Damascus Testing Facility
The Damascus Materials Testing Facility was a UNSC base located in the Chi Ceti system on planet Chi Ceti IV in the Outer Colonies. This top-secret base is where the Spartan-II supersoldiers were relocated for their final stage of training and the inclusion of their MJOLNIR Mark IV battle armor in 2525. Though it was only manned by three technicians, it had a curious feature, which was that a dozen AIs could operate and utilize the facility in close proximity to one another, which is typically impossible under normal circumstances for technical reasons. Dr. Catherine Halsey also worked here for a while to refine the MJOLNIR armor series. The MJOLNIR/EOD was also created and constructed here. There were also obstacle courses for the Spartans to become accustomed with their new armor.
Right after the Spartans received their armor, the facility was attacked by a nearby Covenant ship, the Unrelenting. All personnel were evacuated and the AIs were deactivated by Halsey when she removed them in the form of data cubes. Spartans John-117, Kelly-087, and Sam-034 boarded the Unrelenting and destroyed the ship by detonating missiles requisitioned from their Pelican dropship on one of the plasma cannons.
- The facility was likely named after Damascus, the capital city of Syria. The facility also may have been named after Damascus steel, a type of steel used in sword-making during the Middle Ages. This steel was renowned for its strength and sturdiness. The exact process for forging it is believed to have been lost.
- In the Halo: Fall of Reach comic adaptation, the Damascus Facility is depicted as an orbital station, a departure from the novel and Dr. Halsey's journal which depict it as a base located deep underground. The facility's depiction in the comic book also bears a striking resemblance to the central section of the space station Deep Space 9 from the Star Trek series of the same name.
 List of appearances
- Halo: The Fall of Reach (First appearance)
- Halo: Fall of Reach
- Halo 3 (Mentioned only)
- Halo: Reach (Mentioned only)