SF-warship plausibility question. (Some Phlebotinum)

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SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-28 02:44am

The Phlebotinum that is relevant is this:
FTL communications
FTL communication (at 1800x the speed of light) is possible. Such communication capability is cheap enough, and small enough, to be placed in ship-to-ship missiles. In addition, the FTL communication technology has a bandwidth sufficient to transfer relevant information in a timely fashion. (e.g. Transferring sensor data will be limited by transmission time, not the amount of information that can be transferred)

This permits centralised control of ship-to-ship missiles (e.g. using the firing vessels's superior computing power and access to a shell of sensor drones to more accurately counter the enemy's ECM, re-targeting missiles that are en-route to a mission-killed target).

It also makes the use of drone platforms (e.g. looking behind a planet, getting more accurate sensor data on the 4 'warships' that are really 3 decoys and 1 warship) practical since the maximum effective engagement range is about 3 light minutes so the command/control loop is only a tenth of a second for one-directional communication.

FTL Travel
While possible, it is limited to a handful of stable 'jump points' in any given system. Interception and engagement is possibly only in normal space. Jump points are limited to/from two specific points in normal space. A FTL drive system has sufficient mass and power requirements to be impossible to mount in something smaller than a frigate (smallest viable warship, mainly used for mine sweeping, commerce raiding, and commerce protection).

As such, all combat will be limited to low fractions of c (e.g. .2 or less) in normal space. If an enemy 'retreats' through a mapped jump point, you know exactly where they went.

Null Fields
It is possible to generate a field capable of concealing a low radiating, low mass object (e.g. 10 metric tons or less) to the point it would be indistinguishable from cosmic dust. However, anything concealed by such a field would be blind, deaf, and dumb. As such, it is mostly used for passive mine fields (for mining mapped jump points), smuggling (concealing cargo from inspection teams), and infiltration (e.g. blowing up your own freighter in low orbit and dropping an agent in a 'drop pod' hidden by a null field).

Setting Note:
The civilisations involved are between a Type 2 and a Type 3 on the Kardashev scale. There are no notable alien civilisations.

All that being the case...does this seem reasonable? (Ya, this will never be 'hard' sci-fi)
Missile Cluster (Human Modern, 'Average')
Flight Time: 15 minutes
Speed: .2c
Rate of Fire: 300 every 15 minutes Range (about 10% or so every missile launch is destroyed by micrometeorites, cosmic dust impact at the wrong angle, etc.)
(1 missile every 3 seconds, just in volley-form to overwhelm point defense)

Effective Range: 53,962,642 km (3 light minutes)

Payload:
Bomb-pumped x & gamma-ray lasers
Effective range is .2 light seconds - 59,958 kilometers

Point Defence Laser Cluster (Human Modern, 'Average')
Effective Range: 1 light second
Rate of Fire: 32 shots per second
Accuracy: ~80% (Average over 4 shots, 40%, 80%, 100%, 100% respectively and is part of why non-contact warheads are preferred. Giving your enemy a chance to knock down an extra 32 missiles per laser cluster is not worth it.)

Counter Missile Cluster (Human Modern, 'Average')
Effective Range: 2.8 light minutes
Rate of Fire: 20 per minute (280 per offensive missile launch)
Accuracy: 50% (about 10% or so every missile launch is destroyed by micrometeorites, cosmic dust impact at the wrong angle, etc.)
(1 missile every 3 seconds, just in mini-volley form)

ECM
Highly effective. About 50% of missiles which reach Point Defence range will be suckered off by decoys. In addition, the average warship is capable of convincing military grade sensors it is anything from a frigate to a capital ship. Assuming, of course, the sensor drones are unable to get close enough (e.g. its easy to pull this off at 50 million kilometers and virtually impossible at 50 kilometers). Over time, logic combined with battle damage would break such an illusion as well. A capital ship can launch thousands of missiles per 'volley'. A frigate can only manage 300.

Ship Design and Tactics
Warships are tubular with an umbrella-esque head on one end. The 'head' is very, very heavily armoured and covered with point defense. Directly behind the 'head' is the primary radiator section (I'm leaning towards a droplet-esque radiator which runs up the back of the armored front and the drops are caught by a matching disc a fraction of the way down the hull). Behind the radiator section, is the missile launching clusters. The aft has the primary drive system and power plants.

Warships are capable of acceleration in the 5000 m/s to 10000 m/s range with a maximum speed of about .1c (Probably a bit more phlebotinum, to avoid killing the human beings crewing the ships). The top speed is due to shielding limitations. Missiles are capable of exceeding this speed since no one cares if 10% of their launch is destroyed by 'accidents' when it degrades the accuracy of the enemy's point defense to 50-80% in most circumstances when combined with ECM.

