"And before long we could see the day when our reachable systems would have been exploited, and then there would be nowhere else to go. And we discovered subspace. It gave us our galaxy and it gave us the universe." -The Ancients
Subspace is a form of warp-based travel commonly used by the Terrans, Vasudans and Shivans.
There are two methods of Subspace travel. The first is In-System jumps, which is often used by smaller ships, such as fighters. In order to facilitate such short-range jumps, there must be a gravity well present, such as a star's.
The second method is Intersystem Jumps, which utilize special Jump Drives to warp between star systems in conjunction with localized "Jump Nodes". For many years, only larger vessels like freighters and capital ships could use Jump Drives, but a miniaturized version developed for fighters was introduced in the waning days of the Great War.
Jump Nodes are localized Subspace warp fields used for Intersystem Subspace Jumps. Jump Nodes are very tricky and unpredictable, as many are prone to collapse suddenly and without warning. The Jump Nodes sanctioned by the GTVA are expected to remain stable for many years.
Jump Nodes can be collapsed by setting off a large explosion while in transit through Subspace, as shown by the destruction of the Shivan Destroyer Lucifer. The detonation of the warship's reactors caused a Subspace cataclysm that had collapsed the Sol Jump Node in Delta Serpentis, cutting off all contact with Earth. The GTVA has been able to replicate such an event by utilizing Meson Bombs.
Shivans and SubspaceEdit
The Shivans are known to be highly sensitive to Subspace disturbances, and they possess advanced Subspace technologies themselves. For example, they have been able to circumvent blockaded Jump Nodes by making intersystem jumps using uncharted Jump Nodes and Nodes too unstable for Terran and Vasudan craft. In addition, they possess some form of Subspace-based weaponry, as evidenced by the destruction of Capella's sun at the hands of the Sathanas Fleet. The Juggernauts had generated a Subspace anomaly that had caused Capella to go supernova. No details are given on how or why they had caused the destruction of Capella.