On AKVs and Survivability

From the questions box:

Dear Gentlesoph,
Having been reading your posts, I have a question about AKVs such as the ‘Daggerfan’ and ‘Slasher’ classes. With high-powered lasers capable of doing damage at one light second, how do AKVs survive the 300,000km journey into single kilometer range? As stated in your ‘Nonstandard Starship Scuffles’ post, military vessels use armor woven through with thermal superconductors dumping heat into ‘thermal goo’. I assume this armor/thermal management system applies to AKVs as well, although you also state that point-defense lasers will shred a vessel unfortunate enough to get into very close range. How can an AKV survive at single kilometer ranges long enough to inflict damage on the target? Thank you for your time, I look forward to more posts!

Well, there are two parts to this: how do AKVs close to skin-dancing range, and how do they survive when they get there? I’ll take ’em one at a time.

On the first point: with great difficulty.

If you take a wing of AKVs and throw them at a fresh battleship, all you’re doing is providing its point-defense computers with skeet; they’ll be chaff and charnel before they get anywhere near the inside of the BB’s point-defense zone.

What you have to do is wear it down first. That’s is the job of the non-carriers on your side of the fight: throw a lot of kinetics at the enemy to make their PD work hard. That does three jobs: one, it keeps the PD grid busy in itself; two, any of it that gets through may just take out a chunk of the PD grid; but most importantly, three, by making them run their point-defenses, you’re building up heat in their ship. Your non-carriers also have the job of pumping heat into their ship directly with the big lasers.

That heat, in turn, is going to eat away at their PD efficiency in a variety of ways. Most simply, it’s going to have to cut back on its firing rate once the heat sinks start filling, because otherwise the crew will cook, but also the hardware becomes less efficient, processor error rates go up, and similar badness ensues.

That’s when you send in the AKVs, and you send in a lot of AKVs mingled with a lot of chaff and decoys, swamping the capabilities of the now-degraded PD grid. They won’t all get through – you plan for a lot of them not to – but once the grid’s sufficiently degraded, enough will to ruin the BB’s day.

As for when they’re there? Remember, they’re described as operating within the point-defense envelope, which is to say, inside its inner boundary, which is defined by the minimum effective range of the PD – set by a variety of factors, such as the range at which firing the PD will seriously damage your own ship, but of which probably the most important is the ability of the PD to track the target and slew to fire on it. At the sort of hug-the-hull sub-km range AKVs like to operate at, it doesn’t take much velocity to generate a huge traversal angle, and what you can’t track, you can’t reliably hit.

(And it’s hard for your screen to fire effectively at the AKVs ruining your day, ’cause even discounting the effects of the AKV exploding at point-blank range, every miss will hit you.)

All of which is to say: While there are some subtleties and complexities to the tactics (defense AKVs, screening vessels sharing PD, etc., etc.), the short answer is it takes a lot of work and losses to get an AKV force within range of a target, but once you do, that target is dead meat.

Starship Scuffles: Location, Location, Location…

So, while it now seems to have disappeared from the Internet, my article on Non-Standard Starship Scuffles appears to have come in for some little criticism:

First, for having FTL in it; and

Second, for assuming that space battles will take place in open space, the commenter apparently not seeing any reason why they would ever take place except right next to whatever strategic nexus point they’re fighting over.

To a degree, on both points, I’m inclined to question the reading that gave rise to those comments because on the first, well, while there is mention of FTL communications with observation platforms to improve one’s longscan for tactical advantage, the ships themselves don’t – can’t – move at FTL speeds, and indeed, the entire rest of the article would be exactly the same if there were no such thing as a tangle channel.

On the latter, though, I first note this:

Reaching the inner engagement envelope implies either that one party is attacking or defending a specific fixed installation (such as a planetary orbit, drift-habitat, or stargate), or that both parties have chosen engagement. It is relatively rare for such battles to take place in open space otherwise, since in the absence of clear acceleration superiority, it is usually easy for the weaker party to disengage before entering their opponent’s inner engagement envelope. The only way to guarantee that an opponent will stand and fight is to attack a strategic nexus that they must retain control over.

…but let’s ignore that for a moment. Here’s why starship battles, whenever possible, are conducted in open space despite this, and why the inconclusive engagement-avoidance-and-retreat is also more common than the aforementioned at-nexus-point battle.

Because in space, a weapon once fired continues on until it hits something. Hopefully that’s its target. If it isn’t its target. hopefully it’s a clean-up fluffship, or something big and ugly enough not to care (like the star), or some Oort cloud object no-one cares about.

But the bigger the solid angle subtended by an object from the point of view of the fighting starships, obviously, the greater the chance that it’s going to be shot right in the face by misses, not to mention ricochets and debris. And the closer you are to an object, the greater the solid angle it subtends, by the inexorable laws of geometry.

This is why the defender has a strong preference for going out to meet the attacker, because letting what you are trying to defend get all shot up as a side effect of the process of defending it generally makes defending it in the first place somewhat moot.

This is also why many attackers have a preference for luring the defender out to meet them: because firstly, Omnicidal Maniacs aside, you may want to capture some of those defensible assets reasonably intact and avoid any unnecessary effusion of blood; and secondly, because being casual about smacking relatively fragile civilian habitats and inhabited planets in the backdrop with starship-class weapons is the sort of thing that leads to bad press, unwanted reputations, and awkward interviews in front of war crimes tribunals.

All of which is to say: naval strategists have a term for admirals who plan their defensive engagements at point-blank range rather than maintaining a healthy strategic depth. That term is idiot.