The standard 'tactic' is a screening formation of anti-missile/drone platforms ('Destroyers') masquerading as a capital ship (via ECM) and serving as the capital ship's screen. The capital ship, in turn, serves as the primary offensive platform as well as command & control. The goal being to 'sucker' the enemy into targeting the anti-missile platforms instead of the offensive platform (the 'capital ship'). So, you have about 10 destroyers per capital ship. If firepower is divided evenly, the odds of an equally-sized force successfully hurting the capital ship is near 0. So it becomes a game of attrition and luck.

I'm not seeing a reason to have more than 3 roles (or classes, for that matter) of warship. I'm also debating about combining the destroyers and capital ships into a single vessel but I suspect specialised vessels are likely to be more effective. The classes being frigates (commerce raiding, protection, optimised for speed & endurance), destroyers (screening elements, anti-missile/drone platforms), capital ship (command & control, primarily offence platform). Although, I may convert a 'capital ship' to something destroyer-sized instead of the larger version I have in mind.

Thoughts? Or am I just crazy?

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Melchior » 2010-06-28 09:21pm

Why humans on warships, given STL speed and FTL comms? The (impossible) conservation of momentum violating tech needed to let the crew survive would probably have significant impact on everything else. The armored head with realistic materials is just a bigger target.
Missiles seem to have physically suspect engine power, also.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-28 11:17pm

Melchior wrote:Why humans on warships, given STL speed and FTL comms?
No (realistic) communication system is immune to disruption or penetration. Other than the speed of communication, I wasn't tampering with that fact. The crew size is minimal (e.g. 3-6).
The (impossible) conservation of momentum violating tech needed to let the crew survive would probably have significant impact on everything else.
Maybe I'm better off going with purely cybernetic life a la GitS. Such bodies should survive at those speeds, then.
The armored head with realistic materials is just a bigger target.
Alright, then any ship is likely to be mission-killed by a couple solid missile hits. That's fine with me.
Missiles seem to have physically suspect engine power, also.
Would reducing it to .1c for the missiles and .05c for the ships to make it more 'plausible'? These are ship-launched missiles, so they'll be getting some boost from the launching mechanism and the ship's current momentum.

My main concern is avoiding people looking at it and going 'WTF?'.

Thanks for the feedback.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Mayabird » 2010-06-29 01:09am

Then just leave out the damn numbers in the story. Nobody will care if you leave out the boring fluff if the story is engaging. Characters are more important than nitpicky details about how fast the missiles fly. These sorts of numbers are only important for consistency in your own storytelling, and unless it has some purpose to the plot, nobody wants to hear a lecture about how fast the stuff moves and so on. Frankly, since it's your own story, you could do whatever the hell you want.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-29 01:10am

Mayabird wrote:Then just leave out the damn numbers in the story. Nobody will care if you leave out the boring fluff if the story is engaging. Characters are more important than nitpicky details about how fast the missiles fly. These sorts of numbers are only important for consistency in your own storytelling, and unless it has some purpose to the plot, nobody wants to hear a lecture about how fast the stuff moves and so on. Frankly, since it's your own story, you could do whatever the hell you want.
Heh, that consistency is the only reason I'm asking if it is vaguely plausible. :P

I doubt I'll ever mention them specifically.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Melchior » 2010-06-29 10:47am

ShadowOfMadness wrote:Maybe I'm better off going with purely cybernetic life a la GitS. Such bodies should survive at those speeds, then.
With extensive modifications it might be plausible; how advanced are expert systems/AIs?[/quote]
ShadowOfMadness wrote:Would reducing it to .1c for the missiles and .05c for the ships to make it more 'plausible'? These are ship-launched missiles, so they'll be getting some boost from the launching mechanism and the ship's current momentum.
How does the launching mecanism work? If they get a significant part of their accelaration from the launcher, the subsequent maneuverability might be limited. Have you settled on any particular drive mechanism?

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-29 11:21am

Melchior wrote:
ShadowOfMadness wrote:Maybe I'm better off going with purely cybernetic life a la GitS. Such bodies should survive at those speeds, then.
With extensive modifications it might be plausible; how advanced are expert systems/AIs?
[/quote]
I was planning to have AIs achieve near-sentience. (e.g. They can perform any set of tasks a human could, however they are limited to that set of tasks. So an AI designed to handle ship-board repairs to the drive system could only perform that one task.)

