evolved into something that actually ejects from the ship prior to intercept. This has been discussed before and I've become fond of the idea vs normal reactive armor or highly advanced interceptor missiles.

Ah. So... I'm trying to visualize the attack profile of these tiles. Should I be thinking of them as a sort of Bouncing Betty-equivalent* that lobs a cloud of gas/dust/plasma/flak/whatever into the path of incoming fire?

*Not necessarily exactly like a Bouncing Betty, since you don't want it to jump up and throw stuff at right angles to its line of flight, but sort of similar in the sense of 'an explosive device that launches itself and then detonates, throwing things in the direction of what you want dead.'

A damn lot is possible, all the more so if we have battleship torpedo defense system like volume to play with.

Oh yes, I very much agree. You're going to see a lot of interesting work done with armor geometry, along with armor composition, especially as we get into soft-SF levels of power and material science.

[Sea Skimmer]

Well, there's the practical challenge of targeting at range. Just finding meter-scale objects on a hundred-meter or thousand-meter target isn't going to be easy when said target is thousands of kilometers away. So doing component shots may not be entirely practical, especially against a maneuvering target that can generate at
least small uncertainty in where your laser fire is going to land on the target.

If the enemy laser is firing it will be glowing as a bright hot spot on the enemy hull. If the enemy laser lenses is even unmasked it will also make a very distinct reflective flare if you shine your own laser on it. This is how some of those new sniper locating devices work. The enemy could put decoy on his hull, but you should still be able to damage them all fairly quickly. Ruin the surface of a high power laser and the lenses will overheat and break very quickly, likely leading to a revolver cylinder kind of system to keep putting out new covers. I mean, really, this is stuff we are already worried about in real life already. You’ll find advice in army field manuals to tape over as much of your optics as you can to provide protection against laser damage. Its just western world attempts to ignore laser weapons and kept the subject quite.

Anyway, any inaccuracy YOU suffer with counter fire will also affect the enemy fire in the first place, denying his laser a concentrated dwell on the target. So all else being equal blinding out somewhat easily damaged laser optics ought to be easier then burning a hole clear through the hull. It might require sweeping the enemy hull with many means, but I can’t see it being impossible or ineffective if the enemy can damage you at all.

I'd expect a lot of ship to ship fire in space combat to be "throw it at that blip on the radar" rather than "target their weapon systems."

It would depend in part on how quickly you can close the range and just how fast you can actually get going; Orion and Ion engines could hit 10% of the speed of light on paper IIRC. So even at 1/10th top speed, 1% of the speed of light you are moving about 3,000km/s, that’s a pretty serious rate of closure you could have going. Just how high laser power levels can be, and how many of those we can afford to cluster on a single turret, is also a huge variable.

Ah. So... I'm trying to visualize the attack profile of these tiles. Should I be thinking of them as a sort of Bouncing Betty-equivalent* that lobs a cloud of gas/dust/plasma/flak/whatever into the path of incoming fire?

Yeah a bouncing betty is similar in concept, unguided projectile launched off to burst at a preset time. The Russian Drozd active protection system basically works the same way, so does Arena but Drozd is closer because it shoots projectiles directly at the incoming RPG or missile. But both Drozd and Arena only cover limited arcs, while I’m imagining that a fair portion of the surface of the ship would be covered with these things and that each one would have a slight ability to aim. Fire control would be via centralized sensors, the tile itself is dumb once the ejection charges fire. Controlling trajectory via explosions is BTW a proven principal. It’s just never been terribly practical because of reliability problems with producing numerous tiny explosive charges. I figure future tech can solve that.

The tiles would also as replaceable appliqué armor against lasers. In fact it might be possible that we could find a material or composite which would easily vaporize into a gas cloud to disrupt laser beams for the tiles surface, while also having the density and hardness to shatter incoming kinetic strikes once launched off. Though I figure if a kinetic projectile is fast enough it won’t really matter what it hits, contact with anything solid will produce vaporization.

[sirocco]

Anyway, any inaccuracy YOU suffer with counter fire will also affect the enemy fire in the first place, denying his laser a concentrated dwell on the target. So all else being equal blinding out somewhat easily damaged laser optics ought to be easier then burning a hole clear through the hull. It might require sweeping the enemy hull with many means, but I can’t see it being impossible or ineffective if the enemy can damage you at all.

