From Halopedia, the Halo wiki
RECON-class Mjolnir, also designated as the MJOLNIR Powered Assault Armor/R variant, is a stealth-oriented variant of the MJOLNIR Powered Assault Armor that was originally commissioned by the Office of Naval Intelligence and developed by the Materials Group, with the GEN2 version being manufactured by the Imbrium Machine Complex.
The visor used was the B5D-R/Optics Suite.
A prototype was created prior to the Fall of Reach concurrently with the Mark VI Prototype. Like the Mark VI Prototype, the armor underwent field tests to improve the final model. Before being finalized Recon was already shown to reduce armor silhouettes without decreasing survivability.
The Recon armor was developed parallel to the Scout armor in the Office of Naval Intelligence's Beta-5 Division Ordnance Testing Facility in Swanbourne, Perth, Western Australia. The armor was designed to provide the wearer with stealth capabilities and with little or no loss of endurance, specifically by reducing its infrared signature, reflective surfaces, and Cherenkov radiation emission.
The helmets visor system was changed to a APL-72 visor system. The chest has an infrared signature modulator, and a X900-Boulder emission shroud (IMC-spec). The reactor pack has a Bravado-120-B4 fitted stabilizer for masking reactor footprint.
It offers improved movement stabilizers and adjustable shield distribution channels for versatility during deep-field reconnaissance.
The GEN2 Recon helmet also contains a highly classified Auspex battlenet uplink featuring state-of-the-art ONI counter-cyberintrusion and firewall routines. The armor itself is fitted with emissions baffling and plasma electronic support activity sensors for observation missions behind enemy lines.
The greaves are an off-market system that feature exposed shield conduits.
As a result of the UNSC Ordnance Commission in 2553, Imbrium Machine Complex took over production of the Recon variant after the Human-Covenant War, where they refined and improved the existing architecture. The GEN2 variant was tested at Anakara Resiliency Chamber with it being quickly done, as by January 2553 a copy of the armor was on board the UNSC Infinity.
Most operators indicate the armor has a notably higher resiliency and much leaner reaction-time margin.
In the post-war era, custom-built upgraded and up-armored RECON [GEN1] helmets remain in service with individual ONI operatives. Such helmets, equipped with cutting-edge stealth and cyberwarfare suites, were used by ONI teams responsible for information sanitation operations on Created-occupied Earth.
The Recon armor was first unveiled on Bungie Day 2007, in a piece of artwork created by Isaac Hannaford. This followed the unveiling of the new armor permutations system, though only the Mark VI, EVA and CQB sets were detailed. The Recon armor remained a mystery until launch, when it was revealed as an exclusive set awarded by Bungie to community members for specific accomplishments that impressed the Bungie staff. The launch of Halo 3: ODST in late 2009 saw the Road to Recon challenge unveiled; players who unlocked all of the Vidmaster Challenges across Halo 3 and ODST were prompted to visit Bungie.net, whereupon they would be able to click an "Unlock My Recon" button in their service record.
The Road to Recon was discontinued in 2012, with the transition of all Bungie.net stat-tracking and online services to Halo Waypoint; as such the Recon armor is now unattainable in an Xbox 360 copy of Halo 3 without the use of modding. To compensate, 343 Industries unlocked the armor for all Xbox LIVE accounts in two waves around this time, though any accounts made since then will be unable to benefit from this.
In the Halo: The Master Chief Collection edition of Halo 3, the Recon armor (like all Halo 3 permutations) is unlocked by default.
The Recon set returns in Halo: Reach, though largely unrelated to its Halo 3 predecessor in visuals. The Recon helmet was the subject of the game's pre-order bonus, with such purchases allowing players to use the Recon helmet with the UA/HUL attachment on day one - this specific helmet variant cannot be unlocked any other way. The other Recon helmet, chest and shoulder armor types are unlockable in the game's purchase system via the use of cR. In Halo: The Master Chief Collection, the Recon set (including pre-order bonus) is attainable in the Season 1: Noble progression system, with an additional robot arm variant of the Tactical/Recon chest introduced in Season 5: Anvil.
Recon was one of the armor permutations to return, albeit redesigned for GEN2, in Halo 4. The helmet bears similarities to previous iterations, though the chest and shoulders have little design lineage. In The Master Chief Collection, the Recon set was available by default, though the introduction of armor customisation in Season 4: Reclaimer saw the return of the SURGE skin, previously unuseable in Halo 4.
Halo 5: Guardians
The Halo 4 design of Recon returns in Halo 5: Guardians. The helmet and body armour are unlockable through the Requisition system. The body armor includes the Recon chest and shoulders, the Contoured forearms and an unknown leg model. The Memories of Reach update saw the addition of the Recon (GEN1) helmet, based on the design seen in Halo: Reach. The GEN2 Recon set has three skins; RSO, BDA and ITG.
Halo 4 skins
Halo 5: Guardians skins
Halo 5: Guardians REQ cards
List of appearances