However, the 'people' getting swapped into cybernetic bodies would be fully functional people. (e.g. Sentient)

Basically, except for the 'bridge crew', the ships will rely heavily on automation with the exception of a single theocracy which considers AI that advanced 'unholy' and will use larger crews (but still automate heavily) because of it.
ShadowOfMadness wrote:Would reducing it to .1c for the missiles and .05c for the ships to make it more 'plausible'? These are ship-launched missiles, so they'll be getting some boost from the launching mechanism and the ship's current momentum.
How does the launching mecanism work? If they get a significant part of their accelaration from the launcher, the subsequent maneuverability might be limited. Have you settled on any particular drive mechanism?
I haven't decided tbh, I was figuring other than ranges, degree of accuracy, and rough ideas on the effectiveness/possibilities of ECM I wasn't going to need to be that precise for internal consistency. I wasn't planning to have any of the weapon crews serve as main characters (who might, logically, start discussing weapon functionality in detail). I was figuring being tossed out of a ship at half the missile's top speed plus some form of launching mechanism would get it about 75% of its top speed (top speed being defined as the point where increasing the effectiveness of the weapon is outweighed by the loss of missiles to micrometeorite and cosmic dust impacts due to the level of protection one can force into a missile). Ship top speed is the same.

Would that impart too much initial momentum to the missiles for 50 million km engagement ranges to be practical (e.g. the ships can dodge the missiles)?

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Connor MacLeod » 2010-06-29 01:15pm

Why do I keep thinking of a blend of david weber novels when I read the OP? It sounds so much like that.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Simon_Jester » 2010-06-29 01:40pm

I'm going to second Maya's comments. Fiddling the numbers won't make this setting more or less plausible; you don't make FTL communications more "plausible" by changing them from 1800c to 18000c or 180c. It doesn't matter.

This will do; it's not totally retarded or anything. Now to move to something that matters: characterization.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Mayabird » 2010-06-29 02:33pm

ShadowOfMadness wrote:
Mayabird wrote:Then just leave out the damn numbers in the story. Nobody will care if you leave out the boring fluff if the story is engaging. Characters are more important than nitpicky details about how fast the missiles fly. These sorts of numbers are only important for consistency in your own storytelling, and unless it has some purpose to the plot, nobody wants to hear a lecture about how fast the stuff moves and so on. Frankly, since it's your own story, you could do whatever the hell you want.
Heh, that consistency is the only reason I'm asking if it is vaguely plausible. :P
I went over this a couple times in my head, and I'm not sure if we're meaning the same thing when we say "consistency" so I'm going to clarify my position.

I mean, you need to know how fast your ships go. That number is arbitrary and irrelevant, but it has to be the same in the stories. If it takes one week to travel a certain distance and that distance is between Dyson Sphere 1 and Orbital Cloud 5, it should take one week to get between them. However, you shouldn't have people going four times that distance in three days because you got bored with it and decided to make it faster. If it takes two solid hits to destroy a warship, it should always take about two solid hits and the hero's ship shouldn't be able to take fifty just because you don't want him to die. That's what I mean. The rules have to be consistent in-universe and you need to know how they work, but the audience doesn't necessarily need to know and probably doesn't care to. The rules themselves can be whatever you want.

Also a note: it's often better not to explain it, because detailed explanations can open yourself up to saying something really stupid. It works and always works like this; nod and move on.


Now, are you asking about consistency as in you want the technology to be consistent with itself? Because you do know there's no such thing as 'technology levels' where everything fits into certain categories that all go together when you hit a certain point, right? It's not like, "If you can shoot missiles this fast then your mecha-exoskeleton-piloted-fighting suits have to be this tall and have this powerful a laser on it." If it all feels advanced enough and there aren't anachronisms that would knock us out of suspension of disbelief, good enough.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Sarevok » 2010-06-29 02:39pm

Honest question and not wanting to be a prick.

Has anyone ever read one of those so called stories that people claim to be write when asking for enough info dump to fill a moderately sized pop sci book ?
I have to tell you something everything I wrote above is a lie.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-29 11:04pm

Connor MacLeod wrote:Why do I keep thinking of a blend of david weber novels when I read the OP? It sounds so much like that.
The choice of missile combat being the primary form of space combat and the use of bomb pumped warheads?

Only thing I can think of.
Simon_Jester wrote:...

This will do; it's not totally retarded or anything. ...
That is mainly what I wanted to know. :P Although 'not totally retarded' was a bit lower than the bar I was aiming for :P

Sarevok wrote:Honest question and not wanting to be a prick.

Has anyone ever read one of those so called stories that people claim to be write when asking for enough info dump to fill a moderately sized pop sci book ?
Asking if something is plausible isn't the same as asking for an info dump.
Mayabird wrote:
ShadowOfMadness wrote:
Mayabird wrote:Then just leave out the damn numbers in the story. Nobody will care if you leave out the boring fluff if the story is engaging. Characters are more important than nitpicky details about how fast the missiles fly. These sorts of numbers are only important for consistency in your own storytelling, and unless it has some purpose to the plot, nobody wants to hear a lecture about how fast the stuff moves and so on. Frankly, since it's your own story, you could do whatever the hell you want.
Heh, that consistency is the only reason I'm asking if it is vaguely plausible. :P
I went over this a couple times in my head, and I'm not sure if we're meaning the same thing when we say "consistency" so I'm going to clarify my position.
...
I think you misunderstood me.

