This world has 3 forms of faster-than-light travel:

  1. Warpdrives don't require destination coordinates. They can be activated and deactivated at any time to move continuously through space. But they are the slowest of the three, and are easily tracked and detected.

  2. Wormdrives require precise destination coordinates. The Wormdrive mounted on your ship creates a temporary traversable wormhole that starts in front of you and ends at the destination coordinates.

  3. Wormgates are two wormdrives linked end to end. You need one ship at the start of the wormhole and another one at the end.

All three forms of travel work on the same principle. They all require precise calculations tailored to the exact mass of the craft. They all become unstable with prolonged use. This is why the wormholes are closed after use.

My question is can wormdrives, wormgates and warpdrives in this scenario exist without making any of them obsolete?

How could I justify why wormgates need a destination gate? And are there any other redundancies or more efficient ways to use this tech I have overlooked?

This is very much a work in progress and yes I'm over thinking it.

Edit: Renamed Jumpgates to Wormgates for clarification. Reworded my question and added a bit on warpdrives.

  • $\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$
    – Community Bot
    Commented May 5, 2022 at 8:59
  • $\begingroup$ Is there a cooldown to using either wormdrive or jumpdrive? Does using one triggers the cooldown for the other? Do jumpgates also require careful calibration based on ships' weight or can they wave those away? $\endgroup$ Commented May 5, 2022 at 9:24
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    $\begingroup$ The Stargate movies and TV series included FTL gates and drives (and ascended beings could directly teleport anywhere they wanted). I think at some point the show's characters explained the advantages/disadvantages of each mode of travel. $\endgroup$
    – RobertF
    Commented May 5, 2022 at 20:24
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    $\begingroup$ I encourage you to take a look at David Brin's Uplift trilogies. At least three distinct types of FTL travel are used regularly in that setting, a fourth is explicitly mentioned multiple times (but considered too dangerous by most races to even consider using), and it’s implied that there are more possibilities beyond that. $\endgroup$ Commented May 5, 2022 at 20:52
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    $\begingroup$ Peter F Hamiltons later Commonwealth books have all three modes of travel you describe - wormholes for both ground and space based point to point, wormhole-based FTL for cheaper-but-slower travel, and hyperdrive/ultradrive for faster travel. Used to good effect in the series. $\endgroup$
    – Moo
    Commented May 6, 2022 at 10:15

17 Answers 17


Planes, trains and automobiles

enter image description here

The different forms of FTL travel are the same difference between walking, cycling, driving, and flying on an airplane. The later methods are more technologically advanced. They are faster. But they are also more expensive.

Airports are large and take a long time to build. So they are specialised for long trips. You cannot fly to work in the morning by airplane.

Warpdrives, Wormdrives and Wormgates are like a bike, a car and an airplane. Yes you can in principle use any one for any trip. But some trips are too short to pay to open up a whole new pair of wormholes. And some trips are too long to navigate hyperspace yourself.

Why do wormgates need a destination gate: The same reason airports only send planes to other airports. It makes things much easier. By using a target gate and using the same one every time, it becomes easier to send large things through. You also only have to make the link once. So wormgates are longer range than wormdrives.

The photo is Steve Coogan and Jackie Chan from Around the World in 80 Days.

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    $\begingroup$ I suppose the predictability and safety of a destination gate is an advantage even if it is not technically needed to make the jump. And certainly cost could be a factor, wormdrives may be prohibitively expensive for shorter trips over warpdrives. $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 13:09
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    $\begingroup$ @Stargazer Keeping the plane/train/automobile analogy, it may also be a location issue. Wormholes (like trains) may only be able to be open at certain "stations" or might only be able to travel on particular paths. The "last parsec" might need a warpdrive to cover. So in a complex trip, you might use all three modes: take the car/warpdrive from your home/planet to the closest train station/jump point. Then take the train/wormdrive to the airport/wormhub to catch the plane/wormgate across the country/galaxy, and then reverse the process to get to your destination address/planet. $\endgroup$
    – R.M.
    Commented May 5, 2022 at 18:00
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    $\begingroup$ Nitpick: "You cannot fly to work in the morning by airplane." While not common, there are people who have an airplane flight as their daily commute in each direction. $\endgroup$
    – Makyen
    Commented May 5, 2022 at 21:23
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    $\begingroup$ @Daron Surprisingly, there are people in a wide variety of jobs which are not otherwise associated with airplanes who use aircraft to commute. It's rare, but it does happen, even for jobs which you'd really not think it would be "worth it". $\endgroup$
    – Makyen
    Commented May 6, 2022 at 0:55
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    $\begingroup$ If not all ships or ship owners can afford a FTL device, having access to a wormgate is a godsend $\endgroup$
    – STT LCU
    Commented May 6, 2022 at 8:17
  1. Risk.

