Greater Ark

The Greater Ark is an enigmatic Forerunner installation from which all the Halo installations across the galaxy can be activated simultaneously. In addition, it functions as a safe haven from the Halo network's strategic pulse, as well as a facility to construct and repair any of the original Halo Array. The Greater Ark is about 28 light years from the galactic center (For range comparison Earth is 25,000 light years from the galactic center). Unlike Installation 00 (the Lesser Ark), this Ark was not a secret and had a widely known location.

History
The Greater ark was part of the Master Builders plan for battling the Flood, this plan consisted of the twelve original Halo rings, and a smaller Ark, Installation 00. Located about 260,00 light-years from the galactic center, the Greater Ark is located outside the galaxy and is thus safe from the Halo effect (as it is referred by it's location to Installation 00) that kills all organic sentient lifeforms; the main Forerunner behind it's use was the Faber, The Master Builder. The commission of this installation is to remotely activate the 12 original Halo rings then in existence, from outside the blast radius of the array. In addition, This instilation can also function as an automated factory to construct replacement Halo installations (only the original 30,000km ones), thereby insuring that the Halo array is always ready to fire, should the array be needed.

This instalation was the Librarians original haven for her species, but they had to be moved when more Forerunners moved to this location, due to flood expansion.

One of the last battles in the Forerunner-Flood war took place in space around this installation. In this battle, the flood used captured forerunner ships, and star roads to engolf the Ark, and soon after destroy it. The only servivors of this battle are the Ur-Didact, the isoDidact, the Librarian, a small forerunner fleet (this fleet may not have come from this battle though) and many lifeworkers. This battle also caused the Didact to distribute and fire the halo array from the Installation 00.

Layout and Fuction
The Greater Ark is believed to be identical to Installation 00, only smaller and less complex. Like the lesser Ark, the Greater Ark has the ability to remake or fix Halos, but can only do this for the larger, weaker original Halos.