What I meant was basically:

If it consistently makes people go 'wtf?', it is a problem unless I wanted to re-write all the travel times, etc. part way through.

If it consistently makes people ignore it, that's fine.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Teleros » 2010-06-30 10:13am

None of it's making me go "WTF?" so I think you're safe on that point. It does look like combat will evolve much like it does in the Honor Harrington series though ("we need moar pods!!111!!"), and does seem fairly similar to that setting. Ship classes look interesting, although there may still be ways to check whether that destroyer really is one or not (a big telescope will help, for example :P ).

Oh, and don't forget that the only real speed limit for missiles & such will be the speed of light: the longer you can accelerate for, the higher your velocity will be at the end. Thus I'd be careful about both giving speed limits to things (as opposed to acceleration limits), and I'd also come up with a very rough calc for the chance of a missile hitting a micrometeorite per distance travelled, which would make more sense than a flat 10% figure. Eg in open space it might be 1% chance per missile per light-second, up to 10% chance when in the heavily-mined asteroid field, and then 50% when there's battlefield debris and radiation filling the area as well (these particular numbers are pulled out of my arse of course). Which reminds me - would this lead to better protected missiles or the use of other weapons, and if not why is it too expensive?

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-06-30 10:43pm

Teleros wrote:None of it's making me go "WTF?" so I think you're safe on that point. It does look like combat will evolve much like it does in the Honor Harrington series though ("we need moar pods!!111!!"), and does seem fairly similar to that setting.
There won't be any pods. Most of the impetus for missiles are coming from the ship and ship-based launching capability. There won't be any heavy energy weapons either, ships simply aren't going to be durable enough to survive into energy range.
Ship classes look interesting, although there may still be ways to check whether that destroyer really is one or not (a big telescope will help, for example :P ).
We have optical stealth capabilities now, if simple ones. I'd say that falls under the 'ECM' category. ;)
Oh, and don't forget that the only real speed limit for missiles & such will be the speed of light: the longer you can accelerate for, the higher your velocity will be at the end.
The main reason I give 'speed limits' is the armor and shielding on these vessels will start to fail above those speeds. At .1c, its pretty safe. At .2c, you are looking at about a 1% chance of being crippled per minute.
Thus I'd be careful about both giving speed limits to things (as opposed to acceleration limits), and I'd also come up with a very rough calc for the chance of a missile hitting a micrometeorite per distance travelled, which would make more sense than a flat 10% figure.
I was giving flat figures for simplicity's sake, honestly, I'd probably write a simple computer program to calculate point defense accuracy, counter missile accuracy, % destroyed due to micrometeorites and cosmic dust, etc.
Eg in open space it might be 1% chance per missile per light-second, up to 10% chance when in the heavily-mined asteroid field, and then 50% when there's battlefield debris and radiation filling the area as well (these particular numbers are pulled out of my arse of course).
That makes sense to me. I was just going to go with a base figure originally for simplicity's sake.
Which reminds me - would this lead to better protected missiles or the use of other weapons, and if not why is it too expensive?
The use of other weapons is mainly the range limitation and the soft targets these ships represent. There are not 'shields' or 'sidewalls' on these vessels. A single missile hit is going to be a serious problem, even for a ship with redundancy (e.g. warships). If you know any good weapons that have decent hit rates on a target 50 million km away, let me know. Missiles seemed the only ones that required little (if any) suspension of disbelief to accept.

The main thing is, their materials science isn't good enough to build complex systems the size of a warship capable of reaching .2c. Missiles run into a similar problem. The difference is, accepting the attrition per volley of missiles at .2c is made up for in the higher to-hit chance on a per-missile basis. (e.g. .15c missiles are less likely to hit than .2c, even counting the % lost due to micrometeorites, debris, and cosmic dust)

The reason 'warships' stop accelerating at .1c is the fact they run the risk of losing radiators and having holes punched in their hulls at higher speeds. Basically, the .1c is the 'safe limit' for their ability to armor their vessels. Some groups of humans will be able to hit .11c (.22c for missiles), etc.

Thanks for the feedback. :)

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Melchior » 2010-07-01 11:18am

ShadowOfMadness wrote: The reason 'warships' stop accelerating at .1c is the fact they run the risk of losing radiators and having holes punched in their hulls at higher speeds. Basically, the .1c is the 'safe limit' for their ability to armor their vessels. Some groups of humans will be able to hit .11c (.22c for missiles), etc.
I suspect that if a ship can survive a rock at 0.1 c, nuclear weapons and bomb pumped lasers aren't going to do much without the ability to specifically target minute weakpoints (also it's probably impossibile for anything of reasonable thickness to resist that kind of impact).

