Effective Combat Range in Space

[Simon_Jester]

Yes- and the same problem would arise if you tried to launch kinetic-impactor* attacks from long range. Someone could fairly easily stage a hyperjump into your path and crap out a minefield, or hyperjump into your path and throw missiles, or hyperjump into your path and start lasering your impactors from very close range. You wouldn't get functional immunity to the defender's weapons simply by being a long way away from those weapons.

*I hate the acronym KKV for some reason, it's not rational, but I don't use it.

[doom3607]

There's a reason I was asking, repeatedly, if people thought I should maybe switch to a more jump-point-esque system. And I already suggested that, as far as capital ship energy weps go, I'm thinking maybe some sort of gravity wave gun that they can build as a by-product of being able to build the FTL engine. Think a big kill-everything-in-the-line-of-fire gun. Unless that's completely insane.*

And simon, maybe you dislike the acronym KKV because it's painfully close to the acronym for a certain well-known group of racists in the USA?

*Then again, setting off a nuclear bomb in your barrel is arguably nuts. Doesn't stop Bolos.

[Purple]

If you really want your big ships than I suggest you go a different route.
First, get rid of the whole jump point idea since you don't really need it. Instead make it so that the FTL drives are large and/or expensive and consume absolutely huge amounts of energy that just can not be produced by small ships. That way you have an excuse to have big ships. As for getting them to be useful, make them frigate/cruiser carriers. Imagine the image of a warship jumping into somewhere around Jupiter and deploying a large fleet from it's bowels to fight the defending fleet while it lumbers its way slowly into targeting range to unleash the rain of death on the defenders.

That is my advice at least.

[doom3607]

Hmmm... I kinda like it, but I'd like more commentary on the idea before give up on massive battleships. They're just... cooler.

[Dwelf]

It doesn't really matter what it is but there needs to be some plausible reason that big ships are worth their cost in smaller ships. Jump points are probably one of the easist ways to do this. They are not the only way to do it but they probably violate disbelief less than some of the other options.

More guns than it's mass in smaller ships, maths says no.
Harder to hit than a fleet of smaller ships, again maths says no.
Tougher yes but probably not going to take proportionally more killing than a fleet.
Command and control maybe but may require some mental gymanstics to justify why it takes soo much space.
Communications probably not, tight beam lasers should render comms almost impossible to jam and we already have the tech

The real world analysis means that it is probably going to come down to the FTL to provide this reason for being. But here you get options your already violating the laws of physics so as long as it's interesting people will most likely be ok with it.
Jump points work ok depending on the exact jump mechanics you either use them for offence or defence of jump points.
A FTL drive that scales based on surface area not mass would give larger ships an advantage in that area.
FTL weapon systems of some type. The internal space could be devoted to large relatively fragile weapons that smaller ships don't have space for. FTL weapons might not even require a break in the armour.
Cost of the FTL system could make the fleet of smaller ships more expensive to build than a huge ship.

So should you use a jump point system to me probably it simplifies things somewhat. The question you need to answer though is does it make the story interesting?

[Simon_Jester]

And simon, maybe you dislike the acronym KKV because it's painfully close to the acronym for a certain well-known group of racists in the USA?

That's a matter of total indifference to me; why would I even care? I find it inelegant somehow.

[doom3607]

FTL weapons... well, I already suggested maybe big strategic bombardment pods that basically just went FTL, landed on top of the enemy, and fired off a swarm of nukes from point blank range. But personally, I honestly think "jump points" make more sense. Not in the network of them sense, more in the "you can only go FTL from and exit it within one of these areas" sense- you can still go from any one of them to any other one, but it still take the normal amount of time for a ~1000c flight, so no semi-Stargate warfare. I'm thinking with a radius of ~100 km, and they're directly in between any object over a certain mass and their primaries, at a point with a certain net gravitational field strength- I'm thinking whatever the field strength is about ten thousand kilometers from the surface of Earth is good. Anyone see any obvious and massive problems with that?

[Simon_Jester]

FTL weapons... well, I already suggested maybe big strategic bombardment pods that basically just went FTL, landed on top of the enemy, and fired off a swarm of nukes from point blank range. But personally, I honestly think "jump points" make more sense. Not in the network of them sense, more in the "you can only go FTL from and exit it within one of these areas" sense- you can still go from any one of them to any other one, but it still take the normal amount of time for a ~1000c flight, so no semi-Stargate warfare. I'm thinking with a radius of ~100 km, and they're directly in between any object over a certain mass and their primaries, at a point with a certain net gravitational field strength- I'm thinking whatever the field strength is about ten thousand kilometers from the surface of Earth is good. Anyone see any obvious and massive problems with that?

