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Lieutenant Commander Michael Pomare, Office of Naval Intelligence, UNSCDF Navy
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MJOLNIR Powered Assault Armour
Production information

UNSC Navy / Office of Naval Intelligence / Naval Special Weapons Division


Mark I through VI


Combat exoskeleton



Technical specifications



User-operated strength/speed/reaction time enhancement, portable communications uplink, compatible with all UNSC weaponry and equipment, and most enemy technology.


Sangheili Combat Harness


United Nations Space Command


Powered armour is nothing new to military engineers, and the first designs entered service as early as the mid- to late-21st Century. Over the next five centuries, however, the concept has undergone some radical shifts in design philosophy, has been abandoned, readopted, and abandoned again, various declared impractical or revolutionary, and was finally adopted by the UNSC Navy as cursory experiments in combat exoskeletons. Though it was by no means the only project to investigate these concepts, the MJOLNIR Project of 2512 was the best known of these projects, and after being adopted by Doctor Catherine Elizabeth Halsey it would become the most recognisable and successful powered armour projects of all time. Numerous technologies initially developed for MJOLNIR would enter service in other military branches, and would field-test numerous experimental or dangerous technologies in combat conditions under SPARTAN-II or III personnel. With the disappearance of Doctor Halsey, the Project is currently under the auspices of Codename: VOLUND, also the head of Project: TEMERITY, supporting field-issue Mark V and VI armour systems and developing further improvements, additions, and replacements for future use.


Powered armour is not a new concept. Popularised by science fiction stories of the middle 20th century, the first prototypes of the concept were developed as early as 1965, and further developed well into the 21st century, but never perfected or deployed. Critical weaknesses of the prototypes' designs - excessive weight, energy dependence, hampered mobility - all contributed to its postponement as a piece of combat equipment, and for the time cheaper, more efficient and effective alternatives were readily available using off-the-shelf technology. With little incentive to replace their tried-and-tested equipment with experimental powered armour, deemed adopted the technology as viable. Powered armour would continue to be developed through the 23rd, 24th and 25th centuries, but were always deemed inferior to off-the-shelf counterparts.

That would change in 2490. With the development of new technologies and design philosophies for powered armour, the UNSC finally deemed that its time had indeed come. Various projects were initiated, developed, and abandoned for one reason or another. Project HALBERD was shut down due to Insurrectionist infiltration. Project MCDOUGAL would fail, lacking sufficiently small, compact power systems. Project SARISSA would deem the materials it had to work with too inferior for constuction, while Project UNDERDOG was deactivated because of budgetary concerns. Only three projects were left by 2512, and all showed promise - Project CYCLOPS, Project VAJRA, and Project MJOLNIR. Of these only MJOLNIR has reached any state of recognition, becoming the iconic image of the SPARTAN-II Program. The Cyclops Powered Armour Exoskeleton would be approved by the UNSC Marine Corps for limited service, seeing combat in limited runs, but was eventually relegated to the role of hangar loader and heavy lifter. Project VAJRA would be shut down in the wake of MJOLNIR, FLEETCOM deeming the cost of running two parallel powered armour projects alongside one another too much for their current budget, especially given the expense of MJOLNIR and the spectacular results it produced. The prototypes would eventually be relegated to the New Alexandria Museum of History, a relic of a time before humanity's threats came from other stars, though rumours of continued operation of some prototypes would continue to circulate.

Started in 2490, MJOLNIR was initially little different to past iterations of powered armour thinking. It used mechanical and hydraulic systems for mobility, controlled by a "wearer" buried within centimeters of thick Titanium-A battleplating, with external hardpoints for mounted weaponry. In every sense of the word, the original three iterations of MJOLNIR were true exoskeletons, fully encasing the occupant in a metal shell. But even in the early development phase, the project showed significant promise - increasing the wearer's speed, strength, and reaction time to above-normal levels. Restrictions posed problems for development - the original Mark I was deemed far too large and bulky for easy deployment, and suffered power supply problems that would plague its two predecessors. The Mark II would be downsized and streamlined, improving performance and cost, but its mobility was hampered by its requirement of a direct power uplink - the energy requirements of the suit were simply too much for the suit to carry itself. The Mark III would propose to solve this through an orbital power supply, broadcasting the energy wirelessly, but this was deemed inadequate, and potentially catastrophic - any interruption of the power supply would render the wearer trapped in a metal coffin, vulnerable to enemy fire. With no signs of improvement any time soon, FLEETCOM considered scrapping the entire project.

