What would "realistic" space combat be like?

Ok, so we can’t really get too far out there before technology advances far enough to render it a moot point. So, what’s the absolute simplest situation we can consider? Well, I’d say it’d have to be a moon colony vs. Earth situation. Anything with only Earth parties involved doesn’t work - it’s too easy for land-based weapons to scrap satellites, and way, way easier for them to dodge. It’d be nice to control space, but I suspect that between relative equals, nobody would have any satellites left after the first day. The only exception I can see is having the foresight to seed sleeper missiles in orbit, and hope they can get through whatever anti-missile defenses exist, but I can’t see much benefit to that over cruise missiles.

So, in a Moon vs Earth case, what are the objectives? Well, I can see two possibilities - either you’re going to want to be able to threaten to smack the other guy so hard they leave you alone, or you want to be able to land troops. In the first case, all you need to do is have the ability to launch missiles that can avoid whatever defenses the other guy has long enough to hit the target - either by making them hard to see (bearing in mind that you can use ballistic missiles, maybe with rockets for last-minute adjustments) or by making them big enough to not matter - that’s Heinlein’s boulder-cannon. In either case, the critical thing is keeping your launch system alive, which shouldn’t be too hard, just stick it on a truck and keep it moving, and make sure you have a missile shield. This is basically just an extension of current missile-anti-missile technology, nothing really new.

The big difference comes with the strap-a-rocket-to-an-asteroid strategy, but that’s a tough one too. First of all, it’s expensive - even if you start with a space rock, getting enough fuel to move something that big into orbit costs a LOT. Second, it’s slooooooooow, and if you have the tech to move it, your enemy probably has the tech to move it back (otherwise, it’s not space combat, it’s a space massacre), so you have to put on extra fuel to account for that. I suppose if you’re willing to plan months-years in advance, you could pick a really, really far away rock and get it going damn fast, so your enemy doesn’t have time to move it, but now you’re talking REALLY expensive, and they might wonder about the conveniently-targeted, accelerating asteroid.

Ultimately, I can’t really see manned spacecraft ever getting in a fight. Your ultimate targets are going to be stationary, and it’d be as easy or easier to launch missiles from the ground to intercept as from a spaceship. Depending on how good missile shields are, it’s either going to be a nuclear standoff, where everyone has the ability to kill everyone else, or a game of deception - no, really guys, that’s a freighter, and OHLOOKWEDECLAREWARTHEREGOESPARIS. As soon as two entities are at war, any non-missile spacecraft get royally smacked, and the political process determines who’s still alive.

As a final caveat, the Battlestar scenario, where you have space combat by dint of not having a planet - I still suspect missiles and flak rule the day here. The size of vessels that would be needed for large populations are essentially locked down by inertia, and function pretty much the same as planets for these purposes. One side fires missiles, the other side tries to swat them, rinse and repeat until somebody goes splat. There’s no benefit to having manned fighters that isn’t vastly outweighed by cost.

I recommend Martin Caidin’s imaginatively titled Cyborg IV, the last of his Steve Austin novels. The gist of it is American and Soviet spacecraft having skirmishes in orbit and it certainly seems plausible.

“Sir, long-range scanners detect an incoming enemy ship 60 million kilometers out. Their weapon systems have inferior range to ours.”

“Begin matching velocities, bombard from maximum range, let me know when target is destroyed.”

…several weeks later…

“Sir, enemy target was vaporized.”

“Good work, ensign.”

The biggest problem is that if you have two opposing fleets in opposing orbits around a planet, they would be passing each other at tens of thousands of miles an hour.

Exactly…their engagement window would be pretty small (though if they were using kinetic weapons they would hit a lot harder I suppose). I also don’t see space combat as being in close orbit around planets (though of course they would be in some kind of orbit), as to my mind the whole point of space combat would be to get in range of a planet to drop big rocks (or something) on it. If and enemy fleet was already in close orbit they would already be in position to bombard the planet…in fact, they would have been in position long before they achieved close orbit. The point of space combat IMHO would be to keep them as far away as you could from your planet(s)…make them have to fire from very long range at your planet to give you maximum intercept possibilities.