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-07-04 06:51pm

Melchior wrote:
ShadowOfMadness wrote: The reason 'warships' stop accelerating at .1c is the fact they run the risk of losing radiators and having holes punched in their hulls at higher speeds. Basically, the .1c is the 'safe limit' for their ability to armor their vessels. Some groups of humans will be able to hit .11c (.22c for missiles), etc.
I suspect that if a ship can survive a rock at 0.1 c, nuclear weapons and bomb pumped lasers aren't going to do much without the ability to specifically target minute weakpoints (also it's probably impossibile for anything of reasonable thickness to resist that kind of impact).

A very, very small rock (1 gram or less) at .1c. I suppose I can just come with a phlebotinum material if it is really that odd/unlikely.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Sea Skimmer » 2010-07-05 04:15pm

The trouble is even with speeds much lower then .1c, anything remotely close to known materials are just going to vaporize on contact. Enough thickness of armor might hold against a very small rock, but it will have a heck of crater blown out of it and that will mean a massive shock wave is transmitted into the ship. You can't passively deal with that much energy.

But what you could with some plausibility would be able to do is have reactive armor which triggers just before its hit, and launches a metal plate out into the path of the rock. The rock and plate vaporize as before, but the plate is no longer attached to the ship, and thus the shock is not directly transmitted into the ship. The underlying armor would still be hit by a lot of heat and some vapor pressure, but it would be much more realistic for it to survive this without heavy damage. Whats more the reactive armor could be 'aimable' in that each plate doesn't just fire off in a fixed direction, it could be fired off by several rockets which give it some directional control. Basically the reactive armor becomes a crude and very short range guided missile. That way if one plate is hit and gone, the plates around it could fire off at angles to protect the 'hole' in the reactive armor. That way the enemy has to hit the same area many times before he can get a direct hit on the hull itself. This would greatly reduce the normal problem with reactive armor, which is in ability of any one plate to cope with more then one hit. It would also be very expensive... but this is a space warship so who cares how much it costs? A space warship will make a nuclear submarine look like a plastic toy in terms of cost per ton either way.

Now of course sufficient phlebotinum can solve all of this, you could have armor which wont vaporize and is super dense and undergoes deformation to absorb the energy if you want, but it would still be a serious pain the ass to deal with the shock. So I would suggest a combination of phlebotinum and reactive armor made out of the phlebotinum to give you that extra space to keep vaporization away from the hull.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-07-05 06:53pm

Sea Skimmer wrote:The trouble is even with speeds much lower then .1c, anything remotely close to known materials are just going to vaporize on contact. Enough thickness of armor might hold against a very small rock, but it will have a heck of crater blown out of it and that will mean a massive shock wave is transmitted into the ship. You can't passively deal with that much energy.
Alright. At that point, I'm likely to just decide the primary purpose of point defense (when travelling) is to destroy micrometeorites. Cosmic dust should be survivable with phlebotinum-based armor.

I'm likely to put reactive armor in place, if it'll increase survivability against bomb-pumped x & gamma ray lasers, since it would be 'stupid' of the ship's designers not to (assuming it would work). However, it is likely to be 'reloadable' (e.g. You have layer #1 on the hull, behind each location there is several more 'chunks' of reactive armor that can be pushed out to replace lost sections) simply because I can't think of a reason a sufficiently advanced civilisation couldn't build 'reloadable' reactive armor. But maybe I misunderstood and you meant it purely to stop micrometeroites.

The rocks were never intended to be 'weapons' since at the ranges we are talking about (50 million km), they would be evadable.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Sea Skimmer » 2010-07-05 10:46pm

ShadowOfMadness wrote: I'm likely to put reactive armor in place, if it'll increase survivability against bomb-pumped x & gamma ray lasers, since it would be 'stupid' of the ship's designers not to (assuming it would work).
It can, the mass of the plate being vaporized by the X-ray laser would still work as armor and tend to disrupt the beam, though its not likely to work any differently then passive armor. One option for defending from laser and radiation weapons is to simply wrap the entire ship in its own fuel and propellent tanks. That way all that mass also acts as armoring like the torpedo defense system on warships make use of the ships fuel too. Using many small tanks would limit how much fuel you loose from a hit, though at some cost in total capacity for fuel. I figure that should matter, because you can always get refueled by another ship even if you have to drift a long time waiting for resupply. If the enemy weapon blows the guts of the ship apart, it hardly matters that you have lots of fuel leftover.

