Star road

Star roads, also known as unbending filaments, were a form of Precursor technology.

Overview and history
One of the more common types of artifacts left behind by the Precursors, star roads were seemingly inert, several-kilometers-thick, virtually unbreakable cables on an immense scale that lay across the galaxy for millions of years. On some worlds, star roads formed orbital and suborbital structures like orbital arches. On a larger scale, they were used to connect and link planets and even entire star systems to one another. Like other Precursor technology, star roads were not made of ordinary matter, instead being composed of exotic neural physics construction. Charum Hakkor and its system was once home to many star roads, which were used by prehistoric humans to link their orbital defenses surrounding the planet. In their dormant state, star roads or the larger structures they comprised automatically adjusted to changes in planetary and stellar orbits, even occasionally removing portions of themselves. A particularly complex web of star roads in a system in Path Kethona had not survived the eons completely intact, having crumbled in several sections.

Weaponized star roads
During the last decade of the Forerunner-Flood war, it was revealed that the star roads were not completely inert. Having amassed a sufficient level of sheer intellect to elevate them to a state of transsentience, the Flood's newly-developed Key Mind forms began to take control of star roads, along with other once-inactive neural physics constructs, and wield them as weapons. The star roads, in their weaponized form, were incredibly powerful, being capable of either physically tearing apart Forerunner fleets or interfering with Forerunner slipspace travel as well as generating suppression fields to disable Forerunner weapons, ancillas and shields. The Flood moved star roads across interstellar distances by using the Precursors' neural physics-based method of superluminal travel, which they also utilized to transport their converted vessels. The Flood-controlled star roads warped reality around them which not only enabled organic beings to feel when they were nearby, but also mutated space-time and converted slipspace to be unsuitable for Forerunner transit. In many engagements near the end of the Forerunner-Flood war, star roads were used to trap Forerunner forces that were soon overwhelmed by the Flood. One example of this is the Battle of Kan Pakko, in which the Forerunners were defeated by the Flood due to the star roads' influence. The star roads were also used by Mendicant Bias to trap most of the surviving Forerunners before the Battle of the greater Ark.

The Flood configured star roads to various formations when using them as weapons. One common star road configuration was shaped like two parallel double-arcs, over 50,000 kilometers in diameter, and contained thousands of interwoven star roads. In the center of each double-bow was a point of inky darkness surrounded by a glowing ring. These double-bow configurations were capable of tearing planets apart with their sheer tidal forces and kinetic energy by wrapping around them; one such formation destroyed Uthera Midgeerrd. It was theorized by Maker-of-Moons that the Precursors moved stars the same way, by forcing changes on their orbits with star road formations.

Destruction
Since star roads were based upon the fundamental principle of neural physics, they were vulnerable to the effects of the Halo Array. The first evidence of this was when the Precursor structures on Charum Hakkor were destroyed by Installation 07's test-firing. To all available knowledge, the Forerunners succeeded in destroying all remaining star roads in the Milky Way when the Halo Array was fired. It was theorized that star roads and other Precursor constructs in slipspace transit may have been able to survive the pulse, although this was not known for certain; to inflict as much damage as possible, the Forerunners would time the firing to a point when the maximum number of star roads would occupy normal space.

List of appearances

 * Halo: Cryptum
 * Halo: Silentium