to my point of view, i see 6 type of defenses that can be mounted on a spaceship:
1) "force field" shield class
2) "barrier" shield class
3) "hull" armor class
4) "wall" armor class
5) "interception" system class
6) "deception" system class
NB: the "forcefield" and "barrier" shield class are both first line of defense but, due to the fact that they use the same technology but on two different way, they can hardly be used at the same time.
explanation of each type of defense :
1) "force field" shield class : that shield generate an outward force to counter projectiles.
- depending on the strengh of the "forcefield" it could slow, stop or deflect a projectile(plasma, missile or any other projectiles).
- this shield can be pierced by laser as laser are not projectile based weaponry.
- explosive or "energy based" projectile could alter the shield integrity (by adding sufficient force) for a moment allowing other weaponry to pierce it and damage the generator.
nb: it use two or more generators that create and modulate energy wave in a way so all waves are "high" were the shield would be erected.
2) "barrier" shield class: that shield generate an outward and an inward force to keep some material at a given distance of the ship. serving as a wall (or barrier) between you and the enemy, explaining the name.
- this shield is "medium dependent" which mean that it's effectiveness depend on the type of material you use as medium and it's caracteristic like maximum density, energy charge and viscosity (or aptitude to rapidly fill holes made in the barrier).
- this shield class is better in resilience than the "force field" class as it add like a second hull to your ship, acting like "spaced armour". that "second hull" could stop most of the enemy attack but, due to it's own nature, would also block your own attack.
- this shield class is bad for fighting in atmosphere or in nebulae because other materials would mix with the medium and could reduce it's effectiveness.
nb: this shield clas is quite expensive as each time you deploy it you use some material and when you deactivate the shield you can hardly recover the material you used.
for example: the defense of the
"Iserlohn forteress" in "legend of the galactic heroes" is a barrier class.
3) "hull" armor class: any type of defence that is attached on the hull.
there is little to say about it because everybody got a clear a view of what it is.
but sub class could be:
- reactive armor : all armored used to reduce the damage on impact. could be explosive-based (against kinetic), magnetic-based (against explosive) or energy-based (against plasma and ion)
- spaced armor : armor layer used to distort a projectile so that inner armor layer would suffer less damage. it's good againt thermal and magnetic (cannot reach the inner armor layer) , average against explosive, plasma and projectile.
- monobloc armor: armor where the thickness is the only advantage. it can block attack that dont have enough "penetration power".
4) "wall" armor class: armor that increase the defense of a specific room from the inside.
those armor could be:
- insulation: against fire propagation (could be useful that the incendiary weaponry dontstart a fire that can reach the fuel tank because if it overheat it could explode.)
- reinforced wall: to avoid or reduce hull breach propagation. (also avoid boarder cutting through the wall when they cant cut through the door.)
- maintenance wall : contain room enough for a technician to crawl in. could be default wall when the supply grid is going in a "wall" section, would be a weak spot so you would need to put the supply grid in place that dont need extra armor.
- ...
5) "interception" system class : any system that can be used to intercept an incoming attack and/or reduce it's potential.
that could include:
- AA turret (or anything that can shoot down incoming attack)
- drones (that could either shoot down incoming missiles (or planes) or be put in the path of an incoming attack.)
- depth charge (from "gundam Seed"): a capsule of material that have opposite charge than the main energy-based weapon and therefore negate some "energy-based" attack before being neutralized.
- ...
6) "deception" system class: any system that can be used to throw the enemy out of aim.
that could include:
- decoy system (against guided weapon like missile)
- jamming system (to make the enemy unable to scan your ship and lock it's weaponry on a specific part of your hull, like locking on cold part of the hull with higher probability to hit the cooling system)
- ...