Ultimately I expect a full-on interplanetary invasion just isn't possible without suborning a local faction or the threat and practice of orbital bombardment reprisals.
Or a sort of "conquest" that involves keeping half a continent away from any significant settlement.
@4WheelSword
IIRC gas giant fueling scoops and on-board refining were TL10 and built into hulls of that level - does this mean our 3rd generation ships are capable of self-refuelling? Or only the new-build hulls? Or only the newest ships like, I assume, the patrol carrier? Ta.
[X] Plan: Speak Softly
The comment on polity structure is a good one. I'd forgotten that a Homeworld-style mothership doctrine is entirely workable. That could be another reason to specialise in long-ranged ships, to operate out of unexpected backwater systems or take long detours around patrols.
That would make it even more likely that they'd have combat ships, though: the main difference would be more guns instead of fuel and endurance, and being reliant on vulnerable mobile infrastructure would make it even more important to have a face-melting brick to throw at attackers.
If they are doing the hegemony approach you suggest, that would suggest the reason for the distant raids is specifically to identify outsider states who might have enough firepower to flip the table. Though, doing your "scouting" in a way that would directly motivate such a power into coming over to throw you out an airlock seems counterproductive in comparison to making yourself look like too much trouble to bother contesting. Unless you believe in a Darwinian galaxy where any agency with the power to flatten its neighbour
will inevitably do that no matter what.
So you reckon they might have hit us in Menorb because otherwise, now that we knew the right questions to ask, the locals know too much to allow us to interact? Might also have been that that was the obvious next destination though - one planet might be a one off, two establishes a pattern, and then they concentrate to hit us in the next.
Another possibility might be that system in the West with the overdeveloped shipyards or another like them - after all, a system could be riddled with stealth ships and we wouldn't know at the time. That's another method - present yourself as just one more planet helpless in the grip of a shadowy enemy. But if Menorb is sky castles this is just rampant paranoia.
Though, come to think of it; looking at the map I'd thought Menorb was on the east side of those three northern systems, but if we assume the enemy is based north-northeast of us and north of the Aslan that would mean Menorb is especially distant from them, while if they're more north-northwest that would have visiting them more threatening as they're closer to home and more visited by the Aggressors. Unless they
are NNE and it's specifically
because Menorb is so distant that they visit it a lot for resupply...
2. - True, but I assume anyone in a prison will have some idea of who put them there and for what.
But given how ruthless the Aggressors are, if it
is their prison they might just have it set up to liquidate the prisoners if an intruder punches through the defence net.
4. - Would it work to build gun platforms as tiny asteroid stations, make them look like a bunch of rocks we dumped around to make it harder to spot our mines and fighters? Particularly in reference to your factory-refinery concept.
Sensor processing makes it vulnerable to jamming which is the natural response to a minefield but I guess the idea is that with something like this by the time you know you
should be jamming it there's already a half dozen gauss slugs addressed to you and in the mail.
6. - I'm generally not sure how survivable our fighters are. Smaller ones can deliver more ordnance and apparently laser fighters are effective if they can get in under point defence at extreme close range, but they seem fragile. But bigger fighters on a carrier mean you just end up with less targets... Maybe worth some more wargames? In any case a swarm of light drones seem like a good way to save a lot of costs. Maybe humans in strike craft might be better as something like sensor and electronic warfare shuttles? A more survivable force multiplier and local command role instead. No-one cries if a squadron of torpedo drones expends itself.
On the ship refit, sensor drones in particular seem like they'll be key, assuming they can spot through stealth. They'd also allow for the indirect torpedo attacks in orbitals that kept bring brought up around the time of the MMV.
Though cutting crew sizes might be bad for maintenance and endurance in the face of casualties. But building forward support would balance that.
Mobile resourcing, manufacturing and maintenance craft generally seem good to have. Would they be better as separate ships or a single mothership?
Or perhaps not even a ship at all - we could use the jump tug to move a station around, then send it out to fetch asteroids to feed the beast. Though that would add a bunch of points of failure that a unitary mothership wouldn't risk.
Interesting that the new FSS seems to have some of that capability, and it looks surprisingly cheap. Though given how fragile it is maybe there's a role for something more survivable that can give a fleet its own refuelling capability? Seems like it wouldn't have to be all that big. Unless that's gas giant refining capability rather than ice asteroid.