Maybe create a new base defence system. It would be pricey, but would also be great for defence. The parts would be wired together with redstone, or some sort of ‘data cable’.
Sensors–these have a range of 200-300 blocks and detect ships being piloted by enemies nearby. They consume a fair amount of power and there can be more than one per set-up, but again, they use power. Perhaps a limit of four or so.
SAMs–these use 3k power per shot and have a cool down of 15 seconds each. They deal extreme damage, with a range of 300 blocks each. There can be a couple of these per set-up and can only fire at ships which sensors have detected–and are in range of both the sensors and SAM.
Core Computers–This is what controls everything. It consumes a moderate amount of power and is rather expensive. There could be different tiers, each with different limits for how many parts per set-up maybe. By right-clicking the sign it would open a GUI allowing you to turn it on and off, set whitelists (for players).
Again, these would have to be wired together with some sort of cable to work. If a part or section of wire blows up, the system wouldn’t work anymore unless there are backup cables/parts. Basically, there needs to be at least one of each part to keep working–an exception is the core computer, which, if destroyed, renders the system useless no matter what. It would be ideal to guard said computer.