    Wormgates are in space and some weasels clear space next to them. Jump is 100% safe.

    Wormdrive is risky. You do not know that your travel will not end with a collision with an asteroid right after the jump.

  2. Calculation power.

    Wormgates have powerful computers and calculate travel precisely.

    Wormdrive on ship - You need to make the calculations little rounded. No problem to be couple thousands km from target in space. But if you try to jump next to a planet, then can end in the atmosphere or worse in the core.

    And gates can calculate a route to anywhere. Ship - some militaries have good enough computers to do math for 1000 parsecs, but most are limited to 10 LY.

Why use drives then? Military, smugglers with illegal goods and guys who do not want(or can) to pay GATECORP their fees.

  • $\begingroup$ I like the risk evaluation, They could know the coordinates of a planet but you can never know stray asteroids, debris or even other spacecraft. And the rounded calculations pair nicely to give them a disadvantage on travel time. I'm unsure why there would be a limit on distance if the navigational computer has the data, limit on the amount of location data maybe? And Wormgates could have a destination zone at popular destinations that is kept free of obstructions. $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 10:28
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    $\begingroup$ Upvote because it is high time someone acknowledged the efforts of the space weasels to keep us all safe. Also I am a devotee of those illegal gods. $\endgroup$
    – Willk
    Commented May 5, 2022 at 21:42
  • $\begingroup$ @Stargazer: When calculate route in wormhole You need to calculate influence of all major sources of gravity beetwen points. You cant go through a big gravity object - like planet or star, small sources like ship or planetoid theoretically can break path but there is rule of mass - something like mass need to be 1 000 000 bigger than mass of traveling object to break wormhole. $\endgroup$
    – Kamitergh
    Commented May 6, 2022 at 13:04

The most obvious point here is... how do you use an FTL gate, if the only place you can put the destination gate is within sublight-attainable distances? Woohoo, 10 years to set up the Oort cloud gate!

So, FTL drives are important. They might be outlandishly expensive, but you could build as few as finances allow, and use those to dump gates at the other end... with tourists pouring out the other end almost as soon as you turned them on.

As for having two different FTL drives, that can be chalked up as technology marching on. Even for far more mundane technologies, we often develop multiple competing methods. One is more convenient than the other in most cases, or cheaper to operate (or cheaper to construct). Even if there aren't very many advantages to one over the other, you would see humans invent both just for experimental purposes.

It might even be the case that a company has some long-lived patent on the one drive, and a competitor just sidesteps that with an alternative operating on a completely different principle.

  • $\begingroup$ Good point, I can imagine the warpdrive came first. Then the discovery of traversable wormholes made way for the wormgate, constructed thanks to warp speed expeditions, then the expensive, downsized ship-mounted version of the wormgate the wormdrive finished it off. $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 13:51

You just described interplanetary and interstellar transports.

The wormgates are awesome for ships without any drives. They take you to and from one planet to another, or even across interstellar distances! But without an internal drive you will be limited to only those gates. Thats fine for many types of transport, but not all.

The wormdrives are for the mainstay transportation to known bodies. You might not want to use a gate because of waiting lines or because the gate is on the wrong side of the planet or the planet you go to doesnt have enough traffic to justify a wormgate. So you use the wormdrive. The wormdrive has to open a hole at both locations so if you dont know the proper location you could end up very far from your intended destination.

Warpdrives are for transport to places where you dont know the exact positions. It may be an asteroid belt, or the distance to the planet is so large and your charts arent detailed enough to know the coordinates at the exacting standards necessary. Or it could simply be an expeditionary action to set up gates or discover if a solar system is worthy of your attention.

Edit: seeing that you want a limitation on the range of wormdrives there's two ways (3 if you combine them):

  • to gather data about your destination point requires a minimum scanning resolution, relying on a database can be unreliable as the exact composition of the local area can be different (and all matter changes local space-time).
  • you need to open two portals, one at your own position which is easy and one at the destination point. Projecting the power that distance can be HARD. Imagine using a laser at that distance, you need a masssive focussing array to achieve it or else the laser will spread out too much. A Wormgate might be able to pull it off but its so much safer and cheaper to just hold the wormhole open on both ends with a seperate gate.
  • $\begingroup$ Variation: wormdrives use publicly published location data. The exact coordinates are way, way too hard to calculate (look up N-body problem; now do it at a galactic scale!), so we simply measure the precise locations and update them regularly. $\endgroup$
    – Vilx-
    Commented May 5, 2022 at 21:35

As I read the question, it's a bit hard to understand what you are asking. Assuming that you mean, How can I justify the existence of these three types of FTL without making any of them redundant/obsolete?


