In many sci-fi movie tropes, we see gigantic spaceship using tractor beam to reel in smaller spacecraft. Usually in every scenario that is being played out the smaller spacecraft is trying to flee away from the huge ship and we see the tractor beam eventually overwhelm the smaller craft in terms of power, amusingly the same giant spaceship had the capability to transport crews between 2 points, from ship to ship or ship to surface of a terrestrial planet, etc. Wouldn't it be easier for them to teleport security personnel or droids onboard the smaller vessel than wasting time trying to pull in the entire defiant vessel itself? I like to know why would tractor beam be used instead of teleportor obviously the latter seems to be more cost and time saving?
Why would you risk boarding a spaceship of which you know nothing (crew count, internal arrangement, mode of operation) and expending your crew, when you can much more easily bring it under your scanners for studying it?
Moreover, any casualty on your side means the potential for an unknown item being beamed back to your ship. And since that time when that alien got an exploding nuke back from the basement of the pyramids, the whole space knows it's a no no!
Teleporters are almost invariably portrayed as a rather easily disrupted and quite limited technology.
Probably because if they weren't, they'd be awful for story-telling.
Here's a list of reasons why I'd rather drag a smaller ship into my cargo hold and breach and board it than simply teleport my troops aboard..
I don't know what the internals of that ship look like. Even if I have the full design-specs for the class of ship, for all I know, they've lifted the deck-plates 6 inches up and all my boarding crew will find themselves chopped off at the ankles or embedded in the deck.
Sensor jamming, transporter-scattering, shields blocking or just plain weird hull-materials may make it difficult to teleport aboard a ship without its cooperation.
Transporting aboard a moving target comes with a whole bunch of risks regarding accuracy of the transporter. And while I don't mind if the molecules in a piece of hardware get a tiny bit scrambled, "Transporter Sickness" sounds like an awful way to die.
Even if everything goes right, you now have soldiers somewhere in the middle of an entire ship full of enemy combatants, surrounded on all sides with no retreat possible and no sense of whatever internal-security threats they might encounter.
This is not an ideal situation for a soldier.
When it comes down to it, docking and boarding is better, safer and more efficient.
your teleporter needs some time to calculate each teleportation. by the time it is finished doing the calculations both ships would have moved in some unforeseen direction. so if it were to teleport you then you'd just end up somewhere in space. or worse inside a wall.
so as a doctrine it has been banned to teleport to any craft that is still using it's engines.
This is like asking "What is the purpose of a screw driver when I have a hammer in my toolbox?"
Tractor beams do things that teleporters can't.
- Tractor beams can manipulate much greater masses then teleporters Due to limited data processing, energy buffers etc.
- Tractor beams can manipulate objects external to the ship and keep them external.
- There are literal massive energy consumption differences. The cost of teleporting one person would be comparable to tractoring a whole ship for many minutes.
- Tractor beams are simpler thus less likely to be blocked by technical solutions.
- Less ethical issues. Teleport creates a perfect copy and the original is destroyed. So avoiding the whole premeditated murder/suicide thing.
- Legal issues. Teleporting crew on board might be act of war, where as tractor beam might not be as clear cut/not an act of war. Perhaps closer to the difference between detaining a person and searching their possessions.
If a ship can't block teleporters they will be destroyed in combat.
Any ship that faces teleporter equipped enemies must be able to block teleporters or risk complete ship loss.
Teleporting is essentially the act of random access placement of antimatter level weapons into/on the target.
Being able place 100Kg of energy/ on the bridge, engine room or munitions storage of an enemy ship should have obvious strategy implications. Teleporting bombs would have much greater range then transporting people. Since keeping the destination a functional person is much different then dumping 100Kg of photons.
So a not being able to use teleporters against a ship is very plausible.
Ultimately however, it is what will make a more interesting story from the authors perspective.
In the Star Trek universe teleporters solve the problem of minimizing boring screen time on shuttles. That is, teleporters exist to make a more watchable show.
Because you make every effort for teleporters to not work.
You can beam/teleport over a crew because you want to capture the ship, but the moment you have that ability then they can teleport stuff as well. Some easy ways to use teleportation:
- beam the shielding plates off of the enemy reactor
- beam random parts of the bridge to your cargohold, you are bound to get pieces of the controls and computers.
- Beam out the fuel of your enemy, for funsies you can beam it somewhere else on the same ship. Even if you dont ignite it or whatever its not going to be a pleasant experience
- beam the enemy weapons off
- beam large parts of the atmosphere out of the enemy ship
- beam nasty things back, like bombs, nasty gasses, ignited fuel etc.