The arrival of Doctor Catherine Elizabeth Halsey to the program in 2511 would radically change the design philosophy of MJOLNIR, and would revolutionise the way military researchers saw powered armour. In the past, developers had built the suit armour human capabilities and requirements. Her approach was to invert that - she would literally develop the wearers, the SPARTAN-II personnel who would make the design iconic, around MJOLNIR's needs, with bioligical, genetic and cybernetic augmentations that would allow them to control the unstable but astonishingly powerful suit. Rather than rely on the clunky hydraulic systems of past iterations, Halsey would make use of the Piezoelectric effect, using polymerised lithium niobocene, a material originally developed to discharge static accululated from Shaw-Fujikawa Space on starships through physical distortion. Halsey was the first to realise that running a charge through the material would produce movement disproportionate to the effort of generating the charge, producing far more strength and speed for much less power. The material would be used extensively through the next iterations of the MJOLNIR series, the Mark IV, V and VI suits. In fact, besides a few small design carry-overs, the IV would be a radical overhaul of the concept, discarding almost all of the work done for the Mark I, II and III and starting from scratch. Although metamaterials are difficult to fabricate and usually fragile, MJOLNIR would generate a variety of classified materials for use on the armour system to dramatically improve ballistics protection and reduce the armours weight, and for protection against nuclear, biological and chemical threats, most of which remain classified, even after the conclusion of the Human-Covenant War. Many of these would be incorporated into standard issue among other military branches, with improved ceramic-titanium composites included in ODST standard issue combat armour. By the end of testing, in 2525, the Mark IV would still weigh 500 kilograms and the performance of the suit was far too high for use by unaugmented personnel, and even augmented personnel such as the original ORION members.


The end of MJOLNIR's testing coincided with perhaps the most important event in human history: first contact with an aggressive and advanced extraterrestrial faction at Harvest, calling itself the Covenant. In the face of the catastrophic loss of Harvest, the encounter with a genocidal alien society, and the growing threat of the Insurrection, FLEETCOM eagerly jumped at the chance to approve both the SPARTAN-II Program and Project MJOLNIR for combat deployment, and both programs were accelerated - the Spartans were fully augmented and completed their training, while the MJOLNIR Mark IV entered production at the Damascus Testing Facility at Chi Ceti IV. Halsey and the Spartans rendezvoused with the frigate UNSC Commonwealth over Reach, and entered Shaw-Fujikawa Space en route to the Chi Ceti system.

Arriving in the region, the Commonwealth would encounter a Covenant warship, likely of corvette or frigate classification, engaging the enemy at extreme long range with Archer missile barrages and multiple MAC rounds, sustaining extensive damage and managing to inflict minor damage on the enemy, but succeeding in driving it off long enough for the Spartans and Halsey to reach the facility. Conducting preliminary tests, the armour was approved for its final status check, and saw immediate action. En-route to the frigate, the Spartans used their Pelican dropship to stage an assault on the Covenant ship, blowinjg a hole in the ship's shields long enough for a small team of Spartans, consisting of John-117, Kelly-087, and Sam-034 to insert into the ship, planting a HAVOC nuclear warhead within it. Faced with a breach of suit integrity, Sam-034 was forced to stay behind, detonating the bomb manually - the first Spartan casualty of the war, and the first MJOLNIR suit lost in combat.

Over the next twenty five years, the MJOLNIR Mark IV would see further development and refinement, with field upgrades and updates applied sporadically. As revolutionary as MJOLNIR was, there were still factors that it had failed to compensate for. Directed energy weapons were never a part of the design brief, and makeshift measures were found to diffract/reflect Covenant DEW weapons to a limited degree. Specialised variants were developed, such as the Security, Extra-Vehicular Activity, Close-Quarters Combat, and Grenadier variants, each adapted from the basic issue suit for radically different types of deployment. More surprisingly, the suit's weapon and ammunition tracking systems were something the designers had never anticipated would need updating, and had been installed from UNSC Marine Corps issue programming. A Marine carrying a pistol in each hand may seem a novel idea, and certainly looks impressive, but the reality is that one hand is insufficient to aim and control the recoil - at least for an un-augmented individual. Spartans had no such problems, and combat personnel attempting to "dual wield" would find their suits' tracking systems crippled by resulting bugs, fixed with a makeshift patch for a problem that would not be fixed fully until the Mark V variant. Worse still was the programs inability to recognise Covenant materiel for use, a requirement for the special warfare operations Spartans would be deployed on. As the UNSC made technological advances, these found their way into testbed prototypes - experimental materials and equipment, prototype fusion reactor upgrades, and even limited energy shielding on the MJOLNIR Mark IV/V-II A, D and E variants, as well as the Mark IV [g] Grenadier variant, using a misture of electromagnetic and solid light energy shields. By 2551, most of the armour's systems had been rendered out of date, and Halsey was ready to begin the next phase of MJOLNIR - the Mark V.