Say this operates at a level similar to the Alcubierre driveand StarTrek™. Requires a great amount of power while in operation. Though not so much that it would be out of the reach of commercial enterprises or even wealthy individuals. Also Power requirement scales with ships mass. The larger more massive the ships, the more required power supply to generate and maintain the warp bubble. Travle time and warp class may be expressed days per light year. Or hours per light year. ie: 20/1 would be 20 hours to one light year, or 90 hours to Alpha Centauri or 3.75 days. Adjust as you see fit :)


Is a stationary structure that must be located in a region of spacetime that is "flat" or rather, free from major gravitational disturbances. usually outside of any major planetary / stellar orbit. As gravitational waves disrupt the formation and stability of the wormhole used as transport. WormGates consume Vast amounts of energy especially upon formation. Far and above what is needed to sustain a WarpDrive. Therefore they are only constructed in systems that have large amounts of traffic between them. Though the power needed to transport ships scale with their mass it is not nearly so great of a curve as warp drives. No special equipment is needed to use a WormGate and any craft may pass though as needed. The structures are needed on both ends so as to:

  • Provide a stable endpoint to the space-time tunnel.
  • Share the power requirement to keep the conduit open.
  • Provide telemetry and to regulate traffic though the endpoints.

Only governments and major toptear corporations can afford to operate WormGates as the infrastructure, technology required are diverse expensive and quite complex.

Wormdrive: Operate on the same principle as WormGates except since the travel is on demand. Thus, they may initiate the worm drive in areas not suitable for a worm gate, though they do still need to be in an area of "flat" space time, and again at any time they chose to virtually any destination they chose. However making jumps to areas they have no telemetry or areas they are light years away on the only intel available is Visual / Radio astronomical data. What is actually in the area when you jump to it may be vastly different than observed light years ago. Initiating a Wormdrive jump requires as much power as does initiating a WormGate connection.Although there is no ongoing power requirement after the jump. Also the computational requirements are much higher as the traveler must computer start and endpoint dynamics not to mention among many data points differences in the relative delta V of there destinations. As with WormGates only top tear Corporations and government / military could afford to operate such devices. Costs are farther above even those of WormGates. Indeed, considering the strategic value of the nature of the technology it is highly likely that it may be restricted to government and Military uses.

NOTE: ships may have WarpDrive and WormDrive, but may not operate at the same time. Do not ask what would happen if a ship operating a WarpDrive entered a WormGate...

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    $\begingroup$ I'm fascinated with the technicalities of equipping a ship with both drives. Maybe even operating only one at a time still disrupts the system of the other, requiring on the move minor repairs every time and therefore this usually prohibits installing both unless money isn't a factor. And of course its detrimental to crew and ship if both are activated at once. $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 13:41
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    $\begingroup$ Thought just occurred to me. WormGates may not require both ends...BUT just like with a WormDrive, what happens when you pop out at your destination is iffy. More or less a game a russian roulette. If there is no "beacon" (for lack of a better term) on the other end, you may not ever arrive. Or just arive as a giant expanding ball of hard radiation / gamma rays and x-rays. So in Essence you have to slowboat it there with a WarpDrive and Build a gate first. Then its easy sailing from then onward. $\endgroup$
    – Gillgamesh
    Commented May 5, 2022 at 20:34

Largest difference is travel speed

Worm gate (long distance):

  • Can be much larger and have more power generation, wormhole stabilizers, wormhole creators, etc.
  • Can connect to a much further distance so the travel speed is much faster.
  • Maybe can create wormholes much faster and do mass calibration much faster.
  • Maybe can use cheaper components because they don't have to be miniaturized.
  • Can be used by crafts lacking wormhole travel.
  • If can connect to another wormgate, then can increase the distance even further.
  • Maybe the length of the inside of the wormhole can be shorter so the traversal time is faster?
  • High precision so that you arrive very precisely at target coordinates.

Worm drive (medium distance):

  • Require a long time to stabilize and adjust the formed wormhole, before safe traversal can occur.
  • Precision is lower especially over larger distances, so you probably have to use FTL once more to reach the desired destination.
  • Maybe another ship can acts as the other end of a wormgate and increase the travel distance. Useful for reinforcements. But this might have a long setup time.

Warpdrive (short distance + combat)

  • Can be activated quickly so more useful in combat or for short distances.
  • Maybe a difference in price compared to the others?


  • Maybe most civilian crafts only use one of the FTL types, because of cost, weight and volume.
  • Maybe have specialized carrier vessels that can transport smaller craft?

Edit: Maybe the wormdrive can open many small wormholes in succession to try and find the correct settings to arrive at the desired destination. Probing the destination...

