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Season 4 Episode 17: Midway.
Picture of partially-constructed Midway station

Why does it have two stargates? And how is that even possible, i thought there must be a huge distance between each of them to work; it would be pure chance which one activates when connecting to that place in space.

Is that just pure aesthetics to make it look cooler, or did i miss something ?

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There you go, I added the image. – Keen Oct 6 '11 at 14:20
Why have only one when you can have two for twice the price? – Xantec Oct 6 '11 at 20:00
concerning that minimum distance, in the final episode something like "When a Pegasus gate and a Milkyway gate are nearby, the Pegasus one takes precendence - it required quite a hack by us to make midway station work" was stated when the Stargate at the Hive ship is discovered – Zommuter Nov 11 '11 at 20:29

12 Answers 12

up vote 31 down vote accepted

I think Midway station ties the Pegasus Galaxy gates to the Milky Way Galaxy gates... Apparently the two gate networks weren't compatible so they needed to re-enter the system each way.

Additionally, it adds another level of security, so that in the event that the Wraith penetrate the Pegasus side, there is a chance to destroy the facility before they get to Earth.

If I remember right, the whole project didn't exactly turn out well.

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Yea, it ended badly because the wraith penetrated the Pegasus side and took over Midway Station. – BBlake Oct 6 '11 at 14:33
Incompatible gates was my first thought, but at the same time, that isn't likely, given they gated to Atlantis from the Milky Way in the first place. – eidylon Oct 6 '11 at 15:57
As I recall, they pointed out that the Earth gate recovered from the Antarctica outpost was the only one in the galaxy that could dial to Atlantis. So that would also seem to point to incompatible gate systems. – BBlake Oct 6 '11 at 18:21
Lets not forget that Jack went all McGyver on the gate before he managed to dial up, essentially hacking the crap out of it to get long distance! :) – Mister IT Guru Oct 7 '11 at 11:02
@eidylon You should ask that as a separate question. I don't remember entirely when "the fifth race" took place, but the Giza gate was at one point beamed up to Thor's Replicator-invaded ship, sunk into the ocean and recovered by the Russians. – Zommuter Aug 12 '13 at 9:26

I don't recall any incompatibilities between the two gate networks being mentioned in the series. And we do see direct galaxy-to-galaxy gate travel on multiple occasions throughout SG-1 and Atlantis, prior to the construction of Midway, which would seem to rule out this explanation entirely.

However, do recall that Midway is, well, the midway point on a series of gates that "bridge" the vast intergalactic distance between Pegasus and Milky Way galaxies. While not technically necessary (as we've seen Jack gate to the Asgard's home galaxy, and of course the Atlantis expedition got to Pegasus just fine without the bridge, among other examples), the power requirements of intergalactic gate travel are enormous -- remember how big a deal it was to get the Atlantis team there in the first place, and that for quite a while they had no way to get back, nor could Earth do it again to send supplies or even talk.

The gate bridge was built to solve that problem. Designed and programmed by Dr. McKay (probably with help, although you'll never hear him admit it!), it is most decidedly not the normal functioning of the gates -- each gate in series receives the matter stream, buffers it, and then sends it along again. This allows travel along the gate bridge with only the power requirements of normal interplanetary gate travel!

Midway serves two purposes stated in the series: Security (a little C4 in the right place, and the bridge is better than an iris!), and decontamination (why they never worried about this until they built the bridge though is beyond me...). We do see the security functionality in play when the station is taken over by the Wraith.

And now we're finally to the dual gates in Midway. Remember that the whole bridge is a non-standard re-jiggering (that's the technical word!) of the normal gates. Basically they've been reprogrammed by McKay et al to function outside of their normal parameters. So the gates could do whatever he wanted them to! It seems that the gates at each end of the station were "hard-wired" to only be able to dial the next gate in the bridge. Ditto each gate in the bridge -- depending on direction of travel, each gate is hard-wired to dial the next in sequence. Thus the closeness of the two Midway gates is irrelevant -- McKay just programmed them that way. It wouldn't be the first time SGC personnel have tinkered with the programming of the gates, although for once it didn't cause more problems than it was meant to solve!