However, it is likely to be 'reloadable' (e.g. You have layer #1 on the hull, behind each location there is several more 'chunks' of reactive armor that can be pushed out to replace lost sections) simply because I can't think of a reason a sufficiently advanced civilisation couldn't build 'reloadable' reactive armor. But maybe I misunderstood and you meant it purely to stop micrometeroites.

The rocks were never intended to be 'weapons' since at the ranges we are talking about (50 million km), they would be evadable.
I just assumed it was a surrogate for any type of kinetic energy hit. Reloading reactive armor sounds like more trouble then its worth. Layers of the tiles make sense for sure, but nothing would stop an inner layer from simply exploding in place. That would be way less complicated then making the armor move, which means you need thousands of motors to move each specific piece all of them shock hardened. Reactive armor tiles would be maybe a foot or two thick at most (though they can be anything you want really), so its not going to make much difference, and the rocket control system can aim the tile after it clears the extra foot of distance. Such reactive armor would not be triggered by impact, you'd have some kind of distributed sensor system to fire the plates just before impact in ordered to gain more stand off distance.

The ship can have storage for surplus tiles and some on board repair capacity, so you can send people out in space suits to replace tiles in-between battles.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-07-05 11:56pm

Sea Skimmer wrote:
ShadowOfMadness wrote: I'm likely to put reactive armor in place, if it'll increase survivability against bomb-pumped x & gamma ray lasers, since it would be 'stupid' of the ship's designers not to (assuming it would work).
It can, the mass of the plate being vaporized by the X-ray laser would still work as armor and tend to disrupt the beam, though its not likely to work any differently then passive armor. One option for defending from laser and radiation weapons is to simply wrap the entire ship in its own fuel and propellent tanks. That way all that mass also acts as armoring like the torpedo defense system on warships make use of the ships fuel too. Using many small tanks would limit how much fuel you loose from a hit, though at some cost in total capacity for fuel. I figure that should matter, because you can always get refueled by another ship even if you have to drift a long time waiting for resupply. If the enemy weapon blows the guts of the ship apart, it hardly matters that you have lots of fuel leftover.
That could be viable. I hadn't really decided on the type of fuel and propulsion. As long as it is something that won't react from a hit (e.g. cause secondary explosives) that makes sense. I'm starting to suspect my 'soft targets' are likely to be hard targets and I need to revise the way space-borne combat will work. Otherwise, they'll survive dozens of hits and my original assumptions will go out the window. (e.g. One side or the other will be wiped out by the time they enter 'dumb rock' or ship-mounted energy weapon ranges)

However, it is likely to be 'reloadable' (e.g. You have layer #1 on the hull, behind each location there is several more 'chunks' of reactive armor that can be pushed out to replace lost sections) simply because I can't think of a reason a sufficiently advanced civilisation couldn't build 'reloadable' reactive armor. But maybe I misunderstood and you meant it purely to stop micrometeroites.

The rocks were never intended to be 'weapons' since at the ranges we are talking about (50 million km), they would be evadable.
I just assumed it was a surrogate for any type of kinetic energy hit. Reloading reactive armor sounds like more trouble then its worth. Layers of the tiles make sense for sure, but nothing would stop an inner layer from simply exploding in place. That would be way less complicated then making the armor move, which means you need thousands of motors to move each specific piece all of them shock hardened. Reactive armor tiles would be maybe a foot or two thick at most (though they can be anything you want really), so its not going to make much difference, and the rocket control system can aim the tile after it clears the extra foot of distance. Such reactive armor would not be triggered by impact, you'd have some kind of distributed sensor system to fire the plates just before impact in ordered to gain more stand off distance.

The ship can have storage for surplus tiles and some on board repair capacity, so you can send people out in space suits to replace tiles in-between battles.
That makes sense. Unfortunately, I'm not planning for kinetic-energy type weapons to be a viable option. I expect the ships to be annihilated long before they get into 'dumb kinetic projectile' range.

_____________________________________________________________________________________________________________________________________

I think I'm going to have to make a 'new OP' at this point since there is a glaring flaw (soft targets are likely to be hard targets) now.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Sea Skimmer » 2010-07-06 12:47am

If ships can travel at a useful fraction of C then it would be hard to entirely avoid engagements which could get within missile range. Something to remember is that in space, unlike in the air or on water, you can't carry speed through a turn. A plane making a 180 degree turn away from a missile can retain most of its speed as it does so. But a space ship turning 180 degrees has to do an entire burn to bring itself to a halt, then accelerate back in the other direction. That means its a lot harder to evade a missile, because its harder and more time consuming to change course. The faster a ship goes, the longer an engine burn it will take to change course. Your own speed can become your worst enemy, unless you have completely massive engine power.