  • $\begingroup$ I like the precision of destination coordinates advantage, I also like the idea of faster wormhole generation! Could say the warpdrive is the oldest FTL drive before the discovery of traversable wormholes and is therefore cheaper. Carrier vessels are a fascinating idea, could have a space ferry equipped with a warpdrive to transport small craft shorter distances, like to and from worm gates? $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 13:04
  1. Wormgates/Wormdrives have a minimum practical range.
    So one would want to use Warp for insystem use, nobody wants to spend six months on the way to Mars when Alpha Centauri is just an eyeblink away.
  2. Wormdrive is slightly inaccurate, destination Wormgates stabilize the exit point.
    Say a Wormdrive is only accurate to 0.01% of the traveled distance. So a jump to Alpha Centauri could easily be off by the Earth-Mars distance.
  3. Wormgates can be relatively close to each other, in orbit.
    Something about the calibration sets them apart for paired connections, maybe. So if there is no Wormgate between A and B, it is much cheaper to take the A-C, C-D, D-E, and E-B gates if such a chain exists.

This gives you:

  • Civilian/Commercial Gate Craft
    Freighters, passenger transports, and the like. They travel only through gates, with relatively weak maneuvering thrusters to get from gate to gate. By far the cheapest mode of travel, a can with a little flight deck attached. Endurance might be measured in hours; passengers get seats rather than cabins. No military use, unless both sides of the gate are firmly secured.
  • Civilian/Commercial and Military Wormdrive/Warp Craft
    Offensive warships and scouts. They can use the Wormdrive to travel to unexplored or hostile systems, and maneuver there with Warp. The most expensive craft, and those with the smallest payload, since they have to carry two FTL drives and usually long-term life support. They can use Wormgates, but they are not competitive if the trip is only from gate to gate.
    A special subtype are Wormgate emplacement ships.
  • Civilian/Commercial and Military Warp Craft
    They can travel long distance by Wormgate, and insystem by Warp. Cheaper than the combination designs above, so they get better payload and/or better warp speed. A defensive space force has just these, since they carry more bang for the buck.
  • Wormdrive-Only Craft do not exist (or they are prototypes)
    If Wormdrive is "easier" than Warp, then Wormdrive craft might be required to deploy Wormgates to a new system. After the arrival scatter, they spend a long time traveling sublight to the planet or whatever.

Lots of good answers here, but I can provide an overview with less text.

Wormgates are easy.

They require infrastructure. Think of this as your railroads: high infrastructure cost, limited access points, but cheaper transport cost. They would be an industrial staple. You have to get someone to the destination and build the gate on the other side, but once you build it, you can send ships without having to build an expensive wormdrive or warpdrive into them.

Wormdrives vs. warpdrives

You have to build limitations into them. This is part of your job as a fiction writer. What are their energy requirements? What are their limitations in respect to obstacles? How far out of a gravity well do you have to be to use them safely? What is the spin-up time for a wormdrive, and how many jumps do you get on a tank of gas, and what is the range of the jumps? How often do you have to stop for fuel for a warpdrive, and how easy is it to get?

The relative efficiencies will tell you if you have a situation where a ship might have both. Maybe a small warp drive for moving around a solar system, and a jump drive to get between stars, or a large warp drive for exploring deep space (or a nebula), but a smaller jump drive with a really long spin-up time that's just designed to get you there and back. Maybe bigger versions of both, but very little room for cargo or crew.

Story over realism

Decide what the balance is for the story you want to tell, what limitations might provide the best dramatic points for your story, and run with it.


Energy usage

To send smaller ships, the Energy needed can be easily provided by the ship's own power plant. But as the ship size increases, so does the power draw, but exponential. A ship twice the size needs quadruple (or more) power output for the same jump. Power plants however scale linearly, so that there is a maximum ship size that can be used with its own worm engine.

The maximum worm engine size for a given reactor is what gives us the upper line of military craft, which encompasses anything from a small destroyer to a carrier. With some ingenuity, the carriers might even dock their escorts to take them along in a jump, using the oversized power supply of the docked ships to give the needed power to take them along with the main ship's worm drive.

However, this size sweet spot of where your ship starts to suffer from taking up too much space for drive and engine means that cargo ships would have significantly impaired cargo capacity. To avoid that and have maximum cargo, large vessels use static, external drive generators, the worm gates. Because a gate only moves the ships, not itself, it can be almost entirely generators to send the massive cargo ships through space.

minimum size requirements

A stable worm jump requires a minimum ship size that is above the average interplanetary shuttle size. As a result, small shuttle routes rely on more compact but slower warp engines to get to work gates that catapult the ship forward and take the last leg by warp again.