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Of course McKay had help, it wasn't called the McKay/Carter Intergalactic Gate Bridge without reason. Also, the gate's weren't hardwired to only go to one gate on the other end, but the macro McKay wrote (and the only one used by the Tau'ri) dials Atlantis or Earth, someone else could rewrite the macro to go anywhere they want. – dkuntz2 Oct 12 '11 at 1:28
@DKuntz2 The McKay not admitting to help bit was a tongue-in-cheek jab at his rampant egotism, sorry that wasn't clear. And you're right, the macro could be re-written, but my understanding is that each gate in the bridge is basically at the maximum range of its neighbors, meaning that while technically the gate sequence macro could be change, in actuality there's really only one place you can go. Admittedly, though, I don't think this bit was ever discussed in-universe. – Kromey Oct 14 '11 at 0:51
What I mean is that if someone rewrote the macro, they could get to any Milky Way or Pegasus gate they want, which was both discussed and explored in Atlantis (in one case Carter and Lee gate to a planet closest to where Atlantis last was (in Adrift)). – dkuntz2 Oct 14 '11 at 2:49
@DKuntz2 Ah, yes, right, of course. Sorry, I was thinking about already being in the bridge, and where you could go along the bridge, and wasn't thinking about where you could get off/get on at either end. – Kromey Oct 14 '11 at 23:23

Stargate uses the analogy of phone calls quite often, so I'll try to give an answer in that direction.

Imagine that phone calls within the United States are very cheap, and that phone calls within Canada are similarly cheap (disclaimer: I have no idea if any of this is true, but you may have guessed as much already).

Phone calls between United States and Canada, however, are so prohibitive that you can't afford to make any unless you really need to.

So what do you do? You build a house on the border and have two phones in it, one connected to the United States phone Network, the other to the Canadian network. So now you can make phone calls between the United States and Canada for a more reasonable price and you don't need international (8th chevron) dialing.

(That said, I think it doesn't really make much sense that a Milky Way to Pegasus wormhole would be so prohibitive if you can cover the same distance with a series of shorter, cheap ones. I guess the telephone analogy hold there too, why do international calls need to be so expensive?)

The power requirements of dialing Earth from Atlantis required a ZPM, with the midway station, being you have a Milky way gate, and a Pegasus gate you can dial the MW one with the same amount of energy it would take to dial the Pegasus. Thus no ZPM required

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Argument from analogy sucks :( – Lightness Races in Orbit Nov 25 '14 at 13:56

The reason was that they couldnt link a Milky Way gate to the Pegasus Gate using the Macro that McKay did, was it was incompatable, meaning they had to stop at midway to redial to pegasus, or vise versa.

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There are 2 gates because the station is meant to connect Pegasus with Milky Way. There are actually approximately 17 gates on each side of the station at the edge of each galaxy. Midway in the center of the "corridor". Dr. Rodney McKay created a macro so that either side could dial a link through the 17 gates on either side to come out of the 18th, at midway station. Then they could do the same through the station to the other galaxy.

So, quick recap: Dial from Atlantis, link through 17 gates to station. Dial from midway, link though 17 gates to SGC. And vice versa.

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That doesn't answer anything. Nothing would prevent Midway station to have only one gate (as indicated in the OP). You could use the same gate to dial both sides, using an appropriate "macro". – bitmask Nov 8 '12 at 5:03

Maybe it is because the Pegasus gates and Milky Way gates have different constellations on them, depending on which galaxy they are going to. I know that may seem unlikely because they were able to directly dial Atlantis from Earth, but they have pointed out that some gates do not have the same point of origin symbols on them.

With such a vast network of gates in both galaxies, you would think that there would be different symbols for whatever galaxy you are in. In an episode of Atlantis they mention that they needed a control crystal to gate back to Earth directly. Just maybe that the control crystal reprograms Pegasus constellations as if they were Milky Way constellations, sort of re-mapping the gate for galaxy-to-galaxy travel.