Though some of it is unrealistic, I really like the space battles in the Honor Harrington series. Though they leave out the relativistic effects of traveling as fast as they travel in ‘hyperspace’, and though they have ridiculous accelerations (and inertial compensator and anti-gravity and such), Webber is pretty good about the time it would take and how you’d need to match vectors to bring your fleet into engagement range.

BTW, one thing no one has talked about is how the crew is going to man the ships. Unless we are talking about spinning the ships for artificial gee, or generating some kind of gravity, they are going to essentially be in zero-gee environments. That’s going to make getting hit by anything…interesting. Myself, I envision the crew in armored life support pods, perhaps using robots via waldos or other human directed means from their stations to repair battle damage. It would be totally unlike Star Trek/Star Wars…or even a modern naval vessel. What I was thinking is the crew would be hooked in using VR that would generate avatars of each other (for psychological reasons…being in an enclosed box all by yourself would suck going into battle) as well as their stations ‘controls’.

-XT

Another point to IR location. I would think it would be fairly simple for a reconnaissance or other vehicle to actively supercool the section towards the target and radiate the energy off the back side where it’s less likely to be observable.

The problem with getting in close orbit to drop stuff on the planet is that you’re also close enough to get hit by missiles. At that point, we have two more-or-less stationary targets (ok, so the orbiting ship is hardly stationary, but it’s predictable) that can shoot at each other, except that one of them is much, much more fragile. If you’re in a position to sit in orbit without getting shot at, I’d think you’d have already won, no? Why not just sit farther out, and send in the missiles? When you’re talking about interplanetary distances, you’re already spending the fuel to get the missiles there anyways, so why bother with a much more expensive ship?

That’s why I don’t think ships would get into close orbit to bombard planets…and why I think space battles will be fought fairly far from habitable planets or other colonies. You could probably bombard a planet from fairly far out, though you’d want to get close enough so that the defenders wouldn’t have months to try and intercept your attack. Then only think I could see getting close to a planet would do for an enemy fleet would be to land troops…and you simply couldn’t put enough troops in a fleet to take a planet like the Earth. Perhaps you could take out a colony like one on Mars if they had a fairly low population though.

-XT

The heat would dissipate into space and leave a corona around the field of cooling. The only way to mask a ship would be to control all forms of radiation, and then that would only work against energy detection devices. Visual forms would still be able to pick it up.

Give up on the stealth ship idea, it’s just not feasible.

The further you get from the habitable planet the more difficult it is to intercept your enemy.

Occupation is a whole other issue, and would expand the scope of this discussion too much for it to continue I should think.

This combined with good insulation for the crew quarters would go a long way toward making the ship harder to detect. It does require that you know where the observers you’re hiding from are, though. Good for an assault on a planet. Not so good at trying to remain unnoticed in general.

It would depend on where you pre-positioned your own fleet and how far out you could detect an enemy fleet. In order to intersect with a target planet there are only so many vectors you could use if you were trying for a least time approach after all…especially if you are limited in where you were able to come from. My guess is that the reasonable approaches would be watched and you’d at least attempt to pre-position your own fleet to try and cut off those approaches.

You are right about the discussion about space invasions though…while it just might be possible to have combat in space some day, I can’t see how we would ever get to the point where we could bring enough troops to occupy a planet like the Earth.

-XT

Well, basically I’m saying why bother even having a ship, when you can just launch guided missiles from your base? Even if you send the ship, they still know you’re coming months off, but now you have to spend vastly more money on lugging people around. You’re already having to launch your attach months-years in advance, so what I would see as more likely would be essentially interplanetary cruise missiles. Because you can track all your opponents ships/missiles by their thrust, even the lag time between Earth and Mars isn’t going to be an issue until the last moments, when I’d imagine you’d want to be using a computer guiding system anyways.

Basically, I’m saying I don’t see a place for ships at all - the war would be fought between missiles and whatever anti-missile defenses exist, without the need for expensive, fragile, concentrated targets.

Well, let me pose a different question to you…why have a Navy? After WWII the Air Force made a strong case for getting rid of the Navy completely. What purpose does it serve if one can lob missiles from here to Russia and vice versa?