Mars doesn't have one?

[Dwelf]

FTL weapons... well, I already suggested maybe big strategic bombardment pods that basically just went FTL, landed on top of the enemy, and fired off a swarm of nukes from point blank range. But personally, I honestly think "jump points" make more sense. Not in the network of them sense, more in the "you can only go FTL from and exit it within one of these areas" sense- you can still go from any one of them to any other one, but it still take the normal amount of time for a ~1000c flight, so no semi-Stargate warfare. I'm thinking with a radius of ~100 km, and they're directly in between any object over a certain mass and their primaries, at a point with a certain net gravitational field strength- I'm thinking whatever the field strength is about ten thousand kilometers from the surface of Earth is good. Anyone see any obvious and massive problems with that?

Are you planning on reducing the fuel capacity of your ships as 10 000km is extremely close to the planet. As a comparison GPS satalites are ~20 000 km above the surface the moon is around 400 000 km from the surface. I think you probably want a few more orders of magnitude on that distance.

[doom3607]

Fine, a hundred thousand. And seriously, Mars at no point has a net field strength of the equivalent of being one hundred thousand kilometers from Earth? I'd imagine it would just be closer. Likewise, Jupiter's would be vastly farther...

[Simon_Jester]

You said "ten," not "one hundred" the first time around.

The distances points you need can be calculated, to a good first approximation, from Newton's Universal Law of Gravitation for the mass of the planets in question. You'd want the force on some hypothetical test mass at the jump point to be the same at all jump points.

[doom3607]

I know how to get the field strength- grade 11 physics may be useless for a lot of stuff, but they did at least teach us that.

And you're right, I changed it after the other guy reminded me that geosynchronus orbit is more than 20,000 km up.

[Sky Captain]

You could also make your FTL work in a way that it is not possible to jump close to a star, say no closer that orbit of Neptune for sun like star. Then huge ships within a fleet of smaller more general purpose ships would make sense because they could immediately after jump start to attack targets deep in system with their x ray lasers. Depending on whether ships approaching in FTL are detectable before they emerge first information about incoming attack could be a shine of x ray laser.

[GrandMasterTerwynn]

You could also make your FTL work in a way that it is not possible to jump close to a star, say no closer that orbit of Neptune for sun like star. Then huge ships within a fleet of smaller more general purpose ships would make sense because they could immediately after jump start to attack targets deep in system with their x ray lasers. Depending on whether ships approaching in FTL are detectable before they emerge first information about incoming attack could be a shine of x ray laser.

Hmm. If you have ships big enough to mount X-ray lasers, then a sufficiently well-to-do defender will have have them screening anything of real interest inside the system. Sure, if there are no early-warning platforms with FTL-coms, the first indication of an attack will be x-ray laser shine . . . but, you can armor the platforms heavier than you can armor the incoming battleships, the platforms will have much higher rates of fire than the incoming battleships (since you can stick them onto big heatsinks, like nickel-iron asteroids of adequate size,) they don't necessarily have to have large (or any) crews aboard them, and the platforms will have a longer engagement range than you do (since they will be pointing outward, and won't care so much about what might fall into the cone of x-rays and get soft-killed at very long ranges, whereas you're probably looking to hard-kill things and limit collateral damage.)

You might build huge battleships with several x-ray lasers aboard, so they might be able to engage the defense platforms at-range, and hopefully kill enough of them that your smaller ships don't all die horribly. Then you use the smaller ships to engage the soft targets deeper inside the system and hold you giant battleships back (a strategy which makes sense if your opponent's reinforcements are limited in the number of points they can emerge from FTL. That way, they become a kind of defense platform for you.) Unless, of course, you're the sort of dick who cackles with glee at the thought of depopulating your opponents' space habs with hard x-rays.

[Purple]

What if you simply went the Star Destroyer route?
You could have it so that your battleships are indeed not superior in terms of firepower to their equivalent cost/mass in smaller ships. But on the flip side the enlarged internal volume allows them to transport and safely deliver massive amounts of ground forces right into an enemy orbit with the enemy being unable to do anything about it. Also, add some wave motion gun like super-weapon and you have a working model.

