In episode 8, several mentions are made about the EDF having surfaced-based railguns for use in surface-to-orbit strikes along with surface-launched missiles. Are these railguns similar to the Aurora's quads, but scaled up to the size of the railguns used in the Lunar Gun Array? Are they deployed globally or only in strategic locations like the anti-spacecraft/aircraft plasma cannons that encircled Answari in episode 6?
The weren't really for surface to orbit, as it would be impossible to aim them at an object in orbit due to atmospheric friction and the Earth's gravity. Plus, you'd have to be able to accelerate the slugs to escape velocity and more, depending on the altitude of the target in orbit.
They were more like anti-aircraft weapons, used to protect surface to orbit missile sites from attack ships in the atmosphere.
I have read many descriptions of fixed fortifications being useless against mobile enemies. I have read all about the Maginot Line.
But still...
Fixed fortifications could take advantage of so many more advantages. Comparitively limitless power, because they don't have to drag the power source along. Nearly limitless ammunition because of the cheap availability of extra ammo bunkers.
It seems like a moon or ground based facility could spew hundreds of rounds in the general vicinity of a target, denying the use of the area to an adversary. If I targeted a location plus that at x+1 and x-1, and y+1 and y-1, it seems like I could pretty effectively deny access to the area.
Or am I just not getting the scale and scope here?
If your not moving your dead.
If you have a gun, I had a gun, both of us want the other dead and for some reason were wearing goggles that only show us what we would be looking at as it was five minutes ago. Would you want the bigger gun or the ability to side step?
Eric Nay: If I targeted a location plus that at x+1 and x-1, and y+1 and y-1, it seems like I could pretty effectively deny access to the area.
True, but you forgot to consider the units of those offsets. This results in issues due to the area that can be covered by each round VS the area where the enemy could be by the time the rounds get there. You can improve that somewhat by higher rate of fire and guided sub-munitions, but it's still a lot of area to cover.
Specifically, the units in this case is likely to be measured in miles/km rather than feet/yards/meters. If you figure each projectile is able to cover say a square meter, then you'd need millions of projectiles to effectively cover an area on the order of square kilometers (1 square km = 1 million square meters). Worst, the enemy will be traveling fairly quickly, so the denial area needs to be covered fairly quickly to ensure that the enemy is actually hit, since the enemy is only going to be in that area for a small amount of time, so you've probably got a second or less to cover the denial area with that many rounds.
So rather than spewing hundreds of rounds as you stated, practically speaking, you'd need to be spewing more like millions of rounds. You might be able to get that down some by using guided smart sub-munitions, but firing about 10-1000x as many rounds as suggested, per second.
surface area of the target affects how far apart the projectiles would have to be. I don't have to hit every square inch of the adversary ship, just enough of it to cause catastrophic damage.
True, relative velocity makes a huge impact, so to speak. Limited target size means the conical projection of attack vectors makes approach somewhat predictable, though.
I'm just noodling whether there is a case for fixed defenses around a planet, say. Lunar Base and asteroid bases, locations like that.
What kind of damage would it do to the environment / life in the area around the weapon site, the thunderous shockwaves of each individual round fired at speeds measured in % of light speed, and we would be talking about firing 100's of car sized projectiles a second. from numerous sites. I can see dead birds littering the ground for miles at the least. I would be fairly confident that sustained railgun fire of that magnitude could even change the weather in a localized area. It could result in tremors / minor earthquakes. If a city had a protective ring of Kenetic Turrets set up in a similar way to the Plasma Turrets we say on Takara, then the city would have no unbroken window/mirror/glass anything even before the enemy fired.
I would like to point out that because of the backlash in the form of shockwaves generated by the projectiles that there is a chance the initial fire from these weapons could disrupt or damage the guns / support systems for the guns / power networks, making sustained fire difficult.
I would think if the air defence rail guns were replaced (reestablished) they would use plasma versions instead at this point, and any larger guns intended to reach orbit would follow a similar model as the example on Takara, so using rail guns is moot point.
(#15 spoilers ahead)
The best planetary defence I can think of after reading 15 would be simple missile interceptors to shoot down incoming nuclear missiles and any fighters. These could be launched from either fixed locations or mobile vehicles dressed up to look like civilian buildings/vehicles from orbit so they can fire all their ordinance before being detected.
Next would involve more fighters and interceptors to extend beyond the coverage of the ground based defences, to provide air superiority and pick off incoming missiles from below the orbit of the ships bombarding the planet.
Now getting back to static defences, they really are sitting ducks to be quickly and easily destroyed from orbit with rail gun bombardment. I only see two options :
1) they are a big enough threat to deny enemy ships from parking in orbit in the first place or destroy them if they do. I can only think of one current Alliance tech to achieve this which would be launchers for surface to orbit jump missiles. Anything else (conventional/nuke missiles, Takara plasma turrerts) would require a stupid amount to be effect before being killed.
2) they are sufficiently capable of withstanding attack from orbit. I can't recall reading why there are no planet based shields. It seems like a no-brainer to put shields above key assets like military bases, defences, utilities, hospitals and major population centres. Powering them should be easier than it would be on a ship, and with more options available. I could see limitations in that the shields probably wouldn't be able to wrap around close to the ground, so you would have gaps parallel to the ground that shock waves and near misses could get under or when attacked at low angles from orbit, but as a defence against rail gun bombardment they should be an effective defence.