The Avenger 2.0 episode, proved that they could re-map gate coordinates, so the theory here is that connecting to another galaxy would require to re-map the coordinates and that is why they use two gates at Midway Station because it could also take the extra power to remap gate coordinates as well as traveling from galaxy to another.

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This is one of several flaws with the execution of the Gate Bridge plot.

One is that the bridge, despite clearly being a forwarding mechanism initially, turned into a one-shot pass-through later on in the series: ref. "Adrift" in which Apollo dials Midway from within Pegasus which, if it were feasible, would render the entire purpose of the gate bridge more or less moot; the show began making a ton of seeming inconsistencies from this episode forward, as part of its "new direction".

Having the two gates served a vital dramatic purpose in emphasising the "midpoint" nature of the station, but ultimately it makes no sense whatsoever (Pegasus gates and Milky Way gates can dial each other without any problem at all) and required McKay et al to actually write explicit work-arounds for the problem it caused: which gate do you end up at, when both work perfectly well? In fact, even to "come up with a workaround" stretches credibility more than a little given the nature of wormholes snapping to the first charged gate they see.


  • Out-of-universe answer? The writers playing fast and loose with logic;
  • In-universe answer? The SGC's best and brightest playing fast and loose with logic.

Hence "no need for an iris or shield" — it would in fact be dangerous to add one, since you'd never be able to get synchronous confirmation that your IDC had been accepted before stepping through that first gate. Presumably this is why, once the security weaknesses of the forwarding macro were discovered, Midway was never rebuilt and the bridge gates were cannibalised for other use (such as Atlantis's new gate in "The Lost Tribe"). A massive waste of time and expense overall, if you ask me, though it felt like a very cool story.

If you could directly dial Midway then, at worst, you'd have to send your travellers from Atlantis to a planet at the edge of Pegasus so that they could "reach" Midway; this still seems a heck of a lot more convenient than placing umpteen Stargates across a galactic void, and then you could have an iris/shield and prevent all that nasty invasion business. The only alternative is that "dialling the bridge" automatically opened up all the gates en route so you could radio Midway, but this is total nonsense unless you have two gates at every single point along the route. The gates receive you, store you, dial the next gate then send you on. No radio transmission to/from Midway, at least not a real-time conversation, can possibly work in this scenario.

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Maybe a bit late to the party, but everyone traveling through midway has to remain there for 24 hours (as seen in the episode "midway"). This is to avoid pegasus system diseases to get to the milky way system. I can imagine that the entire reason for midway is this 24 hour pause.

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The Pegasus macro only works with Pegasus style gates and the Milky Way macro only works with Milky Way style gates. So one gate of each style was required, one for the Pegasus macro and one for the Milky Way macro.

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Some of the information contained in this post requires additional references. Please edit to add citations to reliable sources that support the assertions made here. Unsourced material may be disputed or deleted.

Very late, like years late, but I gotta answer this. It'll be quite long, so skip to conclusion at last paragraph if you are familiar with every episodes from SG-1 and SG:A, mainly ones cross-referencing each other.

That whole thing is because of how the macro works.

Pegasus gate always supersedes Milky way gates. This is a fact stated by Dr.McKay. We star here.

When there is two gates near each other, whatever you do, in normal gate operation, Pegasus gate activates first when you dial in from whatever location. That happens when Wraith attacked Earth at .

Midway station is at the farthest distant possible from each galaxy. you could gate midway from each galaxy without ZPM, if you are at the outer plant of the galaxy. That is verified when they used Daedalus as relay point to send message to each other to warn about Trust, also when Teal'c relayed message to Atlantis and to SG-1 when they tried to open gate to Milky way supergate from Pegasus. They only use the Mckay-Carter macro because they want to gate from Atlantis/Earth gates. Only, it is confirmed that Atlantis can gate Midway without any problem, possibly because Pegasus gate has better power consumption rate or so. Still, Earth gate cannot do that.

The macro works like this. When they open the gate to midway using macro, they actually open the gate to next gate of the series, then stores it in buffer, open next gate, sends, and do on.

However, like I said, Pegasus gates always supersedes Milky way gates.