Those jump points you have also provide a chance for close range ambushes. The need to defend planets or fixed installations could also cause shorter range engagements then might otherwise occur. You also have the issue of the first hour of the war to consider. Ships of two sides might be quite close to each other when a war starts. It was common for Soviet destroyers to follow US carriers around just a few miles away for example in the Cold War. That way when war broke out the destroyer could fire torpedoes and missiles before anyone could react. This led to some very aggressive conduct between the escorts and the communists, and more then one collision. Such conduct could also occur in a space cold war.

Something worth considering is that in real life we've had missiles that can sink ships 250 miles over the horizon since the late 1950s, and yet to date an anti ship missile has never been fired over the horizon in combat (plenty of land attack missiles have been of course). Meanwhile quite a few ships have been sunk by 'obsolete' naval gunfire in the same period. Its not from a lack of capability, but rather just the lack of opportunity, but still 50 years is a long time and I doubt anyone would have predicted it!

Not every combat situation all will be the optimal scenario a ship was intended for. I do tend to agree that missiles (unless you have FTL missiles) will be only very limited weapons, because of how absurdly vast space. But then I also would not place any real faith in jamming in space for missile deflection. Jamming tends to exploit the clutter of the earths surface and the distortion of the air the help it function, and even then its really hard to make it work well anymore. In space you have this vast empty void around you, and a incoming missile is going to use more then one kind of guidance to track you which will allow it to filter out and home in on jamming. So ECM is more likely to take a form of a hard kill system, something like a high power microwave antenna that burns out the enemy guidance system, then conventional jamming. Such a microwave weapon could be very powerful if you designed it to use hundreds of small antennas spread across the entire hull of the ship. This would let have a far larger effective antenna size, allowing for better beam control and MORE POWER without having to mount some big clumsy microwave cannon antenna turret on the hull.

As an added bonus, the microwave weapon could be the same antenna and system that also serves as the ships space radar. You could make it even more powerful by towing additional antennas elements (and other sensors too) behind the ship like a towed array sonar. On paper if you had a good enough antenna control system (not out of reason for future technology, but you'd need major Phlebotinum software to make it work today) you could have this antenna be dozens of kilometers long and even function while it is curved or bent as you tow it through turns.
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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-07-06 02:04am

Sea Skimmer wrote:If ships can travel at a useful fraction of C then it would be hard to entirely avoid engagements which could get within missile range. Something to remember is that in space, unlike in the air or on water, you can't carry speed through a turn. A plane making a 180 degree turn away from a missile can retain most of its speed as it does so. But a space ship turning 180 degrees has to do an entire burn to bring itself to a halt, then accelerate back in the other direction. That means its a lot harder to evade a missile, because its harder and more time consuming to change course. The faster a ship goes, the longer an engine burn it will take to change course. Your own speed can become your worst enemy, unless you have completely massive engine power.
Sorry, I wasn't clear. I meant missile engagement range is likely to be the 'norm'. For that reason, if ships aren't easily killed by missiles ('soft targets'), it is likely to result in fleets getting into beam weapon (or even dumb rock!) range.
Those jump points you have also provide a chance for close range ambushes.
True...if you know which jump point they'll be using.
The need to defend planets or fixed installations could also cause shorter range engagements then might otherwise occur.
Fixed installations and planets are vulnerable to kinetic strikes at essentially 'infinite' range. So the only way 'fixed defenses' would be viable is guarding jump points imo.
You also have the issue of the first hour of the war to consider. Ships of two sides might be quite close to each other when a war starts. It was common for Soviet destroyers to follow US carriers around just a few miles away for example in the Cold War. That way when war broke out the destroyer could fire torpedoes and missiles before anyone could react. This led to some very aggressive conduct between the escorts and the communists, and more then one collision. Such conduct could also occur in a space cold war.
True...since the start of this is going to be closer to a multi-power 'cold war' than a hot war. Although I'm not certain about that point since the 'hot war' is likely to be 'more action'.

