The comments for that post were very active with suggestions for technological or strategic situations which would or would not make orbit-to-land operations (read: planetary invasions) unnecessary or obsolete, which were all quite interesting.

What I found most striking though was a relative confidence in how space battles would be waged in general, which I’ve seen both a little bit here in the comments and frequently more broadly in the hard-sci-fi community. The assumptions run very roughly that, without some form of magic-tech (like shields), space battles would be fought at extreme range, with devastating hyper-accurate weapons against which there could be no real defense, leading to relatively “thin-skinned” spacecraft. Evasion is typically dismissed as a possibility and with it smaller craft (like fighters) with potentially more favorable thrust-to-mass ratios. It’s actually handy for encapsulating this view of space combat that The Expanse essentially reproduces this model.

And, to be clear, I am not suggesting that this vision of future combat is wrong in any particular way. It may be right! But I find the relative confidence with which this model is often offered as more than a little bit misleading. The problem isn’t the model; it’s the false certainty with which it gets presented.

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Coming back around to spaceships: if multiple national navies stocked with dozens of experts with decades of experience and training aren’t fully confident they know what a naval war in 2035 will look like, I find myself with sincere doubts that science fiction writers who are at best amateur engineers and military theorists have a good sense of what warfare in 2350 (much less the Grim Darkness of the Future Where There is Only War) will look like. This isn’t to trash on any given science fiction property mind you. At best, what someone right now can do is essentially game out, flow-chart style, probable fighting systems based on plausible technological systems, understanding that even small changes can radically change the picture. For just one example, consider the question “at what range can one space warship resolve an accurate target solution against another with the stealth systems and electronics warfare available?” Different answers to that question, predicated on different sensor, weapons and electronics warfare capabilities produce wildly different combat systems.

(As an aside: I am sure someone is already dashing down in the comments preparing to write “there is no stealth in space“. To a degree, that is true – the kind of Star Trek-esque cloaking device of complete invisibility is impossible in space, because a ship’s waste heat has to go somewhere and that is going to make the craft detectable. But detectable and detected are not the same: the sky is big, there are lots of sources of electromagnetic radiation in it. There are as yet undiscovered large asteroids in the solar-system; the idea of a ship designed to radiate waste heat away from enemies and pretend to be one more undocumented large rock (or escape notice entirely, since an enemy may not be able to track everything in the sky) long enough to escape detection or close to ideal range doesn’t seem outlandish to me. Likewise, once detected, the idea of a ship using something like chaff to introduce just enough noise into an opponent’s targeting system so that they can’t determine velocity and heading with enough precision to put a hit on target at 100,000 miles away doesn’t seem insane either. Or none of that might work, leading to extreme-range exchanges. Again, the question is all about the interaction of detection, targeting and counter-measure technology, which we can’t really predict at all.)

And that uncertainty attaches to almost every sort of technological interaction. Sensors and targeting against electronics warfare and stealth, but also missiles and projectiles against point-defense and CIWS, or any kind of weapon against armor (there is often an assumption, for instance, that armor is entirely useless against nuclear strikes, which is not the case) and on and on. Layered on top of that is what future technologies will even prove practical – if heat dissipation problems for lasers or capacitor limitations on railguns be solved problems, for instance. If we can’t quite be sure how known technologies will interact in an environment (our own planet’s seas) that we are intimately familiar with, we should be careful expressing confidence about how future technology will work in space. Consequently, while a science fiction setting can certainly generate a plausible model of future space combat, I think the certainty with which those models and their assumptions are sometimes presented is misplaced.

Bret Devereaux, “Fireside Friday: August 14th, 2020”, A Collection of Unmitigated Pedantry, 2020-08-14.