Sci-fi Military Tactics and Strategy

It is a pretty large territory to cover. Even FTL travel will leave patrolling a challenge.

Hmm...1800 Light years then?

Fastest ships can roughly do around 1760 LYPD so no world is more than a day's jump.

While not as large as the previous example it is still 10,200,000 light years in terms of area. Remember the area of a circle is appreciably larger than it's radius. It would take even the fastest ship over 15 years to travel through the total area. Even dividing your total force into patrol and task forces into 250 groups of 1,000 ships leaves each group responsible for over 40,800 square light years of territory to patrol. If they traveled constantly they would cover that space in just under a month. However patrolling means frequent stops, investigations, and of course time spent sweeping a system. Plug in Vladeck's density calculation and figure maybe a couple weeks to do a proper job and each sector will take a rather long time to do a single patrol sweep.

edited 29th Sep '17 3:34:23 PM by TuefelHundenIV

This discussion is making me laugh the pitifully small fleet numbers in Mass Effect and Halo.

No sense of Scale indeed.

And if we avert 2-D Space we realise that the empire is either a sphere or a cylinder with the outer half of a torus around it, at least roughly (other shapes are a pain is the ass to model mathematically) Which, of course, makes the whole patrolling business even more difficult, and is the reason I wrote about the number of stars instead of area or volume.

Though, with Star Wars' hyperlanes you could create chokepoints, albeit in a very limited manner. Just played Stellaris and realised again just how difficult it is to find any chokepoints in a 3000 star galaxy where I held about a tenth of available space. I don't wanna know how difficult it would be for a million-star empire (or one with 'just' hundreds of thousands of stars) to find and fortify them in a remotely effective and efficient way.

What can you say? Space is big.

Which is why Ungovernable Galaxy exists.

That being said, just because you have a 1800 LY territory doesn't mean that it's ALL inhabited. It just means that you may be able to explore it and colonize it at your leisure.

That's how the territory breakdowns in Mass Effect work.

The problem is still one of coverage if your talking patrols. "Empty Space" can still contain threats, outlaws, raiders, or even an enemy fleet. In order to control large volume of space you will need the numbers to make regular patrols. There is also a question of ship group sizes. For example what are the tooth to tail ratios of a given organization of ships? That is how many are things like repair, refuel, supply, munitions storage, medical ships etc vs how many are actually combat craft. A fleet may have a thousand ships in it but if almost half are support of some sort the actual combat strength is somewhat different.

edited 30th Sep '17 7:43:57 AM by TuefelHundenIV

Related to the first point, it is possible that your government doesn't even know about every colony (think religious sects or the like that want a place for themselves) And that may result in an invasion fleet out of seemingly nowhere.

And even if you don't have colonized each and every planet (and moon) it'll be still far too many stars to defend than that 250k ships would suffice. Or a million. I mean, if we assume that only half of the stars have 1 planet each and only 10% of those are colonized it's still hundreds of thousands of planets to take care of (again, galactic disc thickness of 1000 light years)

Speaking of Ungovernable Galaxy: Could a quantum entaglement-style communication network (or one that utilizes wormholes) change that by virtue of having (almost) instantaneous communication? I am thinking of a tree-like structure for the network, where it's possible for trees to intertwine.

Also impacting things, in addition to the FTL technology, is the communications/sensor technology. If you're limited to light speed, it becomes monumentally more difficult. If you have practical interstellar comm/sensors (I presume they go hand in hand), that can simplify things somewhat.

^^ Communications is but one reason why Ungovernable Galaxy exists. Logistics, security, infrastructure and isolation are other reasons.

Historically many frontier areas were almost effectively their own countries (or eventually DID become their own countries) because they had to provide their own security, had limited if any communication to their "home" empire or nation, had to provide for themselves logistically and by building their own infrastructure and were so isolated from other parts that they developed a unique way of their own that may or may not have clashed with the "home" empire/nation.

edited 30th Sep '17 8:22:29 AM by MajorTom

There is an easy way to have FTL Communication, but no FTL Sensors....

Thats that the FTL Drive is the only one that exists, no other FTL tech... Data Runners would return in mass numbers.