[doom3607]

I already suggested a wave motion gun-ish super weapon. Nobody has commented on it. At all.

I also already said there are sensors that pick things up in FTL, several light years out.

Now, the invasion force idea makes a certain amount of sense... but then again, so does the warp point model.

I still want to avoid ultra-long-range laser potshots.

[Dwelf]

You can easilly avoid long range laser pot shots. No beam is going to be perfect how tight the beam is will dictate it's range. You can either run the numbers or just pick a distance that you are happy with as the practical range for beams. Considering the lowish accelerations you are looking at I sugges something relatively short so other weapon systems are viable.

[Purple]

I already suggested a wave motion gun-ish super weapon. Nobody has commented on it. At all.

I just did and confirmed you.

I also already said there are sensors that pick things up in FTL, several light years out.

That does not really mean anything thought.

Think of it this way, there are sensors right now that can pick up a car from 10 kilometers away. But what does that mean for the average defender? Absolutely nothing because it all depends on t he speed. Until you pin down the speeds at which your FTL flies we can't really judge if light years or even parsecs are required. After all, if your sensors can pick a ship up from 1ly away and it is flying 365C than the enemy has a whole day to prepare but if it is flying at about 8000C (Warp 9.99) he has less than a hour. Now with Star Wars speeds... Well you get the picture.

[someone_else]

The torpedo boat was just too small and too slow a platform, an eggshell armed with a sledgehammer- certainly not something capable of "maneuver warfare" except under the most perfect of conditions against opposition whose feet are nailed to the floor, which is a common assumption made by people who make a fetish of maneuver at the expense of actual firepower.

The torpedo boats were too fast to be targeted by the big guns and the torpedoes were devastating. They were the reason destroyers (small ships agile as torpedo boats and with weapons able to sink them) were invented. They were called "torpedo boat destroyer", then just "destroyer".

Besides, ever played Navyfield? They had to place rules on the max number of torpedoes you can carry, or a team of noobs could easily one-shot a Big Awesome Ship of a veteran with a torpedo barrage.

Someone could fairly easily stage a hyperjump into your path and crap out a minefield, or hyperjump into your path and throw missiles, or hyperjump into your path and start lasering your impactors from very close range.

For the first the solution is simply "hyperjump past the minefield while laughing". For the second it's irrelevant since you could have deployed anti-EKV missiles from the target and they would have worked just as well (do you like more EKV? that's the real-world acronym for the kinetic impactors). For the third it may work, but now your lasers are in the harm's way.

[Sky Captain]

You could also make your FTL work in a way that it is not possible to jump close to a star, say no closer that orbit of Neptune for sun like star. Then huge ships within a fleet of smaller more general purpose ships would make sense because they could immediately after jump start to attack targets deep in system with their x ray lasers. Depending on whether ships approaching in FTL are detectable before they emerge first information about incoming attack could be a shine of x ray laser.

Hmm. If you have ships big enough to mount X-ray lasers, then a sufficiently well-to-do defender will have have them screening anything of real interest inside the system. Sure, if there are no early-warning platforms with FTL-coms, the first indication of an attack will be x-ray laser shine . . . but, you can armor the platforms heavier than you can armor the incoming battleships, the platforms will have much higher rates of fire than the incoming battleships (since you can stick them onto big heatsinks, like nickel-iron asteroids of adequate size,) they don't necessarily have to have large (or any) crews aboard them, and the platforms will have a longer engagement range than you do (since they will be pointing outward, and won't care so much about what might fall into the cone of x-rays and get soft-killed at very long ranges, whereas you're probably looking to hard-kill things and limit collateral damage.)

If attacker fires from outside the FTL limit then he could fire for some time and then jump his ships few light minutes in some random direction before return fire from in system defense platforms reach him and resume firing on in system targets after jump and repeat. Alternatively he could order his ships to perform some random sublight maneuvers before return fire is expected to reach his position. It would be pretty hard to repeatedly hit something few km is size from light hours away that can be anywhere within 50 000 km or more. Best defence strategy probably would be to have a fleet somewhere in interstellar space (but not too far) where it can quickly respond an jump to engage the attacker at close range.

[GrandMasterTerwynn]

You could also make your FTL work in a way that it is not possible to jump close to a star, say no closer that orbit of Neptune for sun like star. Then huge ships within a fleet of smaller more general purpose ships would make sense because they could immediately after jump start to attack targets deep in system with their x ray lasers. Depending on whether ships approaching in FTL are detectable before they emerge first information about incoming attack could be a shine of x ray laser.

