Installation 01

Installation 01, is one of the Seven Halo Rings. Very little is known about it but it appears to have a moon-like landscape. Because of this, one could predict a lack of atmosphere on the installation.

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

 * The surface resembles that of Mars (in fact, the surface is a picture of Mars' surface), though it has not yet been confirmed what it's exact composition is. More examinations would be needed to confirm the surface's components.
 * No water surfaces can be seen or have not yet been detected.
 * The numbering of the rings concerning the IWHBYD ring sequence is the opposite to the rings' actual installation numbers and should not be confused.
 * Due to a possible lack of water, there might not be active lifeforms except the Flood on the ring.
 * Due to the amount of craters covering the ring, it is safe to predict this ring has no atmosphere, it was most likely left this way due to time constraints on the Forerunners part.