Jonathan_S wrote:And without first hand evidence that the sensors do pick up the kinds of weapons used against Manticore and Grayson I don't think I'd be so complacent about leaving 3rd fleet (less some ready response BC squadrons) with cold nodes.
Keeping the nodes energised for months on end puts a severe wear on them, shortening their lifetimes. The ships may as well keep flying erratic and random courses to keep from being targeted by something that has to come in ballistically.
Or they can invest on detection. If they can have a sensor bubble 15 light-seconds in radius, that puts any penetration 4.5 million km away, which is far more than energy range (note: against unmoving targets, it should be enough, but I didn't make the rules; maybe they are using cold jets to do a random dance). If they are in the middle of fixed defences, then those defences should be able to shoot at anything coming at them. If detection of a weapon moving at 0.25c happens at 4.2 million km (14 light-seconds) away, CMs can intercept the weapons short of energy range. The CMs will need 34 seconds to surpass to get to ~750,000 km from the targets they're defending, while the weapons will have closed only 8.5 light-seconds, meaning they are still 2.5 light-seconds from the CMs and energy range.
The ships' impellers can't be brought up fast enough, but missiles' can. They can be used in barricade mode to interpose themselves between the detected bogey and the ships.
Note this has to happen anywhere a fleet is located, if it is not moving. The terminus is not an exclusive location where this is worse than anywhere else.
And that's doubly true around a Junction terminus with its relatively tiny hyper limit (less than a million km). An attacker with good astrogation, and a willingness to risk clipping the RZ (with the destruction that would entail) could drop out of hyper within missile range of the Junction and the fleet anchoring there. I don't care how good your sensors are when someone can pop out of hyper within a couple million km and have missiles hitting you in just a handful of minutes; long before any of the ships could get their wedges and sidewalls up. You better pray that the fixed defenses can confuse, kill, or, lacking, that soak up all those missiles or you'd lose a lot of hideously vulnerable ships. (Though the attacker likely wouldn't survive the counter battery fire)
Note: we're talking about the terminus on the Beowulf side, but as I said above, all places have the same problem, so the Junction counts too.
However, you're right that an attacker could simply arrive from alpha and fire at anything inside the volume of the Junction or terminus' hyperlimit. That is a mere light-second in radius, so anything inside that volume is within energy range of something that made their alpha translation close enough. And this doesn't need a spider drive or graser torpedo. Any ship's capital graser broadside could do the job. It is a suicide mission, though.
Anyway, just how do they defend against this?
Of course the Mycroft platforms defending the inner system wouldn't be inside the Junction's sensor bubble -- they're 362 LM from the primary -- but how about sensor bubbles of their own?
That was my question. Either they did not have sufficient sensor coverage, or that coverage wasn't sufficient to detect the Silver Bullets.
If it is the former, it might be that you can't have that many sensor platforms and remain stealthy. No one doubts where the terminus is and the location of the ships was obvious too. So having sufficient drones for the sensor coverage wouldn't be revealing anything anyone didn't yet know. But emplacing them around the Mycroft platforms could have.
Now there would likely be multiple shells of platforms, though the inner shell may, or may not, provide full coverage -- but you'd want enough that you'd have multiple redundant paths of relays between the planet(s) and the outer shell of platforms. Specifically so some malfunction, sabotage, or attack, can't easily cut the planets off from those.
I didn't get the impression they had more than a handful yet. I agree on the redundancy, but I don't think they'd achieved that goal.
However I don't know if any Mycroft platforms would be close enough to a planet to be inside its own sensor bubble (which is hopefully just as tight as the one around the Junction) -- though possibly at least one of the "master platforms" would be close enough to Beowulf to be within its sensor bubble (in which case, since they seem to have all gotten blown up, we'd have evidence that those sensors failed to detect the Silver Bullet(s) that killed those platforms).
Agreed, but we don't know that.
However, I don't think each of the outer shell of Mycroft platforms would sit within its own sensor bubble. That would either require covering the surface area of a ~20 LM sphere with sensors -- which would require a ludicrous number of sensor platforms -- or else providing a little pinprick sensor bubble around each Mycroft platform -- which would rather highlight where they are for any attacker trying to take them out. They're supposed to hide until needed -- sticking a bunch of radars and other active sensors around them rather defeats that.
Yup.