Hmm. If you have ships big enough to mount X-ray lasers, then a sufficiently well-to-do defender will have have them screening anything of real interest inside the system. Sure, if there are no early-warning platforms with FTL-coms, the first indication of an attack will be x-ray laser shine . . . but, you can armor the platforms heavier than you can armor the incoming battleships, the platforms will have much higher rates of fire than the incoming battleships (since you can stick them onto big heatsinks, like nickel-iron asteroids of adequate size,) they don't necessarily have to have large (or any) crews aboard them, and the platforms will have a longer engagement range than you do (since they will be pointing outward, and won't care so much about what might fall into the cone of x-rays and get soft-killed at very long ranges, whereas you're probably looking to hard-kill things and limit collateral damage.)

If attacker fires from outside the FTL limit then he could fire for some time and then jump his ships few light minutes in some random direction before return fire from in system defense platforms reach him and resume firing on in system targets after jump and repeat. Alternatively he could order his ships to perform some random sublight maneuvers before return fire is expected to reach his position. It would be pretty hard to repeatedly hit something few km is size from light hours away that can be anywhere within 50 000 km or more. Best defence strategy probably would be to have a fleet somewhere in interstellar space (but not too far) where it can quickly respond an jump to engage the attacker at close range.

If you're postulating that the minimum FTL limit is somewhere around the orbit of Neptune, then you're probably light-hours away from anything important. Even an X-ray FEL only has an effective (as in, able to cut holes into things) range of light-minutes. Your invaders would have to go deeper into the system, to hit targets without risking collateral damage. So, let's say you cruise into striking distance, open fire, and then turn around and pull back out of striking distance. Unless you've got stupendous acceleration, you're going to take a non-trivial amount of time to decelerate to zero and then accelerate out of range. And you'll only minimize the time you're in contact with the defense platforms if you're just slipping into soft-kill range; which the platforms will probably be much better-hardened against than you will (being able to bury the platform inside an asteroid. They could even power it remotely through solar arrays driving masers.) At which point, if your enemy has a screening force hanging out somewhere in the system's scattered disk or Oort cloud, they can just drop in behind you and force you to either take the scenic route to escape the system, or go through the screening force because they've located themselves on top of your least-time route to the system's FTL wall.

[GrandMasterTerwynn]

I already suggested a wave motion gun-ish super weapon. Nobody has commented on it. At all. :?:

An X-ray FEL is a superweapon. If you've got one, you've got a weapon that's ridiculously dangerous to anything within a light-hour of you that cares to stand still long enough for you to shoot a laser at it.

I also already said there are sensors that pick things up in FTL, several light years out.

What's the resolution of your sensor? Is it "well, see this pixel on my display? It means that there's a rogue planet the size of Jupiter somewhere inside a billion-billion cubic kilometer volume at the distance of Alpha Centauri" Or is more like "we'll be able to read the hull-number of that crate before much longer." These sorts of things matter. There is a very nifty thread on sensors here. A sensor will be limited in one (or more) of the following ways. It'll either be limited in the size of the 'bucket' used to collect whatever you're trying to sense. It could be limited by the resolution of the detector on the bottom of the bucket. Finally, it can be limited by how much data you can process from the detector within a reasonable timeframe.

Now, the invasion force idea makes a certain amount of sense... but then again, so does the warp point model.

I still want to avoid ultra-long-range laser potshots.

If you have FTL sensors, then you can (conceivably) see the laser being fired well before it gets to you. Of course, you'll have to know the positions of the defenders' assets beforehand, and have FTL sensors watching all the likely suspects.

[doom3607]

As I've said before, and repeatedly: FTL sensors pick up things going FTL. Nothing else. That's all they tell you- the location of any active FTL drive mapped onto the equivalent realspace location. They are completely and utterly blind to anything and everything in normal space and at STL velocties. They do, however, locate the object accurately to within the 1000 km jump accuracy limit. In other words- you will see a hazy sphere about a thousand kilometers across. In it, something is going faster than light. That is all.

And, same bit about before and repeatedly, FTL drives go at 1000c.

[someone_else]

In case you don't want to have motherfuckers use the FTL in combat, you can say that the drive needs some time (a day, week or month, whatever) to be ready for the next use? (and say they can jump at a relatively close distance from planets)

Or that it needs significant time to perform (days, weeks, months), it's the same basically.