Years ago I was asked one of those questions that is fascinating. I was sitting at home with my flatmate (this was before I was married) and he asked me, “So what would a space battle really be like?”
And the problem is that, after pondering it, I had to conclude that the question was basically unanswerable.
I’m bringing it up because, as we all know, the Internets have no shortage of self-proclaimed experts willing to defend their vision of space-battles to the teeth. Often, they have very good arguments, because they’ve been thinking about this a long time. Sometimes too long. And they will rip into anyone, fan or writer, for not agreeing with them. But almost always, their superiority rests on a certain set of assumptions. Within those assumptions, they are very often right. But the assumptions have to be identified.
The first assumption that has to be addressed is the general level of technology you are fighting with. What is your power source? Your space drive? What weapons are available? What defenses? The beam weapon, the force shield, and the reactionless drive are all SF commonplaces. But they don’t always exist together. Which ones do, their power, and in what combination they exist all inform what a space-battle would look like.
A very well-realized universe for this is David Weber’s Honor Harrington series. With gravitic drives that protect ships absolutely from above and below, lesser shields (sidewalls) that protect them on the flanks, and vulnerable bows and sterns, his starfleets can resemble old Naploeonic-style sailing fleets. Cheap fusion power and antiacceleration fields enable the ships to accelerate at hundreds of gravities, and to launch missiles for long-range combat and use fixed-mount beam weapons at shorter ranges. Once you buy into all those givens, you have a system of “real” space combat.
But even once we’ve agreed on the technology, it would be difficult to answer the question. I mean, we might ask, “What would space combat look like with present-day technology?” That’s a better question, but then you have to ask a few more. Do you mean right now? That’s easy. It looks like robotic or remote-operated killer satellites trying to take out enemy recon satellites and stopping them from doing the same to us. Or do you mean, “What could we build right now if we really wanted to?” Because now you have to start asking questions like, “What’s the mission?” “How long do we have until we have to use it?” And, “Who are we fighting?”
It should be obvious that the answers to those questions will very much determine the answer to the original question. If the object is to invade or destroy a nation on Earth, then an offensive spacecraft would pretty much need to look like a bomber, ready to rain death on the planet, perhaps with defensive measures against nuclear-tipped missiles. How big the bomber would be would depend on how long we expected to need it. In a sense, an ICBM is a one-use, robotic version of this. Since we expect the enemy nation to be destroyed by using them, we don’t need them more than once.
Obviously, if the mission differs, so will the spacecraft, and so will the battle. If we need to shoot down an enemy space platform, what will we need? Missiles? Or actual space fighters? Or do we want to capture it, necessitating boarding equipment and tactics? What if we want to defend the planet against an unknown threat? Should we develop fighters? A fighter carrier? Or a really big battleship? Or what if we want to send a ship to mine the asteroids and we suspect someone would like to prevent that? Or capture the ship on its way back when its hold is full of valuable metal?
Our navies on Earth have a variety of ships to do a variety of jobs, form surface cruisers, to submarines, to aircraft carriers and a host of others. What a “sea battle” — or for that matter, a “land battle” “really” looks like depends very much on what forces are involved in accomplishing what objectives against what opposition. Space combat will, too.