Worm drives and gates are disturbed by gravity fields

To open the wormhole with a worm drive or gate requires fine calibration. Gravity fields need to be very consistent and barely changing to allow the proper calculations to be done in a manageable time, limiting their use to the outer periphery of solar systems. However, their speed advance over mere warp means that most ships with warp use gates for long legs, cutting their travel times from months to days.

  • $\begingroup$ I also considered that warpdrives have an advantage as they can be used without specific destination coordinates and can be activated and deactivated at any time. But to counter their advantage they are slower then wormdrives and easily tracked/detected. But warpdrives seem to become redundant if wormgates are easily accessible. $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 10:48
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    $\begingroup$ Worm gates might require distance to a star that makes them unattractive without warp - it takes month out there without $\endgroup$
    – Trish
    Commented May 5, 2022 at 11:16
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    $\begingroup$ Worm gates are like airports. Expensive to build and maintain and undesirable next to settlements due to pollution (probably radiation but maybe some matter as well). There aren't that many of them and you'll have to pay a substantial fee to use them so for small distances or when time isn't important, warp drives are used. $\endgroup$
    – xyldke
    Commented May 5, 2022 at 12:00
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    $\begingroup$ @xyldke But we can't forget ship mounted wormdrives are also available, so warpdrives would have to be preferable over those as well to be used instead of worm gates. But I suppose wormdrives are essentially your own personal wormgate so are probably out of the price range of most? $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 12:13
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    $\begingroup$ @Stargazer If worm gates are expensive to build and maintain, so might wormdrives. The risks and limitations that other answers have mentioned could also apply, which means you need skilled pilots to work them. They are thus not affordable for the average person and not economical for most corporations. EDIT: I see, you've already come to that conclusion! $\endgroup$
    – xyldke
    Commented May 5, 2022 at 12:25


Other answers have touched on this but I thought it bore some further discussion: the main reason you still have warp drives at all is they they are a 100% safe means of travel. "Space weather" (flares, supernovas, black hole collisions, etc) can cause all kinds of havoc on interstellar travel, especially [I am speculating] on worm holes.

Worm hole calculation must be very difficult. You would presumably be mapping out gravitational fields between A and B but those fields are constantly shifting and you can never be sure what they are right now (you can only base it on what you see right now, which is, thanks to the speed of light across long distances, very dated information).

If you encounter something in your warp drive, your errors will be very minimal as you only need to calculate millisecond by millisecond based on local conditions. Errors on worm drives could surely be rather enormous. On the other hand, wormhole travel should be instantaneous -- you are linking A directly to B so you simply fly through and you're there. So very long distance exploratory travel probably uses worm drives to get to the general area (likely with some forward probes for safety) and then warp drives for the fine details.

Worm gates presumably make wormhole travel safe and predictable, perhaps acting similar to a lightning rod and "attracting" the destination wormhole to that gate, in addition to allowing plain vanilla ships (such as cargo haulers) to make the trip without needing their own special drives at all. Although maybe once in a while, weather conditions are sufficient to cause a wormhole to miss its intended gate and either open to some random location or end up at the wrong gate... (This probably presents minimal risk, since they could open the wormhole at the source, send through standard radio queries to make sure it has connected correctly, then green light the traffic. If conditions have gotten off enough that the gates are not connecting, then they may have to disable them temporarily while they figure out what has changed and recalculate.)


It all comes down to money - abstracted, in this case, as energy cost.

A wormgate, while a permanent portal to another location, will transport anything any everything through it, like a regular door. That means you can't have one in your living room and one at Grandma's, because Grandma lives near the beach and you live upstate - the pressure difference would mean there would be gale-force winds pouring through the gate at all times. The safest place to put a gate is in space. Vacuum is vacuum, give or take, so you won't be paying the energy cost of transporting more than a bit of space dust. Wormgates are highways, designed for high traffic flow of otherwise normal vehicles, between well-known locations. Gates need to be linked, because each gate supports its end of the wormhole - only a stabilizing structure pouring energy in keeps the wormhole stable.

A wormdrive takes the same computing power, energy, and resources as a gate, but since the wormhole is single-use, it doesn't need a gate on both sides to maintain it. It's more like crawling through a fabric tunnel - you lift the bit you're in, and the rest stays closed. Ships with wormdrives are supertankers, giant cargo ships, military ships, and freight trains - best used to transport huge amounts of material or people to locations that may not have wormgates, or in such quantities that the sheer mass would would clog up a worm gate for a long time. The military uses them because, frankly, the military doesn't care how much it costs to drop a frigate behind enemy lines; big shipping companies use them because they can transport the wealth of a large country from A to B, and profits from the trip dwarf the costs. A family or exploration team would balk at the exorbitant energy cost.

