Military Implications of Instantaneous FTL?

Question

In an example future world, one can use some form of FTL to instantaneously transport any ship from one point to another point (within the same galaxy, to keep things simple). The device required to do this is not excessively complex or large for an ordinary spaceship and does not require any sort of special positioning or calculation. These ships can move instantaneously from any position surrounded by hard vacuum to any other position containing hard vacuum (technically one can leave from in atmosphere, but that has nasty results for the surrounding area when suddenly the atmosphere contains a chunk of hard vacuum). However, another device that can block the entrance of FTL ships within a certain radius of it exists and can be reasonably used to block FTL travel within the orbital sphere of a habitable planet, within weapons range of a fleet of warships, or even within the inner system of highly developed systems. However, these devices do not prevent the egress of FTL capable ships.

This means that any ship can instantly retreat from a battle to any safe system, or even to some random interstellar location. However, this also means that when enemy ships jump to just outside the FTL restriction range of a fleet, the fleet can just instantly jump to somewhere else, which makes it virtually impossible to force a battle. Unfortunately, this means that two fleets will only fight if both think they can win the battle by a wide margin, which means battles will be quite rare, and this lack of battles makes military SF rather difficult to write. Therefore, we need a way to ensure that battles will still happen with some frequency. So, how do we ensure that battles are still frequent during wars when ships can escape with impunity?

Answer 1

Here are a few options:

• Short, non-deadly battles just as ships can escape, they can pop up (at least as close as possible and then fly in quickly), shoot, then disappear. This makes random bombings and shots-fired scenarios common, even if the damage is low.
• Battles shift to resource disruption - food will (probably) still need to be grown on planets. If you can't disrupt ships en-route, then you'll need to attack the source. A scorched-earth policy becomes important. Battles would often be forced around resources. Sure, the defending ships can escape, but that means leaving their food-source behind to be destroyed. Bad day. Sure, the military can place a ton of defensive weapons, but enemy ships can pop up, shoot, and leave quickly.
• No more small outposts any military post without significant defenses becomes readily attacked. If we lived in a world where every military base had to be defended out the wazoo, there would suddenly be fewer military bases. Any attempt to set up a new base would be heavily attacked.
• Extremely mobile military resources being able to move around quickly prevents the disruption of resources, especially en-route, but causes a technical headache for any general.
• Spies and subversion become increasingly valuable. If you know where resources are going to be before they get there, having mines in place would be valuable. If you have a spy on the inside who can disrupt or disable the FTL device, the enemy has the advantage. A sudden increase in the value of a single spy means increased rewards for defecting. The military is probably paranoid about spies already, but this would make the situation worse, leading to a cold-war style spy race.

Answer 2

The Home Front

The ability to appear and disappear makes bombing of the opposing civilian populations extremely appealing. This means that defensive forces have to concentrate near inhabited planets and try to spoil bombing attacks, and the attacker needs to thin down the defender's forces for the bomber missiles to get through.

The defenders are pinned by the need to defend the homeland. They can shift tactically, but they are limited in how quickly they can shift by the need to acquire and engage the approaching bombs, which will be hard to detect since they don't need to maneuver or radiate, and can be made stealthy.

Answer 3

I would defer to the ways FTL are implemented in certain space-sim videogames, especially since FTL as a game mechanic has to keep the gameplay balanced and challenging, especially for multiplayer games: they have to set the specific rules players have to abide by to make space battles engaging encounters and not annoyances.

• In EVE Online, ships are equipped with Warp drives for intrasystem travel. To prevent ships from warping out, players can deploy "warp bubble" devices to ensnare other players, which creates a small localized region of space in which a ship is unable to warp out, similar to your restriction bubbles. Such bubbles can be generated from a ship internally or via a launched probe, so that the bubble is movable. They can even be used to trap warping ships en route to a destination - so for your type of FTL, as it does not have a ship travel linearly from point A to point B, you could maybe have a scenario where a ship's FTL destination is known by an enemy party, to which the enemy might ambush them and prevent them from jumping out. Also, ships in EVE can equip a different type of device called a "warp scrambler," which is a type of emitted beam that disrupts a target vessel's warp systems as opposed to the more volumetric effect of the bubbles.

• In Elite: Dangerous, FTL travel is done via "Frameshift Drives." To help make them balanced, these FSDs have a significant charge-up time before they can be activated, and other ships can detect if a ship is charging up its FSD. Pursuing ships can also equip a special kind of device called a "wake scanner" - when a ship uses its FSD, it leaves behind a "wake" where it previously once was as residue that can be used by a wake scanner to determine the endpoint location of that jump.

• In Freelancer, one of the ways intrasystem travel is permitted is via cruise engines which require a short charge-up time to activate. Enemy players can deploy "cruise disruptors," small, fast missiles that, upon contact with any ship, stop their engines and prevent them from being able to charge for a short period. Escaping ships can try to deploy countermeasure flares to deter disruptor missiles, or, more creatively, can try to wind their ships around nearby asteroids or debris to avoid missile strikes (which can make for interesting story content).

Some combination of these mechanics could prove useful for your story.

Answer 4

Word from the future front: How will go the battle?

FTL necessitates time travel. From JDługosz' magnum opus Are there any ways to allow some form of FTL travel without allowing time travel?