Much has been made of the design differences, or lack of them, between the Mark IV and Mark V models. Both suits share the same helmet as standard issue, a fact that has caused some confusion among intelligence circles, and have a similar external layout. Indeed, aesthetically the Mark V is almost identical to its predecessor, with some exceptions. The largest differences were purely technical, but they were dramatic: the various updated components and systems; the inclusion of a vastly improved reactor system, both smaller and more efficient; as well as the incorporation electromagnetic energy shielding systems, reverse-engineered by Halsey alongside Project TEMERITY. Solid light barriers had initially been explored for future iterations, and tested on Mark IV variants, but were deemed incompatible with mobile special warfare needs. The most significant change, however, was the inclusion of a layer of data memory crystal within the Mark V, allowing the wearer to carry a Fifth Generation "Smart" artificial intelligence. Such systems had been planned during the early years of the Spartans' deployment, but abandoned due to cost and technical concerns. By 2551, CENTCOM was desperate enough to put Operation: RED FLAG into effect, and for that they required advanced MJOLNIR-equipped Spartan operators with Smart AI capability, accelerating the Mark V into production. Introduced in 2551, the Mark V would improve the Spartans capabilities drastically, especially the inclusion of energy shielding, and would change the way Spartans would wage war against the Covenant.

Already, Halsey was working on the Mark Vs replacement, the Mark VI. While the Mark V would continue to serve throughout that year, and the next, the Songnam Testing Facility would continue to work on improving and refining the design further, using information derived from combat personnel. Various Spartan personnel serving in Operation: HOT GATES at Minorca would contribute to Songnam's understanding of MJOLNIR systems, while work continued on reverse-engineering and improving Covenant shield and energy systems. During its short but stellar service, the Mark V would see deployment in several combat theatres, including Minorca, Reach, Earth, Onyx and Ares.

Introduced in October, 2552, the Mark VI was a major aesthetic improvement - more streamlined, and with improved mobility. Technically however, the Mark VI is largely similar to the Mark V, though it features minor improvements to the energy shield systems, an improved plasma energy reactor, and the inclusion of biofoam injection ports and updates to the weapon/equipment tracking systems and helmet-mounted display. The newer nature of the Mark Vi means that fewer unique variants were created. So far, the standard Mark VI/IC "Integrated Communications", Mark VI/V "EVA", Mark VI/S "Scout" and Mark VI/A "Rogue" are all unique to the suit, though it adapts a few previous variants - the Mark VI/C "CQB", Mark VI/R "Recon", Mark VI/EOD "Explosive Ordnance Disposal", and a number of others, not to mention the former standard Mark IV and Mark V helmet, were all updated and integrated into the more advanced MJOLNIR suit, modified for compatibility with the new power supply and shield systems, and updated with improvemments introduced after their own introduction.

Future Development

The Mark V was intended to be replaced after 2552 by the Mark VI as the standard issue MJOLNIR equipment for Spartan forces, though post-war shortages meant that the majority of Spartan forces were forced to continue to operate the Mark V variant, or older, updated Mark IV suits, supported by the VAJRA-II subsection of MJOLNIR. Doctor Halsey talked about a proposed Mark VII MJOLNIR variant, supposed to be the pinnacle of her project, including vastly superior energy shield manipulation, allowing unaided orbital descent, and featuring vastly improved systems throughout. With the disappearance of Doctor Halsey, the Mark VII was put on hold until her whereabouts could be ascertained definitely. Small progress continues, with Songnam researchers continuing to work on improvements for serving Mark IV/V/VI suits, but the Mark VII was intended as a radical redesign, and for that Halsey's expertise is desperately needed.


First Generation




Second Generation



  • MJOLNIR Mark V[B] - Privately manufactured variant issued exclusively to SPECWARCOM Group Three.
  • MJOLNIR Mark V[M] - also known as Security. Privately manufactured variant with radio antenna.
  • MJOLNIR Mark V/CQC - Close-Quarters Combat. Precursor of the MJOLNIR/C variant.
  • MJOLNIR Mark V/C - A more advanced Close-Quarters Combat variant.
  • MJONIR Mark V/HAZOP - A variant for missions considered too hazardous for standard equipment.
  • MJOLNIR Mark V/HP/HALO - Additional armor plating and hard points for missions involving High-Altitude Low Opening jumps.
  • MJOLNIR Mark V/SCOUT - A variant with limited stealth capabilities.
  • MJOLNIR Mark V/FJ/PARA - A lightweight variant for airborne units.
  • MJOLNIR Mark V/RECON - A stealth variant specialized for reconnaissance missions.
  • MJOLNIR Mark V/OPERATOR - A variant used by Beta-5's Asymmetrical Action Group.