The warp drive is akin your average truck, family car, or ATV. It's not as efficient as a wormdrive, but it's a whole lot cheaper when you're only hauling a handful of people. It has a low energy cost, it can be turned off when not in use, and it's reliable, especially out where it's not cost effective to set up gates. If you don't live near a big population hub or tourist destination that would have a gate, and you don't have the budget of a small country to run a wormdrive, your best bet is the slower, clunkier, noisier, but vastly cheaper warp drive.


You can fix anything with economics. A technologically inferior method is likely to persist if it cheap enough compared to the alternatives.


A wormdrive requires the exact "coordinates" of its destination to be known. This might be more involved than mere position. Gravitational influences at all points along the route, because they bend spacetime? Even tiny errors become significant when propagated over hundreds of lightyears.

So you need warpdrives for exploration and surveying / route maintenance. You also need minimal ones on every ship for getting out of trouble if the wormdrive delivers you a lightyear away from your intended destination.

As for wormgates, they need expensive infrastructure at both ends. You can't go anywhere new. Also you can't economically justify them on routes that don't see a lot of traffic. Or you can make up other reasons. But they might just be the Airbus 380 of the interstellar transport market: too expensive in all but a few special cases.


My question is can wormdrives, wormgates and waprdrives in this scenario exist without making any of them redundant/obsolete?

Yes, because each of them has different use cases, requirements and limitations.


A warpdrive-powered ship is ideal for short distances, from in-system travel to nearby star systems. It's a slower trip but much simpler and more maneuverable. Just point your ship in the general direction you want to go (within a few arcseconds perhaps) and go to warp. If your aim is off you can drop to normal space, reorient and then go back to warp. No clever, time-consuming calculations required, and basically anyone can be trained to fly the ship in a couple of weeks.

The other advantage is in power usage. A warp bubble takes a fair amount of power to establish, and the total power usage over the trip may be a little higher than a wormdrive, but the peak power usage is significantly lower than either of the other two. That means you can save a lot on the power system.

The main downside of course is that warp is (comparatively) slow. It's going to take days or weeks to reach your destination, but for cargo or low-priority passenger transfers that's unlikely to be important.


These drives are the best option for fast travel between arbitrary locations. Punch the destination coordinates into the navigation computer, give it half an hour to calculate the exact parameters of the required quantum field geometry, punch a hole in the fabric of reality and next thing you know you're on approach to Spica III in time for that big conference. Assuming the navigation computer is functioning perfectly and your sensors have correctly locked the navigation references.

The main downside is the massive amount of power required to actually open the wormhole and hold it in place while you traverse it. It's a lot of power in a short period of time, which means you need a hefty power system. You don't have to generate the power all at once, you have time while the navcomp is running the field computations, but you'll need some really big accumulator banks to hold the power ready for breakthrough.

The big downside, apart from all that waiting for things to charge and such, is that the power requirements increase exponentially with range. There's a sweet spot beyond which it's cheaper to make multiple jumps, and most wormdrive ships won't have power systems capable of going much further than that. Still faster to travel than warpdrive, but it might take days to travel to distant parts of the Empire.


As fixed structures gates can have much larger power generation and storage than ships could reasonably carry. And since both ends of the wormhole are held open by a gate mechanism the power cost of both establishing and maintaining the wormhole is greatly reduced. This means that gates can be used to travel much greater distances than wormdrives, with the added bonus that ships don't require special drives to traverse the wormhole. And because the positions of the other gates are known ahead of time the calculations required to generate the wormhole are much simplified.

The advantages here are pretty obvious. Lots of options for long-distance travel that other drives can't match, and you can funnel a fair amount of cargo through the network fairly quickly. So of course the downsides are kind of huge. The further the distance between gates the shorter the wormhole's duration, but that's not a significant issue unless you're trying to get a whole fleet from one side of the gate network to the other.

The main downside is the recharge time. Each of the gates in a connection will be discharged after the wormhole collapses and will need some time to recharge before it can open another wormhole. Depending on the generation capacity this might be an hour or more, and the gate is useless during this period. Attempts to connect to the gate during this time will fail, with the originating gate using up a portion of its stored power in the attempt. If you have three or more gates to work with you can keep a target gate out of action basically indefinitely. Great for system interdiction, if you're that way inclined.


can wormdrives, wormgates and warpdrives in this scenario exist without making any of them obsolete?

Cheap, fast, no infrastructure required. Pick 2 out of 3.

Gates probably require a large upfront cost but transit is very cheap per ship. Probably gates are not alone in the system - they form an interstellar highway system allowing to fast travel for vast quantity of good and people. Most people/companies (depending on how affordable spacecraft is) on core systems don't own FTL vessel. Why would they if they can reach everything (outside of backwater systems) with traditional ones and gates? It's like owning 4x4 when you live in a city.