As a result, you still have faster then light communication, but not faster then light sensors.

edited 30th Sep '17 12:17:40 PM by Imca

But I'd guess that courier ships, while workable from a governmental perspective, would be impractical for larger amounts of data. Some kind of FTL radio would be better, though. (That said, it isn't necessary that Alpha Centauri can watch Earth television in real time)

But yes, FTL travel is possible, I am not sure about FTL sensors, though. Forgot to mention this as we already were talking about a verse with it

Actually, courier ships would be more effective for large amounts of data. Imagine an Uber driver with a trunk full of hard drives. When the vehicle can carry hundreds of terabytes of data, you might find it impractical to use it for only a few specific bits of data, depending on availability of couriers.

Well some sort of sensors and communications network would be needed to help take up the slack and reduce the need to constantly patrol an entire given area. Sensor nets are used in a similar manner to this in real life.

Rather than relying on the fleets to actively patrol you could do something like have stations or points of operation as centrally located as possible. These bases are tied into various sensor networks and the edges of the bases territory of responsibility are no more than a days travel in any direction. Now they can communicate with other bases in larger network so if need be they can pull in other nearby bases forces to assist.

This still presents a problem of patrolling. One of best answers is to localize patrolling as much as possible. Systems patrol themselves and/or nearby space out to half days travel at most. They are also tied into the sensor and communication network. They cover areas that don't have their own patrols or are "empty space".The bases house dedicated military assets who apportion a certain number and type of ships according to what situation may call for. Otherwise the locals do the bulk of the policing but are tied into a larger sensor and communications network that can all on assistance for anything form disaster relief, anti-piracy, rescue, war, uprisings etc. Overall it will still require a lot of ships but the localization will help reduce the strain of trying to cover large amounts of space.

edited 30th Sep '17 4:02:45 PM by TuefelHundenIV

I did remember Fox saying one of his factions had a 100 LY span at one point.

250,000 ships is much more doable then.

Depending on FTL method, wouldn't messuring the amount of planets rather then size work better? If FTL is fast enough you might span aa whole a but only control the 50 best worlds for instance.

Jas: His last two questions though was for two much larger areas. At 100 radius though that becomes a lot more practical in comparison. Dividing up the fleet in 1,000 ship units gives them an area they can span in less than a day. It would still take the better part of a month to span the entire area but you could more easily occupy a given point of space.

What would you say the maximum area would be? 300? 400? 500?

The idea is to have a *a lot* of ships from a realistic hard point of view, but soft enough where millions of ships aren't "needed", per se.

Don't want to be accused of having no sense of scale.

edited 30th Sep '17 6:29:48 PM by TacticalFox88

It depends on how heavily you want your space to be patrolled. If you want heavy patrols, you can go up to 300 light years in radius (about 1 star per ship on average). Light patrols could manage up to a 700 light years radius (10 stars per ship), and extremely light ones 1400 light years (100 stars per ship).

While I cannot directly model groups of ships jumping between stars, I think that the formula "that many stars one ship would be responsible for" is the best way to approach this, since patrols move and thus can form groups (e.g. a patrol five ships strong would be responsible for covering 50 stars).

But I know that feeling of not wanting to have no sense of scale. I have a setting in mind where there's a literal galactic war, and, well... The numbers are mind-numbingly high (one front has billions of ships on either side, and it isn't even the largest one) and I don't really know a way to make it less mind numbing besides making the war smaller.

Maybe give the ships some capability of long-distance FTL sensors, but still limited in comparison to the scale, necessitating patrols (rather than garrison fleets that stay in port until an enemy appears). If someone encounters a threat, they report it in, and then other ships may move in to reinforce them. Assuming that they don't think this is just a feint to pull other patrols off of their stations and open a gap.

I like AFP's idea a bit as well. Give the long range sensors low resolution but long detection ranges so the ships have to be within a light year or so to see details clearly.

Then again it also depends on the enemy. If they only have a few hundred ships to attack you with, you only need a few hundred more than they to defend yourself with. This is true regardless of how big the volume is. There are several historical examples of large space/low numbers warfare to draw from.

It's more tenable when you have all the important locations protected by static defenses. This means the enemy HAS to mass for an attack and you can force a head to head battle.