@Hoyr, can we get some more information on existing GARDIAN systems in your head?
Specifically, I'm thinking about range and arcs of fire. Unfortunately, the information we have is pretty limited: the only ground based installation I can think of is Horizon, and those systems are cinematic vs effective.
As TheEyes has pointed out, if the tower can aim below the 0 degree line, the only escape is outranging it or hiding behind the horizon (3km per meter off the ground or so). Do arc reactor powered towers have the 20km range needed? Can they aim that low?
Okay so arc of fire:
File:Airbornelaserturret.jpg - Wikipedia, the free encyclopedia
See that? It's what I call a ball turret, it how you should aim any laser you can spread enough to bounce before focusing it with a lens/mirror. It's arc of fire is effectively "yes" the only limitation is the object it's mounted on (and friendlies/terrain). I assume GARDIAN lasers use those. I don't usually assume spinal FEL lasers use them.
Range is one of those complicated question and I have pretty charts to give me some basic data on this. Key factors are wavelength, aiming lens/mirror radius, power at lens/mirror, pulse time/time on target and target material.
For a 200MW, 0.5m radius lens laser firing at 700nm with 0.01 second pulses. (My default GARDIAN laser) the range is ~10km (Carbon)-30km (Iron) for easy single pulse kills on fighters and tougher missiles. The weapon is still effective to a 105km range vs iron (40-60km for carbon) and falls into low levels of effect (mm per pulse) out to 345 km for iron (150-175km for carbon). AB armor and tungsten fall between carbon and iron. Hope that helps.
Arc-reactor powered lasers... well I'll assuming you mean 5GW 400nm lasers? Yes they have 20km range, they even turn the air in their way into plasma at that power level (IIRC) which makes the laser far worse... to get better lasers working in air you need variable wavelength lasers to do some fancy tricks so that the laser can get (most) of it's power though. Also using lower wavelengths (aka vacuum frequencies) so that the plasmafication of the air actually helps.
In space (SPACE!) that doesn't matter so range goes way up.
We never priced out our Improved Piliums, but for simplicity I'll use the same 20,000 credits apiece number that I used initially.
Huh... don't know why its 20,000cr... should closer to 25,000cr/0.05pr as three reloads costs 75,000cr/0.15pr to make. But yeah MK II eh same price.
But whatever, close enough. Reload casings cost 5,000 each for reasons I guess.
According to
@Hoyr a decent GARDIAN laser turret can take out 15,000 Sagitta-grade missiles in 4 seconds, so to be relatively certain of a kill we need 30,000 missiles, 5% of which (1,500) need to be our Improved Piliums to ensure a decent number both get through and do some actual damage.
Do note that was an upper bound based on material destruction. It'll probably be less than that.. by how much IDK. Though see note below.
So, that's our current cost to reliably blow up a GARDIAN tower that took 100 million credits to build.
I was thinking the 100m million is an anti-space craft laser at 200MW the one I was talking about was a weaker anti-ground laser at 20MW not sure if that should hold true, but that was the idea. Mind the cost scale isn't going to be linear, but it'll be cheaper for a 20MW. On the other hand the 200MW one has 10 times the destructive power.
I have to say that this number does not seem right. 0.0002666(6 repeating ) seconds to take out a missile? Or rather, 2 ten thousandths of a second to take down a sagitta?
Maybe if the missiles lined up single file. But I have doubts that it could take the stresses of turning fast enough to aim for each of them. Beyond which, it also has to determine if a sagitta is mission killed or not, which should take at least a little bit more time than that.
Firstly
upper bound estimate people aka "most possible at all".
But it does seem damn fast doesn't it? So some thoughts
Well first off RL computer base calculation times are in the nanoseconds, and ME things are as good or better... the computer isn't having trouble doing this... in fact it may very well by trying to optimize the aiming order. Bonus points if it has a quantum combination optimizer.
Determining kills is easy, look at item size (plus any other details you have) and determine how much power you need, note the target after hitting it and while shooting at the next if it's not dead shoot at it again. Yes there is inefficiency, but it'll get ironed out pretty fast.
As for turning? The targets start pretty far away the turning after the first snap to is pretty minimal in distance though the torque for rapid movement can still be quite high. But Mass Effect! You can drop the mass of the rotating part of the turret, vastly dropping needed torque to the point were it's like magic. And the materials retain their same strength! Sadly I am not an engineer and my friend that does that sort of thing is kinda busy with finals too... so I have no one to consult on the fun of rotational stress... I do know that mass is part of at least one formula.
Okay, okay I'm a sucker for math... fine I'll try, can't be that hard people only speed 4 years learning this stuff right? At a lazy approximation it looks like my guesstimate shaft can rotate 0.5 degrees in ~0.00044s from full start to full stop. 20km away a 0.5 degree rotation is ~175m, way to much but meh. If the kill time is 0.0002666... then it can kill ~1418.6 missiles per second. Mass effect just makes it
faster, a 100 fold reduction field (speed of light x10 field) can get the kill rate up to 3220 missiles per second. Hmm... dropping the target to target distance to 43m at 20km makes it ~2058 missiles without mass effect. Hint hint attacking from lots of angles is good.
Do note this massively ignores internals component stress tolerance... which would be a set of motors some lenses and a mirror. I don't feel like trying to figure that out without some one that knows more. Do recall that ME has inertial dampeners that can deal with a few million gees though; It's how FTL doesn't kill everyone.
And now I have a new set of formulas in my spreadsheet for this quest... oh boy. Please note that I barely know what I'm doing with the math and just took some basic formulas and plugged in numbers.
I'm not saying that those issue are totally gone, but they would seem to be fairly manageable. Of course the thing I pointed out was an upper bound (maybe even a little conservative I assumed Micro-missiles need to be ~1/4 melted to die after all), the idea was to find a a point they can do no better than, but worse is possible.
EDit: You know the less time I write these the more time I have to do finals and write the update...
Don't recall that being learned. Mordin just though a piece of tech that could access you brian via touch was creepy. Asari at least have the safety that they feel everything the person the meld with does the same way they do.