Wormdrives form a second tier system. They require no upfront cost and are fast. But cost per-ship is probably much higher so likely they are used for large ships (economy of scale) or for time-sensitive cargo (military/government use etc.). This may be how many people travel off the core systems (depending on price).

Warpdrive is a tertiary system. Good for cheapest routes allowing connecting systems to which it would be uneconomical to maintain other routes or as second tier system for less time-sensitive cargo. If you ship bulk goods they will be shiped by warpdrive. If you have a more price sensitive passengers they will pick warpdrive.

How could I justify why wormgates need a destination gate? And are there any other redundancies or more efficient ways to use this tech I have overlooked?

Power requirement increases superlinear with distance. However if you link two gates you can lower energy consumption. However they need to have a pair to complete another side of connection.

Also the second gate signifies where the exit will be. Since gates are in busy systems you need to have a place where ships can queue and avoid traffic. You probably have an equivalent of Bravo airspace.


Well, from a purely technical perspective, jumpgates have an obvious use a main axes for commerce and migration. First, existence of two anchor points, an entrance and an exit, means more stability and thus the ability to maintain the wormhole over greater distances. That gate networks are well known makes it easier to manage them and avoid accidents like from different origins trying to jump at the same coordinates at the same time. Second, every vehicle is a compromise : for a given size you want to put the most stuff inside yet have it use a little energy as possible. Wormdrives take space, cost to maintain an draw power. All of that can be allocated to, say, more cargo or passenger space! Makes Jumpgates more cost-effective! Their downside, however, is that they still cost an arm and a leg to make! And even more to maintain! Obviously you're not gonna use them to connect every planet in your empire, you're keeping their use for the more-traveled paths, where they're the most cost-effective.

Wormdrives however have the ability to jump from wherever their current location is, as long as they know where they're going and that it's not too far for their drives. Even if it is, they can leapfrog their way. This will make them very effective outside the gate network and extremely useful when required to travel outside of said networks, like a hidden military base that's really accessible only if you know its exact coordinates.

Warpdrives, at first glance, may seem inferior. But, in truth, they're ubiquous. Sure, they're the slowest method and wormdrives also give freedom of navigation, but they're cheap! They're the oldest, mature tech of the three. Sure, it ain't shiny, but they've become very fuel efficient, they have plenty to failsafes against any possibility of crashing (at ftl speeds you can't rely on the pilot's reflexes after all) and they don't require any precise calibrations based on ship's mass like wormdrives. Plus, unlike wormdrives, which are highly regulated and whose tech is kept a state secret, anyone can learn to make and maintain their warpdrive!

From a political perspective, the freedom of wormdrives is risky to governments as that makes them harder to control. Sure, warpdrives gives a similar freedom, but at least those are slower and much more easily detected! Obviously smugglers and other people whose activities run afoul of the law would love to get their hands on them, but they are highly regulated and difficult to obtain.

EDIT: Didn't notice the question changed a bit. About exit wormgates. It's well known they're necessary, for stability and all that. But, funny thing is, it is possible to use wormgates without one! People suspect it, but with governments keeping wormdrive tech secret, no one really knows for sure and no gate was ever used that way, that we know of... But even if they knew, wormgates have been designed to work in pairs now. Trying to open a wormhole to a place without an exit wormgate to share the power load? At best nothing happens, at worst your ship ends up God knows where...

  • $\begingroup$ I could agree with and use pretty much all of what you have said here, especially love the view on warpdrives being an old and workable technology vs wormdrives complexity and secrecy and the political perspective. I would love a distance limitation on the wormdrives but am having trouble deciding why they have these limitations? $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 13:24
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    $\begingroup$ @Stargazer The first thing that comes to mind as a limitation, perhaps more a drawback or danger of the WormDrive, is that you a very limited scope of knowing what your environment will be at your emergence point. Some things that I didn't include was, is there a requirement of a speed at which you must attain to enter warp or worm drive? do you retain that speed at emergence? There could be debrese or a ship there and WHAM!. Even the star itself could have gone nova in the 12.5 lightyears' since you started the jump. Maybe the only recourse to jump to 40+ AU away from the solar disk and hope! $\endgroup$
    – Gillgamesh
    Commented May 5, 2022 at 14:04
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    $\begingroup$ @Gillgamesh I could say there are certain areas of space (around populated systems) that are well mapped and others not so much known as wild space and you could travel through wild space safer with warpdrive scanning your surroundings in real time with the ability to respond or you could make a blind jump with a wormdrive and hope as you said. So maybe the distance limitation is down to navigational data and/or the distance of space your ship can safely scan before a jump? $\endgroup$
    – Stargazer
    Commented May 5, 2022 at 14:13
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    $\begingroup$ @Stargazer There's a few ways to limit wormdrives. You've already brought up one of them, wormhole stability. Since a ship needs to open a wormhole to specific coordinates, that means you better be sure your wormhole is stable enough for the entire trip, or else... The other is power. Opening a wormhole doesn't just cost power, it costs it upfront. Unlike a warp drive, who just steadily drains energy when active, a wormdrive needs to be able to muster most of the energy used upfront, or no wormhole. wormgates are fixed, they can stack huge capacitors, but room is a premium in ships $\endgroup$ Commented May 5, 2022 at 14:41

