Installation 01

Installation 01 is one of the Seven Halo Rings. Based on the information gathered from Master Chief's reconnaissance in the Citadel, the landscape on this ring is made up of an endless desert with a limited atmosphere.

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 01 was fully prepared to fire on demand.

A more comprehensive readout was later observed on the Ark during the Battle of the Ark by the Arbiter, Master Chief and the Prophet of Truth. It once again displayed that Installation 01 was in standby mode, being prepared to receive the signal to fire. However, the Master Chief deactivated the installation before it could be fired.

Trivia

 * No water surfaces can be seen or have not yet been discovered.
 * It appears to have a Martian surface, which could mean that there is water under the ground.
 * The numbering of the rings concerning the IWHBYD ring sequence is the opposite to the rings' actual installation numbers and should not be confused.
 * It is the farthest Installation from the Ark.