From what I understood of the original post, the aim is to build ship able to cross the void between our galaxy and the next habitable one. So wouldn't you encounter alien civilization who took a radically different tech path?

He just needs to have a computer able to crunch the numbers faster and he can aim at your ship far better than you'd do.

[Sea Skimmer]

From what I understood of the original post, the aim is to build ship able to cross the void between our galaxy and the next habitable one. So wouldn't you encounter alien civilization who took a radically different tech path?

You might, but if physics holds true for everyone in the universe and we aren't crossing unverises then certain things will just work better then others. Humanity has proven pretty good at making weapons and personally I'm just trying to think up the most effective stuff possible. The threat could be anything, we want a ship which can handle everything we can dream, not any specific alien technology set. A whole enemy galaxy is likely to have a great diversity of technology anyway, so tailoring the mega ship to any highly specific threat is a bad idea. I'm not trying to say I think lasers would be the only weapon or anything, but the inherent advantages of speed and accuracy pretty much force them to be a major weapon, if only for blinding purposes. The only weapon that would be clearly superior for long range would be an FTL missile. As much as possible on the ship would be modular to facilitate repair and upgrades.

He just needs to have a computer able to crunch the numbers faster and he can aim at your ship far better than you'd do.

Number crunching cannot change the inherent accuracy of a weapon and after a certain high point prediction of target location would become perfect. Further increases in processing speed would mean nothing. We could well encounter superior alien technology for whatever reason, but that will just point to our own need to constantly improve our weapons. Nothing new about that in warfare.

[mdiinican]

With the materials available in the foreseeable future, the best way to build a 100km long ship might be to have it actually be 100km wide, with the engines all along on one of the narrower faces. Sort of like the homeworld mothership. Building it in a more traditional shape would be akin to building a 100km tall skyscraper on top of the engines, in gravity equivalent to the acceleration of the engine. That sounds difficult. Regardless of shape, the thing sure isn't going to be turning around very quickly.

[Sea Skimmer]

That would be kind of similar to the disk idea I was musing before. The only real problem with a very wide short ship, same one with the disk, is it won’t have a great deal of rigidity as one dimension is so much greater then the others. That’s okay cruising along when the engines can carefully balance thrust; but in combat it could become a liability. So various external braces of structure may be required.

[Imperial528]

With the materials available in the foreseeable future, the best way to build a 100km long ship might be to have it actually be 100km wide, with the engines all along on one of the narrower faces. Sort of like the homeworld mothership. Building it in a more traditional shape would be akin to building a 100km tall skyscraper on top of the engines, in gravity equivalent to the acceleration of the engine. That sounds difficult. Regardless of shape, the thing sure isn't going to be turning around very quickly.

Why not build the ship so that the engines at the front are the drive engines? Then you can brace it for tension forces instead of compression, which is much easier (especially if you use carbon nanotubes to tether it together internally). I think the ISV in Avatar works on the same concept. When it comes to turning, the ships should stay pretty structurally sound so long as it is flexible enough and you don't turn fast enough to generate any significant g forces from the end(s) swinging about.

[Purple]

A wild guess might be that it is because you are introducing a single and quite obvious weak point in the form of the cables?
I mean, that is fine for a non combat ship but once people start shooting at you the design starts loosing its cool.

[Imperial528]

That's why I was thinking that you have the cables be the internal structure core of it, in order to shoot them, an aggressor would have to go through the rest of the ship. At which point, you've otherwise lost if you've let them cut that far in.

[Sea Skimmer]

You could also use many overlapping lengths of cable in each run; then the loss of any one section isn’t critical.

[avatarxprime]

Well shoot now I am planning on two Massive spaceships... Original one using "Magic Tech" from Starwars, super shields, armor, engines etc.
But now one utilizing much of the more 'reality' based ideas that have been floated. largely as they are MUCH more interesting then the magic tech stuff!