High risk games of chicken could be fun too. ;)
Something worth considering is that in real life we've had missiles that can sink ships 250 miles over the horizon since the late 1950s, and yet to date an anti ship missile has never been fired over the horizon in combat (plenty of land attack missiles have been of course).
True....but I doubt there will be a 'horizon' of that sort in space unless you are hiding behind a planet or something.
Meanwhile quite a few ships have been sunk by 'obsolete' naval gunfire in the same period. Its not from a lack of capability, but rather just the lack of opportunity, but still 50 years is a long time and I doubt anyone would have predicted it!
I'll keep that in mind....especially if missiles won't be the deciding factor in most engagements. Although in that case, I doubt it'll be 'obsolete'. I'm not going to intentionally cripple the intelligence of my ship designers.
Not every combat situation all will be the optimal scenario a ship was intended for. I do tend to agree that missiles (unless you have FTL missiles) will be only very limited weapons, because of how absurdly vast space.
I don't agree with the missile part unless there is a defense capable of making them less than decisive.
But then I also would not place any real faith in jamming in space for missile deflection. Jamming tends to exploit the clutter of the earths surface and the distortion of the air the help it function, and even then its really hard to make it work well anymore. In space you have this vast empty void around you, and a incoming missile is going to use more then one kind of guidance to track you which will allow it to filter out and home in on jamming. So ECM is more likely to take a form of a hard kill system, something like a high power microwave antenna that burns out the enemy guidance system, then conventional jamming. Such a microwave weapon could be very powerful if you designed it to use hundreds of small antennas spread across the entire hull of the ship. This would let have a far larger effective antenna size, allowing for better beam control and MORE POWER without having to mount some big clumsy microwave cannon antenna turret on the hull.
I wasn't planning to use 'jamming' per say. Rather a combination of optical camouflage, decoys, and the like. Although, a microwave antenna for anti-guidance may make sense to complement that (possibly replacing point defense to an extent).
As an added bonus, the microwave weapon could be the same antenna and system that also serves as the ships space radar. You could make it even more powerful by towing additional antennas elements (and other sensors too) behind the ship like a towed array sonar.
That could work. Although, I may have a dedicated 'sensor/command and control ship' at that point.
On paper if you had a good enough antenna control system (not out of reason for future technology, but you'd need major Phlebotinum software to make it work today) you could have this antenna be dozens of kilometers long and even function while it is curved or bent as you tow it through turns.
I think Phelbotinum-class software is a standard trope for this sort of thing. Thanks for the idea.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Melchior » 2010-07-06 07:15pm

If you introduce magic armor (besides reactive one) to deal with fast rocks, you'll probably need magical weapons too to penetrate it. Also, why doesn't everyone just heavily mine and focus fire on the few jump points in every relevant system, thus stopping any invasion force that doesn't spend hundreds of years in transit?

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by ShadowOfMadness » 2010-07-07 12:17pm

Melchior wrote:If you introduce magic armor (besides reactive one) to deal with fast rocks,
The rocks aren't moving. Its the ships that are (hence, the switching to a % PD to remove them from the path).
... Also, why doesn't everyone just heavily mine and focus fire on the few jump points in every relevant system, thus stopping any invasion force that doesn't spend hundreds of years in transit?
Mining 5 light minutes (in diameter) of space is likely to be highly resource intensive. Also, nothing stops the other guy from simply jumping in large rocks with engines (essentially) to soak up said mines. That doesn't consider the impact of mines on trade. When you can make a trip in less than a month between two points on a trade route...some things are going to be worth trading. Whether it is phlebotinum, information, luxury goods, or even some types of electronics.

I'm trying to work out the weapons, propulsion, etc. first since the story focuses (to some degree) on conflict between large political units capable of building and deploying interstellar-navies.

Like I said a few posts ago, I'm going to need to work out a new OP (or go with the 'People won't say WTF' degree of accuracy). Although, the torpedo defense is making me lean towards the former simply because I didn't think of it and it might turn missiles from 'decisive' to 'a way to soften the other guy up before finishing each other in energy and/or dumb rock range'.

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Re: SF-warship plausibility question. (Some Phlebotinum)

Post by Teleros » 2010-07-07 01:04pm

ShadowOfMadness wrote:
Melchior wrote:If you introduce magic armor (besides reactive one) to deal with fast rocks,
The rocks aren't moving. Its the ships that are (hence, the switching to a % PD to remove them from the path).
Technically, relative to the ship, the rocks are moving :P .
... Also, why doesn't everyone just heavily mine and focus fire on the few jump points in every relevant system, thus stopping any invasion force that doesn't spend hundreds of years in transit?
Mining 5 light minutes (in diameter) of space is likely to be highly resource intensive. Also, nothing stops the other guy from simply jumping in large rocks with engines (essentially) to soak up said mines. That doesn't consider the impact of mines on trade.[/quote]
You could however mine an area with bomb-pumped X-ray lasers (and big ones, as they won't need to be fired via missile). Enemy fleet exiting the jump point? Press the button. Enemy asteroids with engines on them? Let 'em pass the mines, we have FTL sensors / comms so we can track them easily, and mop them up later.

I suppose the most obvious response to this would be to spam the jump point you're about to attack with something designed to either destroy or disable the mines. Depending on distance between mines, big but otherwise regular nukes might do it (or at least punch a hole in the minefield). Defenders of course could respond with multiple layers of mines at the most likely exit routes, or minelayers designed to rapidly deploy new mines to plug any breaches.

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