  • MJOLNIR Powered Assault Armor/Black -
  • MJOLNIR Mark VI MJOLNIR Powered Assault Armor/C -
  • MJOLNIR Mark VI MJOLNIR Powered Assault Armor/V -
  • MJOLNIR Mark VI MJOLNIR Powered Assault Armor/EOD variant -
  • MJOLNIR Mark VI MJOLNIR Powered Assault Armor/S variant -
  • MJOLNIR Mark VI MJOLNIR Powered Assault Armor/R variant -
  • MJOLNIR Mark VI(A) MJOLNIR Powered Assault Armor -


As the UNSC's most advanced combat armour systems development project, MJOLNIR was an integral part of the modernisation process of the UNSCDF as it upgraded itself to cope with the devastating onslaught of the Covenant armada. Pioneering the integration of neural interface technology and the use of advanced, often classified, materials, MJOLNIR-derived technology would be integrated into wider service throughout the Air Force, Army, Navy and Marine Corps as the war dragged on.

  • UNSC Air Force
    • Pilot - introduced in 2541, the "Pilot" helmet was originally developed as a part of the MJOLNIR Mark IV, including sophisticated digital tracking software for onboard flight controls, selecting, designating and tracking friendly and hostile units, as well as vehicle status and hull/shield integrity.
  • UNSC Army/Marine Corps
    • Air Assault - Originally developed as a replacement for the ODST BDU helmet currently in service, the Air Assault helmet was eventually adopted in 2531 by the UNSC Army, especially among airborne special forces and pathfinder units.
      • Military Police - A basic modification of the standard CH252 combat helmet, the MP variant was tested by MJOLNIR and introduced for military base and starship military police units for improved protection against both ballistic and melee hits. The helmet is also used by UNSC Marine units during boarding operations.
    • Explosive Ordnance Disposal - Given the heavy firepower Spartans often have to deal with, the EOD helmet was developed at the Damascus Materials Testing Facility at Chi Ceti IV, designed specifically for explosive detonation, allowing the wearer to disperse energy from explosives at close range. The helmet itself is specifically designed to prevent decapitation of the wearer. Various components have since been introduced into wider service among the Army and Marine Corps among bomb disposal units.
    • Joint Fires Observer - developed for UNSC Army Joint Fires Observer units, the JFO variant has seen extensive use among Army Troopers in artillery observer roles coordinating long-range UNSC artillery and missile fire, designed to vastly improve the uplink between observer and ground attack fighters/artillery units.
    • ODST Battle Dress Uniform - though the basic outline and appearance of the Orbital Drop Shock Trooper divisions have remained unchanged since the 23rd century, MJOLNIR would radically improve combat survivability, integrating a number of features into ODST BDUs, such as ceramic-titanium composite material and advanced onboard digital software. ODST equipment is fully compatible with MJOLNIR, though remains unpopular among Spartans given the hostility ODSTs traditionally hold towards them.



  • "Take a look at the Mark I/II/III. Now look at the VAJRA prototypes. Any similarities are fully intentional - VAJRA-I was marketed as a full-scale, bigger-budget and higher-effectiveness MJOLNIR. That is, until the Mark IV came along and blew it out of the water. Alas, what might have been..."
  • "Strictly speaking, it's just two models. The first-generation model was big, clunky, a waste of power and far, far, FAR too expensive for the results it produced. The second-generation model was divided into the Mark IV, V and VI only because ONI forced Halsey to use generational increments for standardisation purposes, since they were trying to introduce technology used for MJOLNIR into other service. The last three suits are basically one single series, with increasingly improved components. There's more difference between the Mark I and Mark II than there between the IV and VI."
  • "I remember some bright spark had the idea to stick a Marine in one of the IV's, take it for a test run. Maybe they had brass coming around, and he wanted to show them something worth while? Well, they got their show alright - it pulverised the poor guy to a pulp, and that was before he could even start the test!"
  • "So only Spartans get these? It figures. Faster, stronger, better protection, not to mention vastly superior digital uplinks and energy shields. Of course they go to Halsey's tin soldiers, while the real groundpounders, the men and women fighting and dying for the colonies, get jack shit."