So, if you think about this, There is a big danger using Pegasus gate and Milky way gate in mix, as we know how dangerous to play with buffer. There was one time when Teal'c was stored in buffer and gate shut down before he could be re-materialized on Earth-side. They mentioned that buffer could be erased if they open any warmhole while anything is stored.

So, think of it this way. Imagine there is no Midway station. You opened a gate to Atlantis form Earth using macro. That actually means you opened a gate to next gate in series. Gate sends it to next gate, next, next, and so on, and voila, you are in Atlantis.

Now, it's same situation. No Midway. Earth is sending people to Atlantis using macro. Now, buffer is sent to next gate in series, and so on. However, this time, Atlantis gates to Earth at exactly same time as Earth. So, each traveler's buffer meets where Pegasus-Milky way gate meets. there's no Midway, so they will be farthest distance. Now, two gates are storing buffer, and try to gate each other. As we know, Pegasus gate supersedes Milky way gate, and opens warmhole first, ignoring dial from Milky way gate. Then, buffer stored in that gate is erased and accept one from Pegasus. So, traveler from Earth is "erased".

It is simple as this. you cannot know when Milky way or Pegasus will dial each other. Because macro actually opens gate to next gate in series, they don't know if gate at the other end of macro is opened or opening. Pegasus gates "always supersedes" Milky way. So, if when they dial each other at the same time, buffer meets at the middle, Pegasus gate supersedes Milky way one, opens warhole and delete buffer from Milky way and stores one from Pegasus, deleting traveler from Earth while.

So, Midway station is to let travelers from Earth to safely stand while Pegasus travelers come in from Atlantis. Dr.Mckay had to tweak the gate system so Milky way macro actually open warmhole to Milky way gate, which is the whole point of Midway station. As long as Milky way gate only gates to Milky way gate, making Pegasus gate invalid, having two gate at the same point in space has no problem. Pegasus gate will supersede, which means Pegasus macro will gate to Pegasus gate, while Milky way macro invalids Pegasus gate and open warhole to Milky way gate.

Yep. That's the whole point to have Midway station. Because of the Macro, and how the gate system works. It's actually a workaround to the problem. But then, it found it's usage as 24h quarantine.

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(ok also really late into this convo!)

I like the analogy above of the "phone calls". ( the USA if I call within my state its a local call. but say im on the US/Canada border and the house behind mine is in Canada, it will still be charged as "international" phone call if I called it, eventhough its physically close to my house than say a house on the other side of my state).

Disclaimer: Im not that well versed in stargate "backstory" or facts... so maybe this will conflict with something said somewhere...

My logic is this: The gates require power to lock chevrons. I'm guessing the power needed is exponential so to lock one chevron requires 2 "units of power" [UOP], two chevrons require 2x2=4UOP, three require 2x2x2=8UOP, four require 2x2x2x2=16UOP etc...

So "normal" 7 chevrons requires 128 UOP To pegasus 8 chevrons = 256 UOP To destiny 9 chevrons = 512 UOP

A stargate on its own has enough power for a 128 UOP, but require ZPM for 256. So by keeping all the gates with "7 chevron" addresses no extra power is needed. If all the gates were connected directly from earth to pegasus then every gate would need an 8 chevron address, which would mean a ZPM for each gate.

So even with this logic, at the midway, if the "earth side" gate was to dial the "pegasus side gate", it would still need a ZPM as that would require an 8 chevron address as the pegasus gate is still in "another" galaxy.

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Well, we know that the two systems aren't inter-operable without a "hack" to get the gates to work together. There's no specific mention of power requirement. – Richard Jan 17 at 14:21

the Pegasus style gate superseeds the milky way gate because they are newer in design.

but the stargate takes the cordinates from its point in space.

sow milky way or pegasus style gate it does not matter.

it would be the same point in space.

so you could dailin from both sides to just one gate

conclusion one stargate is posible.

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Can you please add some punctuation? It's hard to read your answer otherwise. – Andres F. Dec 10 '13 at 20:46
It's really unclear what you're saying here. Can you improve on it? – AncientSwordRage Dec 11 '13 at 23:48

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