In space of course the reasons would be different…but the answer is that a Navy allows you to project power. It’s also mobile. Perhaps if we are talking about a war between worlds within our solar system you’d be right…though I still think mobility would be key (after all, you’d be able to predict exactly what orbits an attack would have to come from if, say, missiles were launched from the surface of Mars to impact the Earth, or Earth to Mars…and you could focus your anti-missile defenses on pretty much every possible window for any reasonably timed attack…and if they were going to use some weird attack vector that took 10’s or 100’s of years it’s probably not something you are going to need to worry about soon).

-XT

Just thought I’d point out that insulation does not eliminate heat, it merely slows the transfer of it down. Highly insulated crew quarters would just mean that the interior would get hotter and hotter (from body heat and whatever other machinery is inside) until it reached a high enough steady-state temperature where the heat radiated would be exactly the same as the un-insulated quarters.

Hmmm… that’s a good point. I have to say I don’t really know. One of the main things a navy/on-site manned craft can do vs. cruise missiles is ongoing operations - especially with aircraft carriers, I’d think it’d be cheaper and quicker than setting up an airbase in the region. Here’s where my lack of knowledge about our military shows - I don’t know the relative costs of having a ship full of missiles vs. ICBs, but I’d imagine it’s cheaper to ship them halfway, which wouldn’t be the case in space.

The other thing I can think of is the issue of controlling the seas/orbits. If you’re in a position where you don’t have to worry about an equal powered navy, you’re going to have a different focus than if you’re overwhelmingly stronger than potential enemies. So, if you have an occupation force, I think it’d be great to have a space force overhead, but if you’re attacking someone with missiles capable of hitting you in orbit, maybe not so much. Frankly, I know basically jack about navies more modern than Nelson’s - anyone care to enlighten me?

I really don’t know much about space or the military, but I hope I can be forgiven for speculating.

  1. The primary problem with space is the cost of launching anything into it. It costs what, about $10,000 per pound of item to be launched into orbit?

  2. Humans, and even more, their need for life support equipment, weigh a lot. They will be a minimal on-scene component of space warfare until #1 changes.

  3. Stealth favors smaller, lighter objects over larger, heavier ones.

  4. The only place really worth being right now in space is low to geosynchronous Earth orbit. Even should humans return to the moon or go to Mars, they’ll be busy enough staying alive, and have no energy to spare to affect a war on Earth.
    I think that as a result of these factors, space combat would make really poor sci-fi movies. Realistic space combat will entail robotic satellites and microsatellites duking it out over destroying enemy communications, navigation, and spy satellites. Defending your own will be almost completely pointless – the only defense will be having a satellite that’s small and stealthy enough to evade detection, and still get the job done.

Imagining a war between two space powers (say, the U.S. and Iran in 20-30 years from now) – it would likely begin with massive antisatellite strike by whichever side starts the war. Pretty much every thing that broadcasts (GPS satellites, communications satellites) and is known to belong to the enemy is hit at about the same time. Pre-positioned orbiting antisatellite weapons are preferred so your enemy doesn’t mistake the antisatellite attack for an ICBM attack.

Retaliation takes a bit longer, as the victim hasn’t pre-positioned as many antisatillite assets, but ground-based antisatillite weapons might play more of a role here.

After a little while, survival is either completely dependent on stealth (in the case where both sides still have the ability to shoot down the other’s launches.) Or one side has space superiority, where they can launch, and the other side doesn’t have the ability to track and destroy those new launches.

I think such space warfare would take place very quickly, with the initial attack being over in a matter of hours, and if one side can establish space superiority, it will take only a matter of days to weeks.

Because not every conflict requires intercontinental nuclear missles. Nuclear missles also cannot hold or defend territory. Let’s start from the other end. A conflict that only requires the deployment of a Navy SEAL team or at most a regiment of Army Rangers. You would still want them to have the support of local air power, which can be provided by a carrier and it’s battlegroup.

In the future, it might become necessary to deploy a squad of SEALS or Space Marines or whatever to some manned colony on Mars or the Moon or in a space station around Jupiter.