@JohnO has the right start, but there is a way to make all three technologies simultaneously viable and important.

Here are the principles you need:

  1. To make a wormhole by drive or gate, someone needs to have gotten to both of the ends of the wormhole and spacetime mapped them in sufficient detail sufficiently recently to make a wormhole.

  2. Wormholes are unstable (as you mention in the question) and can only last a few minutes.

  3. There isn't FTL communication other than through wormholes or warp mail (you stick a message on a ship that goes to warp).

  4. All such drives are non-negligibly expensive.

Given this, here is what we end up with:

  1. Wormgates are for high traffic routes and for small ships. Wormgates are permanent stations that are constantly doing spacetime mapping of their area and opening wormholes to other wormgates to transmit that data so that the network stays in sync. The core gate network would be small due to the quadratic number of upkeep wormholes needed to maintain it (each gate needs to stay up to date with each other gate); the rest of the network would be connected by a hub and spoke model (much like modern airports). Not all ships have native warp/worm capabilities and those that don't need to rely on the gate network for long-distance transit and may need to use multiple gates to get places. In modern terms, this is the equivalent of flying commercial.

  2. Wormdrives are for big ships traversing lower traffic routes to settled destinations. If you want to get to a wormgate without needing to go through multiple layovers and you have a wormdrive, you can just buy a spacetime mapping of your destination from the local wormgate (which they sell for much cheaper than passage itself). Note that you can typically only wormdrive to places in the gate network, unless you have the assistance of warpdrive shps (see below!). In modern terms, this is the equivalent to chartering a private plane.

  3. Warpdrives are needed when there aren't gates maintaining an FTL link between the places you want to go. Someone has to get between A and B sufficiently fast enough to have valid mappings of both A and B and be able to wormdrive between them. Thus, a warpdrive can get you to arbitrary places not on the gate network given enough time. In modern terms, this is the equivalent of driving.

  4. Combos: Warpdrives are also essential for expanding the gate network or allowing temporary routes between places. There is going to be some max distance on this, depending on how fast mapping data goes stale and how fast warpdrives are, but that formula gives you a distance of X lightyears that you can send a warpdrive + wormdrive scoutship that can then wormdrive back with mapping data and allow for a temporary wormhole transit between two places. That temporary wormhole can then be used by the same scoutship to go back and forth between those two spots to keep up to date mapping data for a longer period, which could eventually allow construction of a new wormgate.


Babylon 5 does this - their jumpgates are fixed systems that allow ships with no/limited hyperspace capability to enter hyperspace, and act as part of the navigation beacon system. Warships and some other ships have organic jump capabilities. 2 factions have their own jump tech (the Shadows simply phase in and out of it, and the thirdspace aliens have their own hyperspace-like-dimention).

Organic jump is "heavy", power and cost expensive, and you don't really want to throw it on say a grain freighter, but a destroyer might find it tactically useful and worth the cost.


Warpdrives don't require destination coordinates. They can be activated and deactivated at any time to move continuously through space. But they are the slowest of the three, and are easily tracked and detected.

While slow, you can use this for initially plotting out space since you can go anywhere and get back. These would be useful in exploration and expeditionary ships, or for short range tactical jumps. These would also map out space for the other 2 technologies, so you could have detailed spacial maps for jump calculations.

Wormdrives require precise destination coordinates. The Wormdrive mounted on your ship creates a temporary traversable wormhole that starts in front of you and ends at the destination coordinates.

These would be the 'classic' jump drives - mounted on warships and ships that need to go to mapped locations that are off the main spaceways. You can jump anywhere mapped, and out. These would be less flexible than your warpdrives, but more so than fixed gates

Wormgates are two wormdrives linked end to end. You need one ship at the start of the wormhole and another one at the end.

These would be what you have on the principal systems of an interstellar polity. Since they're fixed, mass, cost and power are less important, and they allow ships with no jump drive to travel between points. They'd allow simpler low cost ships jump travel and as such be the backbone of the civilian and peace time military transportation network.


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