The Knossos Device is a massive Subspace Portal created by the extinct civilization known as The Ancients. It generates a stable Subspace Node that allows ships to reach a distant point in space via Subspace, though its actual purpose is unknown.
The Knossos Portal is comprised of an array of eight cruiser/corvette-sized modules arranged in a large ring formation. The interlocking movement of the portal's componets create a localized Subspace vortex linked to another point in space. Since it is possible that the Portal's Jump Node was originally a Node that had collapsed or had been too unstable to use, it is believed that the Knossos may be used to stabilize Jump Nodes that are otherwise unusable.
Three Knossos Portals were discovered by the GTVA.
The first Subspace Portal was first discovered by the NTF leader Admiral Aken Bosch in the remote Gamma Draconis System near the end of the NTF Rebellion. He had learnt of the device from stolen Ancient artifacts in Deneb, and had sent the NTC Trinity to activate the portal. The portal led to a vast nebula in an unknown region of space, presumably a system the Ancients once inhabited prior to their destruction. A massive Shivan fleet was found within the Nebula system, which later began to move into Gamma Draconis via the Knossos Portal. After a Shivan attack at the Gamma Draconis Node in Capella, the GTVA mobilized and launched a counterattack against the Shivan forces and discovered the Portal and the Nebula. This was the start of a prolonged campaign to explore the Nebula System prevent the Shivans from invading again.
Some time into the Nebula Campaign, the Alliance learned of a massive Shivan warship, the SJ Sathanas, heading on a direct course for Terran-Vasudan space. After Allied forces in the Nebula failed to stop the Juggernaut's progress, they retreated to Gamma Draconis and deployed experimental Meson Bombs to demolish the Knossos Portal and, hopefully, cut off the Shivans' only entry point to Allied space. They succeeded in destroying the device, but unfortunately, the Nebula Jump Node remained stable, and the Sathanas soon arrived and continued to push on through to Capella.
After defeating the Sathanas in the Capella System, the Alliance resumed its Nebula operations, starting with the search for the rebel leader, Admiral Bosch, who had fled into the Nebula at the end of the NTF Rebellion. A Shivan Transport that was believed to be carrying Bosch and his colleagues was tracked to a second Knossos Portal deep in the Nebula. Before the GTVA could secure the device, a second Sathanas Juggernaut emerged from the portal, which was soon followed by a massive Juggernaut fleet. This prompted a full retreat from the Nebula and Gamma Draconis. However, a small task force from Allied Special Ops. Command, piloting captured Shivan Fighters, was sent to investigate what lay on the other side of the portal. They found that it led to a binary system that was home to an extensive Shivan base, including a rapidly growing fleet of Shivan Juggernauts.
During a recon flight by SOC in the binary system beyond Knossos 2, a third Knossos Portal was found at the Shivan fleet base. A massive fleet of Sathanas Juggernauts had been seen emerging from the portal and amassing in the system. Nothing is known about what lies beyond the third portal, other than that it leads deeper into Shivan space.