I tried to find out a way how the SGC and Atlantis could rescue the crew of Destiny with the known technology from all 3 shows :
Dr. Carter and Dr. McKay knows that the Destiny has gone through the Pegasus galaxy, so they create a new version of Avengers (v3.0) program (from SG-1 7x07 Avenger 2.0) to infect the Pegasus gate system. They wanted to locate all the potential gates in the system, because they hoped that maybe not all of the Universe type of gates were collected when the Ancients arrived to create their newest gate system (the P-gates). And they were right, so they can finally study the actual old U-gate on an abadonned planet by a group of scientists.
McKay, Carter and Zelenka believe that they could track the path of Destiny through the numerous galaxies if they could infect all the U-gates with the Avenger virus even without the DHDs, so virtually the U-gates would dial each other, so they could always map all the short ranged U-gates in every galaxy really quickly without a KINO. They can not count on the help or the datebase of the Destiny as they are in their sleep chambers for years now. McKay still believes that the small ranged U-gates are capable of transfering materials in the memory of the gate without opening an active wormhole as his plan worked with the intergalactic gate bridge before. His plan is that instead of flying on the board of Odyssey after Destiny, they will use the established U-gate systems.
So Vala and Daniel goes to the Ori galaxy to speak with Tommin to create more supergates. Unfortunately since the Ori and Adria have died they are not able to build more ZPMs, Ori ships or supergates. In spite of the efforts the locals still believe the Tauri and the Milky way is a threat to them so Daniel starts a successfull negotiation to take apart at least the current working supergate on their end and send back the gate pieces to the Milky way through their on small stargates, so the connection between the galaxies would be broken forever. The parts of the supergate in Milky way are also gathered and sent to the Pegasus galaxy through the newly rebuilt Carter-McKay intergalactic gate bridge 2.0.
The Odyssey flies the edge of the Pegasus galaxy where they build the first supergate, they dial in the next galaxy with a careful calculation to reach any potential U-gates there, then send through the second supergate pieces. They manage to make the jump wormhole to the supergate, so the Odyssey can fly through. Before the wormhole disconnects they make the wormhole jump back to the normal P-gate at the starting site and they send the supergate pieces after them.
So that is where the new adventure starts. The Odyssey will alway map the local gate network with the Avengers 3.0, so they can quickly send sets of supergates in the gate's memory at the edge of the new galaxy. Then they build a new supergate again, dial in to the next galaxy with U-gate to U-gate send the pieces of the second supergaste pieces through then wait and collect the first supergate pieces again and so on.
This way the Odyssey could cross a few hundreds galaxies in a few years time. Pick up the Destiny and go back. But that is an other story for later...
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I know this idea is a bit forced, but I always imagined the rescue of Destiny with the help of SG-1 and Atlantis while they are using their own logic and the established gate system protocols.
The only things which are not so clear that there were 2 different type of supergates in SG-1:
1. first in 9x06 Beachhead which pieces were fit through the startgate
2. second in 9x20 Camelot which pieces were much larger
so obviously I was talking about the first one in my idea. There must be a limitation of how many can be build by the Ori galaxy, so I believe it would be wise to accept that they won't be able to produce more without the guidance of the Ori masters.
It is also not clear how these supergates were working. Sometimes they said it need a black hole on both end, sometimes just one end, because it is so energy consuming to dial a galaxy from an other galaxy. We know that wormholes can jump like in Pegasus project. But it would be nice to introduce a technology where you could make the wormhole jumps at the starting and/or at the arriving site. I am just a fan, so I am sure the official writers can find a believable solution (like from Asgard database).