Aerospace defence. It’s going to be a critical need for any spacegoing force.
You’re going to need defensive systems that operate on several different levels. Force shields if your universe has them, but also antisatellite weapons – lasers or the equivalent, missiles and so on, and of different sizes.
For energy weapons, there will be the massive ion cannons or heavy lasers that can bust through dreadnought-level armour, as well as smaller ones, right down to something like this.
I’m calling it the Archer-class; a seven-barreled mobile aerospace defence cannon.
Having seven barrels might seem like overkill (or possibly stupid: why not just one gun that’s much bigger and more powerful?), but I’m thinking it would be like the early Gatling guns: the multiple barrels prevent overheating and allow more sustained fire.
Anyway, here it is. I also made a little tow-truck thing to pull it around.