Well if you want some more "reality based" tech for your ship, you could use a highly advanced thermoelectric generator in the ship to convert the bulk of your ship's waste heat into electrical power, vastly reducing the need for radiators. Current state of the art is ~15% waste heat recovery IIRC. Your sufficiently advanced civilization could maybe have achieved say 75+ percent. I'm afraid I don't know the theoretical maximum efficiency of such a system so the number is really just made up. Then there are metamaterials which have all kinds of fun properties. You could make your ship invisible to certain kinds of EM radiation, create all kinds of optical systems that simply aren't possible with actual lenses, there are a ton of possibilities there. Right now we can only manipulate light with long wavelengths, like infrared, and only in 2 dimensions, but I haven't read anything other than positive news regarding building visual light cloaks that work in 3 dimensions (just way in the future) with our current tech being the only limitation.

[Sarevok]

^^

I am afraid the electricity you produce from waste heat conversion would again become waste heat. That is ignoring the fact that thermocouple junctions are hideously inadequate. They suffice as heat detection elements for various sensor equipment and producing minute amounts of power for long endurance observation posts or satellites. But they are not good for "cloaking" a ship in the IR part of the spectrum.

[mdiinican]

Well shoot now I am planning on two Massive spaceships... Original one using "Magic Tech" from Starwars, super shields, armor, engines etc.
But now one utilizing much of the more 'reality' based ideas that have been floated. largely as they are MUCH more interesting then the magic tech stuff!

Well if you want some more "reality based" tech for your ship, you could use a highly advanced thermoelectric generator in the ship to convert the bulk of your ship's waste heat into electrical power, vastly reducing the need for radiators. Current state of the art is ~15% waste heat recovery IIRC. Your sufficiently advanced civilization could maybe have achieved say 75+ percent. I'm afraid I don't know the theoretical maximum efficiency of such a system so the number is really just made up. Then there are metamaterials which have all kinds of fun properties. You could make your ship invisible to certain kinds of EM radiation, create all kinds of optical systems that simply aren't possible with actual lenses, there are a ton of possibilities there. Right now we can only manipulate light with long wavelengths, like infrared, and only in 2 dimensions, but I haven't read anything other than positive news regarding building visual light cloaks that work in 3 dimensions (just way in the future) with our current tech being the only limitation.

Unfortunately, the efficiency of such a thermocouple or similar device is limited by the Carnot cycle efficiency for heat engines. Because it is essentially a kind of heat engine. The theoretical maximum is 1 - the temperature of the cold reservoir/the temperature of the hot reservoir. Thermocouples and things like stirling engines do not create electricity from heat per se. They create electricity from a heat gradient. The bigger the difference between the hot side and the cold side, the more efficient they can be. The device itself doesn't help at all at keeping the cold side cold. In space, using a thermocouple would pretty much entail sticking one side on what needs to be cooled, and the other side on a big friggin' radiator and radiating as much heat as possible as fast as possible. In order to be efficient, a heat engine has to move as much heat as possible from somewhere hot to somewhere cold. This is not conductive for stealth.

[Sarevok]

To be fair there is a difference between being found and being tracked. It is very difficult to find an object the size of a typical wet navy warship in space. We at present have not even cataloged the majority of asteroids over 300 m that entails the NEO moniker. Detecting previously unknown astronomical objects is a painstakingly slow process. A warship in powered down state could stay hidden for months or years right near an enemy homeworld. It would take some lucky optical sensor system looking at the right spot in space at the right time to find it.

On the other hand once a ship is detected there is no escaping tracking. Even present ground based telescope operating under Earth's prohibitive atmosphere can follow tiny moons and asteroids across the solar system.

So in short better not to invest much in stealthing because the chances of initial detection is low. But once detected meaningful evasion is almost impossible. So better gear up for the fight instead.

[Sarevok]

The difficulty of detection means there'll be difficulty in tracking too. If you move and they aren't sure just how you moved, being lost is a possibility.

Only if the enemy is stupid enough to treat a warship like an inert rock that does not change velocity. Tracking a warship 24/7 is not a problem at all even with present day telescopes.

Being found may be physically impossible too depending on a number of factors. If you keep your emissions low, it is very hard to be seen. (I know there's some fucktards on this site who think you can see things without photons triggering your receptors, but those people are fucking retards.)

Yeah instant detection of a shuttle sized object half way across the solar system, like some believe, is stupid. But at that range space combat is not possible. At ranges where realistic weapons work you are not sneaking up at all.

Of course, your emissions aren't necessarily under your control... the enemy might have big honking space radars, or the bloody sun might be lighting you right up.

Radar would kick ass within a few thousand kilometers. But beyond that ? I reckon optical and IR search and tracking would be better.