The Beta-5 Division was a UNSC Office of Naval Intelligence Section Three subcell.[1] It was extremely secret, known by very few UNSC, or even ONI personnel.


By December of 2553, Rear Admiral Serin Osman was the head of Beta-5.[2]

The Beta-5 Division continued operations through to at least the 2580s.[3]


It was charged with the SPARTAN-III Program and was also known for its extreme decryption facilities.[4]



The helmet used by Beta-5 security forces was a shared asset between branches of the UNSC military and was also been adopted as the MJOLNIR Military Police variant.[5]


Beta 5 Strike Teams often utilized the Bubble Shield.[6]


The Beta-5 Division Ordnance Testing Facility, a Beta-5 Division installation in the Swanbourne, Perth district of Western Australia, designed and tested S-variant[7] and R-variant[8] Mjolnir Powered Assault Armor,[5][9][10] as well as the Operator variant with Chalybs Defense Solutions.[11][11][note 1]






  1. According to the Armory in Halo: Reach, the Operator armor was developed at the Beta-5 Division Ordnance Testing Facility. According to Halo: The Essential Visual Guide, the armor was developed by Chalybs Defense Solutions and was tested at Chalybs' Testing Preserve. The article assumes that the two organizations jointly developed the armor.


  1. Halo: Ghosts of Onyx - Page ??
  2. Halo: Retribution - Chapter 2, Page 27 (Digital)
  3. Halo: Reach Legendary Edition Bonus Item: Box Contents Letter
  4. Halo: The Fall of Reach - Page 55
  5. 5.0 5.1 Halo: Reach - Description: Military Police
  6. Halo: Reach - Bonus Item: Instruction Manual
  7. Halo: The Essential Visual Guide - Page 165
  8. Halo: The Essential Visual Guide - Page 152
  9. Halo Waypoint: MJOLNIR Project 2
  10. Halo 3 - Descriptions: MJOLNIR Mark VI Scout and MJOLNIR Mark VI Recon
  11. 11.0 11.1 Halo: The Essential Visual Guide - Page 133