I've never played the games, but I've read the wiki a fair few times, and been around when ME's talked about so I have
an idea on what I'm talking about here...
According to said wiki, the Normandy SR-2 has a fusion power plant, and anti-photon thrusters.
Further reading makes me think that it may be another case of BioWare not being entirely sure what they were talking about and so added 'cool stuff' in... I'd like someone else to double-check, but I think that this is probably more likely to be what's the actual case... Okay, I looked further, and they
may actually have thought this out!
The Normandy's Fusion Reactor is just a standard Sci-Fi Fusion Reactor. The availability of Eezo probably has some disadvantages, and some advantages. In other words, ME Fusion Reactors probably benefit from the use of Eezo to create something similar to 'gravitic pinches/clamps' and the like... which basically work by subjecting the reaction mass to immense pressure, thus reducing the temperatures you need to have the reaction mass react to being fusing from the
ludicrous temperatures you need in modern thoughts on fusion reactors... Which both increases how much energy you gain from the reactor compared to how much spent (Unless the method you are using to create the 'pinching' is ridiculously energy inefficient, in which case
why are you using it?) and decreases the size/cost/maintenance requirements, etc...
And the Antiproton thrusters are one of
three types of main propulsion systems that the ME Races use.
The first are Ion Drives.
Extremely energy efficient but pay for that efficiency with the fact that they take a
looooong time to build up speed, aka extremely low thrust. On the other hand, this means that fuel costs are basically null, as long as you don't have to care about how long it'll take something to get somewhere. So Ion Drives are basically used solely by automated space- and starships. Things like Automated Cargo Barges, where you set up a loop where they are loaded with one thing at Point A, travel to Point B and swap the cargo with a new thing and then travel back to Point A, swap it for the original thing and start the whole loop again. Basically, forget about using it on manned craft, but it's great for merchants and companies setting up cargo transportation from their mines to the factories.
Then you have the Sci-Fi staple, the Fusion Torch Drive. It's... basically what happens when you have a fusion reactor that produces a lot of
really hot plasma as a waste product, and you need to do something with it. Really hot plasma you say? Can't keep it on board? Why, it's perfect for shoving out the back of an engine and pushing the ship along! Great thrust, uses up something you already have to have on-board your starship, doesn't really add any new systems and if you need more fuel, just suck up some gas from a Gas Giant. Not like there's a shortage of
those around. Perfect for civilian craft. In short, it means the ship has two fusion reactors, one is tapped for power with the waste fused plasma being added to the exhaust once as much power as possible is tapped from it (Probably, I'm not certain), the other is not tapped for power and instead has all that nice, hot, highly energetic, and thus high thrust providing, plasma sent straight out the back of the ship, pushing it along.
Finally you have the Antiproton thrusters mentioned earlier... And it's kind of mis-named. What they actually are, are more like combined Annihilation/Fusion Torch Drives... They're basically made by taking a civilian Fusion Torch, making it the best Fusion Torch you can get... and then throwing a continuous stream of anti-protons into the reaction chamber of the fusion torch. This produces
even more energy! Thus more thrust, allowing warships to manoeuver and travel faster. Great things for a warship! Only problem is you need to either have an extensive industry harvesting natural antimatter particles generated by planetary magnetic fields (of which only Gas Giants probably provide anywhere near useful quantities) or you sent up an even
more extensive industry that collects sunlight from a star (really,
really close to the star too, you need an
enormous amount of power) and then another industry dedicated to taking all that free power and shoving it into particle accelerators to artificially generate antimatter.
Advantage for the second method is it's a
lot easier to scale up as demand for antimatter increases, but also a hell of a lot more expensive. Both methods also effectively have 'Shoot Me Now!' signs hanging from them during war, and they aren't exactly
easy (or even possible for the second method) to move to somewhere else when the shooting gets close.
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As for what we have right now in the quest? I'd say that, as Poptart said, we have less powerful, and less efficient, also most likely larger, fusion reactors and fusion torches powering even our warships. I wouldn't be surprised if the Salarians are playing with using antimatter at the moment, but nowhere close to the sort warships had in the ME Games. I figure that say, by the time of the Krogan Rebellion, Antimatter 'emergency thrusters' might be standard on warships, but not much more. And those might disappear as well as infrastructure gets destroyed and antimatter gets more expensive. By 'emergency thrusters' I basically mean an antimatter explosive on top of a specially reinforced section of the ship's hull. Need to suddenly move your ship because say, that Krogan heavy cruiser's about to line up it's spinal gun with you? Set off one of the 'thrusters' to get an immediate, and entirely unpredictable (For the enemy only, I hope...), adjustment to your course.
Give it a few more centuries (at canon-ME technological progress) and you'll probably see baby versions of the anti-proton thrusters appear. By the time of the Geth, you'll probably have something pretty darn similar to ME Games anti-proton thrusters, just less powerful, more expensive, etc, etc...
And do note Poptart, that the reason that warships are the only people that use antiproton thrusters in the lore, is probably a generalisation, and that other than a bare handful of other roles,
they are the only practical users of that sort of drive...
At least until a breakthrough is made making antimatter a hell of a lot cheaper to produce, and someone figures out how to make the heavily increased maintenance requirements of the antiproton thrusters reaction chamber/drives/etc significantly closer to the requirements of normal fusion torches. After all, which are civilians going to use? The thing that gives the best performance but pretty much requires a multisystem government's income to construct and maintain the infrastructure to keep the engine running, not to mention a hell of a lot of maintenance to the engine itself... Or the thing that's 80% as good, can be refuelled anywhere and has no special requirements in maintenance or construction... and needs a lot less maintenance as well...
Hell, even multi-system civilian companies would take the second drive all the time. Means they earn even high profits, and the performance lost isn't particularly noticeable when your competition's using the same engine.
EDIT: And I completely forgot to mention how the fact that the antiproton thrusters need antimatter to work run into
legal problems being used by civilians. An entirely
different set of difficulties unrelated to the economical difficulties of civilians using them. I mean seriously, it's
antimatter! Do you think that the Council/Council Racial Governments are going to let just anyone get their hands on kilograms of antimatter?
Hell no! I mean, we already know the Turian Hierarchy has a separatist terrorism problem... due to the fact that they flew a
starship into a populated planet... How do you think those guys would react at the possibility of getting their hands on a kilogram of antimatter, even if they needed to smuggle it from outside the Hierarchy...
I know what
I think their reaction would be... Absolute... Hysterical... Glee! Well, once they've figured out a way to conceal the magnetic trap that holds the antimatter from detection at least. Doesn't even need an independent power source, just a battery that'll keep the magnetic trap powered for long enough that they can sneak it through the defences into the target zone, get the hell out of there and off that planet, and then wait for the planet-shaking Ka-
BOOOOOM!!!!!
And the Council Races are the only ones that can really provide it on the needed scale... The Canon Terminus runs into the problem of all those fights blowing up the stuff building the stuff that gets the antimatter. And if anything
is kept intact, I wouldn't be surprised if it encounters a terminal visit from a SPECTRE one day soon...
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Whhhhyyyyy did I decide to actually research all this and write up a post?
Whhyyyyyyy??? I thought it would only be a 300 word thing at most! Instead it's
this monster... Oh wait, it was a starship tech discussion,
Problem solved!