- beam "innocent" things over like a steel plate into a corridor, a wrench inside the antimatter feeding mechanism, some quick drying glue into the coolant lines etc.
Now someone may have the bright idea to create protections against this like shields and interference fields that you can drop for a fraction of a second to teleport your own into the enemy without them being able to teleport back. This still has a massive problem: since teleportation inside the smaller ship is possible (you've just proven that by teleporting people in) there is nothing stopping the people on the small ship teleporting anything you send over either. You can teleport the boarding party to the brig, out to space or in pieces to the waste processing facilities. Assuming you dont just take their weapons and teleport some restraints to their arms and legs.
The end result is always the same: you dont want any teleporter to work in a combat situation, ever. The fact that teleporters exist in sci-fi and still play barely a role in combat is ridiculous.
Ships are life support systems designed for a certain number of individuals plus a small headroom for emergencies. If there are no close habitable planets, taking a lot of people onboard means renouncing immediately to that headroom and a second emergency could put the crew of the rescueing ship in danger.
Do you have any idea how much energy it takes to teleport something?
Tugging a ship requires very little energy - you are already powering your ship to move, you just have to apply the additional power necessary to haul the additional mass along with it, attached by whatever 'tractor beam' connection is being used.
Compared to a teleporter, which has to produce E = Mc^2 minimum in order to disassemble and then re-assemble that matter elsewhere.
Clearly, the tractor beam is a better choice for more massive objects. While teleporting is best reserved for smaller objects where that conversion is much less expensive.
Size and vulnerability
First, while a ship may be relatively small, it's still a ship. That's still pretty big. The room that a teleporter resolves into may simply be too small.
Second, once another ship has materialized inside the larger ship, they have a little ship on their inside. Usually all the dangerous, antisocial parts of a big ship are designed to point outward. The big ship has its mean bits pointing outward toward space. The little one has its nasty bits pointing outward toward the big ship. Anywhere they fire is going to damage the big ship, which presumably will have very little ability to respond. In fact, the instant the little ship has been teleported inside the big one, the best thing it could do is immediately teleport the biggest, meanest remote-controlled bomb it has to some random place inside the big ship, and then start firing in any direction that doesn't damage the teleporter. The big ship then teleports the rude little ship back into space. The little ship then detonates the bomb, and the little ship quickly becomes the biggest intact ship in the area.
It steadies the target ship and makes its relative speed to you zero. It also pulls the target in closer.
Both of these things make it easier to target the empty spaces in the ship (to prevent finding out what happens when you teleport someone into a bulkhead or a chair). This decreases the manpower loss of boarding the target.
The target will probably be making small, fast, random movements to make safe teleports harder. Being held in a tractor beam will dampen these movements. It will also draw the enemy closer giving less signal travel time to make sure that the spot that you targeted is still there when your boarding party materializes.
As an aside, tractor beams also mimic the grappling hooks and ropes that were used in the age of sail (which everyone seems to like to mimic).
There's something you need on that ship that you can't simply teleport
Maybe you need the ship itself. The craft's hull is made of a never before seen alloy rendering the ship nearly undetectable. It's almost a miracle you managed to notice it in the first place. You'd love to take the ship home for reverse-engineering and analysis, but it sadly won't fit inside your cargo hold.
Or maybe you just need the ship's computer, but have neither the tools nor the personnel to safely extract it. Teleporting that computer into your ship without properly disconnecting it first might destroy the very thing you're trying to recover.
Possibly that teleporting somewhere would require a relatively constant distant between sender and receiver. With a tractor beam you can first hold the smaller ship in place and then teleport to it.
Plus that if that smaller ship has its engines on, you probably should not try to teleport it to your cargo bay.
Attitude of the giant spacecraft's commander- sending a small team possibly to the wolves is too nice for him say look at the Death Star pulling in the Millennium Falcon- fits with Darth Vader's personality to grab a whole ship and drag it to him.
Internal infighting is another reason- the commander doesn't have real control over the internal organization-its just too big and just look at arms of the military infighting. the space tractor group is always competing with the transporter beam group so show how more awesome their tech is over the other guys. The tractor beam grabs the ship before the transporter beam group have got set up to send. Our tech is better than yours.
The is no Stopping in Space
In space, everything is constantly moving in an orbit around something. Even objects that are close together have slightly different orbits. This means that ships can drift apart or collide.
You could fire your engines to match their position, but that would be a continuous drain on fuel. It's much easier to just grapple their ship with the tractor beam and prevent any issues in the first place.