Installation 03

Installation 03 is one of the seven Halo Rings. Very little is known about it and it has yet to be directly observed.

In 2552, during the Battle of Installation 05, a signal was sent to this Halo from Installation 05, putting it on standby mode. A readout from Installation 05's Control Room showed that Installation 03 was fully prepared to fire on demand.

A more comprehensive readout was later observed in the Ark during the Battle of Installation 00 by the Arbiter, the Master Chief, and the High Prophet of Truth, once again displaying that Installation 03 was on standby mode, prepared to receive the signal to fire. However, the Master Chief deactivated the installation before it could be fired.