Reading through the various excellent pieces on space warfare, I couldn’t help but notice that particle beams of various sorts aren’t included in the kit of the typical war rocket. I know that particle bloom screws with range, but there are ways of mitigating this, and besides, Ultra-Relativistic Electron Beams/Bombards are just so fucking *cool*.
(I was also wondering about things like macron guns and magnetohydrodynamic weapons, but I figure those go under the “mass driver” category)
And that’s the exact problem. Remember how far away the ships are in a battle, even your point defenses are reaching out to a light-second. 50,000km is your point defense range.
Well, there are a number of reasons. (Plus, of course, from a Doylist perspective, the need to preserve the existing meta. Once you have a published canon out there, you don’t get to rewrite it.)
Where most particle beams are concerned - in things established in the early days of history when the range limitation on early particle beams was less relevant - a key consideration was the question of good taste, which may seem like an odd consideration in warfare, and yet.
Specifically, that while mass drivers and lasers are effective ship-killers (and people-killers for anyone who gets in their way), particle beam weapons have a nasty habit of achieving ship-kills while leaving behind a lot of technical survivors with acute radiation syndrome and every kind of cancer at once.
Not that this would stop some people from using them - or, to be fair, most people from using them if they were unreasonably effective enough to outweigh other considerations - but in practice the two big other considerations:
…won the day.
Not that there aren’t plenty of prototypes sitting around the labs and special weapons packages in storage for special occasions when they are unreasonably effective enough, in context.
Things got worse for conventional particle beams with the invention of the kinetic barrier, because the ability of kinetic barriers to deflect incoming massy objects is strongly dependent on their inertia, and hence inertial mass. Since individual particles have really, really tiny inertial masses, kinetic barriers are exceptionally good at scattering particle beams - they’re an even better defense against particle beams than they are against the macroscopic k-slugs they were built to defend against.
This also affects the usefulness of macron guns, obviously, which trade off mass for velocity.
But, I hear you ask, doesn’t this also affect the small-fast-projectile model used for slugthrowers in the 'verse in general? Well, yes, but they’re still a lot bigger than macrons. In general, one can assume that since the days they were first invented, innovators in both slugthrowers and kinetic barriers have been wrestling over which part of the mass/velocity tradeoff curve is the effectiveness peak, and sliding it back and forth. As always, a snapshot of one historical moment isn’t a picture of everywhen.
Macron guns have found uses on occasion (they were a popular choice for point-defense systems, for one, competing with laser grids), but kinetic barriers meant they lost the war for mainstream weapons system use.
Magnetohydrodynamic mass drivers (in the sense of Reaper cannon-type MHDMDs) have been prototyped, but never really found a military niche. It’s a combination of factors.
One, a lot of their advantages depend on their ability to keep a sustained burst on the target, and the nature of a lot of space battles is that until they’re already crippled, you’re not going to get a sustained burst on the target. At long range, they’re drunkwalking and you’re shooting at longscan projections of the probability envelope of your position, trying to trick them into walking into your shots by setting up a hard-to-evade time-on-target puzzle, which small discrete shots are better for; and at short range, the DDs, FFs, and tiny AKVs are dancing to stay outside the solid-angle steering capacity of your weapons - you can get momentary firing solutions, but sustained firing solutions don’t happen unless you’re sluggish at suicide range. In which case you can just lase 'em into cubes.
Two, while it doesn’t hit them as hard as particle beams, plasma, or macrons, liquids are still easier for a kinetic barrier to muck up than solids, because it’s still less effective at making you deal with the entire inertial mass of the jet at once. Nature of the bonding, and all that.
And three, you have to substantially up the complexity of your turrets and your magazines compared to regular k-slug mass drivers, and deal with keeping a whole lot of molten metal around in your heat-budget constrained starship. Not that that isn’t well within local technological capabilities, but you’ve got to have an advantage coming from it to make the game worth the candle.
As a side note on the general love of the IN for conventional gravomagnetic mass drivers:
Specifically, it’s the flexibility. You can use them to fire regular k-slugs. You can use them to fire a remarkable number of variants on regular k-slugs (be it special weapons packages like SPLITSHANK RIPPER, or more common varieties, even all the way down to “case shot and langrage”). For the big ones, you can use them to deploy torpedoes, probes, AKVs, satellites, cargo pods, boarding spikes, rope lines, and, hell, Legionaries, not to mention just about anything else you can put in a fairing and fit in the breech.
This is useful to bear in mind when thinking about other weapons systems, because until you can match that sort of flexibility, and do so without requiring comprehensive updates to everything else, you’re not selling a replacement for the good old mass driver, you’re selling an addition to it.
Things do change for particle beams once you enter the ultrarelativistic regime, but this post’s already huge. I’ll be back in a bit to talk about UREBs in particular.
What’s this one? I’m having trouble finding any results for it in the site search.
Projectile that exploits the Penrose effect around a black hole for added kick. See the later episodes of Epistolary Experiment
So, I found time to do a little reviewing on UREBs specifically (since they became particularly popular in SF circles since the ‘verse meta for the main time periods I write in was defined, so…), and came to some conclusions.
And a lot of it boils down to the same problems with regular particle beams, I was slightly surprised to discover. Particle bloom is less of a problem in the ultra-relativistic regime, certainly at useful combat ranges, but in other terms –
(Be those “niceness and good taste”, “kamikaze-encouragement avoidance“, or “the IN will kill you, then kill you again, then kill you some more just to hammer the point home that some things are Not Done”.)
You’re going to lose a bunch of power in the shielding to do it, mind, but those systems are built with that in mind, in short bursts.
3. Also, the same range concerns are problematic. UREBs work best with sustained dwell on target, and their killer application is long range - but at long range, because you’ve got nimble drunkwalking ships, you don’t get sustained dwell. I think, based on my back-of-envelope scratchings, you could get UREB burn-throughs and kills at short range, but you could also do that with lasers, and they have lasers, in smaller and more convenient packages than UREB generators would fit into.
So, to sum it up, I’m pretty sure that UREBs are around as prototypes and special weapons packages - and almost certainly some ‘verse rogue states have figured that they’d be great terror weapons, as the ability to give entire civilian habitats (not known for their evasion or military-grade shielding) acute radiation syndrome from light-hours away is exactly the sort of idea that appeals to the creative sort of terrorist.
But so far as the IN is concerned, they don’t play well with their flexible-fleet doctrine, against their existing defensive capabilities, or with the rules of civilized warfare they’re big on enforcing, so…
Originally designed as gamma-ray reflectors, in fact. ↩︎
I was thinking of using something like molten tin as the working material and you’re heating it because it’s your heat sink material. Not exactly thermal goo, but possibly viable for long-battle “screw yous”