Thus, due to symmetry, the FTL drive functions as a time machine. You can choose your spacettime axis, jump far enough to amplify the difference between time axes of different observers, and travel into your past using multiple jumps or travel into the past of another traveler

Like Nick Cage in the movie Next, one could use the time travel ramification of FTL to explore possible future scenarios. On planning a gambit, you could get word from the future about how the gambit turned out.

This aspect of FTL gets things hella weird hella fast - in something like a space naval battle you would be deluged with messages from infinite possible futures, and probably the délugement would extend far prior to the battle being engaged, or even considered.

Answer 5

You can include a charge-up time for the FTL Drive allowing the enemy to possibly disable it before you can escape. Something like an EMP warhead which would disable the engine and hence prevent escape.

Another way is that FTL leaves a warp signature which another ship can follow, meaning that someone who retreats can still be chased so even if you do escape, there is no true escape from an aggressive and obsessed enemy.

Answer 6

Strategy, strategy, strategy.

It will be a race to tech supremacy to see who can come up with the best stealth gear. Jump to just outside the sphere, engage full stealth mode, and get as close as you can before firing.

There will also be a tech race to see who can create the better 'anti-exclusion-zone' tech, that will defeat the effectiveness of the exclusion zone of the other side.

You can perhaps modify the situation slightly, so only one side at a time can create an exclusion zone, and allow that side to pop into their own exclusion zone. A 'home defense' smaller force could pop-and-shoot within their own exclusion zone. This encourages smaller fleets to stay and fight if they get the upper hand in forming an exclusion zone first.

A good tactic would not be to drop a ship in and then fire but to develop tech that would drop a bomb into the other side's exclusion zone right on top of the enemy ship and detonate immediately.

Have 'stealth bomb' mines all around just outside the exclusion zone.

Answer 7

This system of yours allows what Atomic Rockets calls a "suckerpunch". You FTL in, launch a couple of nukes and get out before anyone can stop you.

So first you need something against this. For example your FTL devices can also be used to detect and destroy such nukes through their radiation, you already have the "cant FTL into atmosphere" restriction to prevent close attacks and with nukes exploding high in the atmosphere they'll be a lot less dangerous.

Second, you can add a timer. After you jumped through space it takes a while to recharge. This sets the stage:

You'll never have enough ships to protect everything. So you gather them in groups nearby stragetic objects and leave lesser objects open. The lesser objects use those denial area's to prevent enemies from FTL'ing right on top. Now the enemies need to travel a bunch to get to the target while they recharge for another jump. This allows the defenders to call for help and FTL their own ships in. Now both sides can fight and maneuver. The one who thinks that he can win will try to engage sooner to prevent enemies time to recharge and have an instant escape, the other side will either try to do a holding off action or lure the opponents and punish them for thinking they have the upper hand.

Answer 8

You really cannot just pop in and out. To prevent coming out of FTL in the side of a planetoid, you need to have good, up to date navigational maps of the system you are entering with charted trajectories of all objects within it.

Now, to allow for interstellar trade, a detailed shipping lane would be published and updated often or safe points to drop out of FTL, but this would be highly defended by a strategically important system, thus deterring attackers from using this as their first line of attack. That is were espionage comes into play. an enemy would send scouts and probes to chart a system prior to an attack, and the defenders would search for unauthorized charting of their system.

This exclusion field would be massive and very expensive. Only rich and well established systems could afford them with the necessary defensive fleets to respond to violators. Small, newly established colonies would not be able to afford such defenses, so their best method of survival is to stay quiet and off everyone's RADAR. a random visit of a capital ship, large transport or cargo vessel would ensure their destruction. Even uncovering a mother load of "unobtanium" would be a death sentence until they either get well establish, get rich enough to build such defenses or obtain financial backing to build it based on their potential, be it strategic of financial potential of the system.

Answer 9

“...another device that can block the entrance of FTL ships within a certain radius of it exists”

What is the size of this device to provide a reasonable radius?

If there is a portable (in terms of starship size) FTL disabling device (FTL-DD), then you can force the battle by "wrap near the enemy fleet, turn the device on, start the battle". If any side doesn't have a FTL-DD then they just can't win (they might not loose, but not a chance to win this fight as the enemies can escape), and if they both have then the key of this battle then becomes which side can destroy all FTL-DD of the opponent first.

Even if you can instantaneous FTL, I think your enemy's surprise attack can still work. Think about it, you can instantaneously start driving if you sit in a car, but as long as you are not paying attention 100% of the time, another car can still hit you. Same for FTL, you can't be always prepared, so as long as the enemy chained their FTL with FTL-DD, you just don't have time to react.

Answer 10

The answer is simple: make it such that retreat is not a possibility.

While one may technically retreat, it's similar to desertion. There is almost nothing that prevents one from deserting the front lines, unless you're a Soviet army where the officers have orders to kill deserters. However, every soldier knows that the task they are devoting their life to is important (or is presumably important). Desertion is not an option.

Likewise, when a key strategic stronghold comes under attack, there is not an opportunity to just retreat and fight another day. Retreat means the attacker gets the spoils.

What really happens is the world just gets small. Everything that is not under FTL protection is just a place to hide. All of the edges of the FTL places are as though they were abutted up against one another.