MJOLNIR Mark IV Powered Assault Armour/Vajra II

Most imagine the MJOLNIR project to be a single suit used continuously during the Human-Covenant War between 2525 and 2552. If it is possible for this to be any further from the truth, it is difficult to concieve how, and in hindsight the idea that the most advanced soldiers that humanity has ever fielded would use the exact same equipment for nearly thirty years unchanced is ludicrous. The introduction of the Mark IV was without precedent, perhaps akin to the invention of the lance or the sword; this was unknown territory, revolutionising the already revolutionary way that their Spartan operators were able to wage war, and with it came many problems that nobody could have foreseen, sometimes shockingly so. Field patches were made either by technicians or even by the Spartans themselves for minor glitches and deficiencies, but permanent solutions were needed - with the almost dizzying number of offshoot projects, customised variants, and prototype testbed suits developed as part of the UNSC's various special weapons programs, the Mark IV would end up with almost three dozen different variants. Most of these were single-use prototypes, and many never even saw combat. Others were custom-designed for a number of SPARTAN-II teams, incorporating more advanced, sometimes experimental, technology, than the standard suits. Still more featured functions that would appear in later iterations of the MJOLNIR series, such as early energy shield generators, miniaturised fusion reactors, improved user interfaces and improved processing power, and support for a Seventh-Generation Smart AI. Usually, each function was prototypes with a single suit - the technology to incorporate all of these technologies into a single suit would have to wait until the MJOLNIR Mark V.
The Mark IV/Vajra II variant can be said to be the early forerunner to the Mark V suit, and while it lacked the ability to carry an AI, it was the first combat system to use energy shield technology, deployed in 2531 to mixed results, and again successfully in 2542 - a full ten years before the Mark V would become standard equipment among the Spartan-II personnel. Used by a number of Spartan-II (and later, Spartan-III) teams, the Vajra II was pioneered by personnel from the failed Project VAJRA, and improved on many of the original systems of the Mark IV, developing components and designs that would lead to the development of the Mark V.
==History==
Project VAJRA had seen a large amount of success in its brief life, developing the first powered armour system that was able to be used by unaugmented personnel, allowing a UNSC Marine to operate it. Combat testing showed much promise, and the prototypes were recieved with enthusiasm by the Navy brass. When Doctor Halsey unveiled her MJOLNIR project, however, it instandly spelt doom for VAJRA - a suit so compact, able to instill lightning reflexes, nearly limitless endurance and strength, operating at the speed of thought. The fact that it could only be used by SPARTAN-II personnel was a convenient oversight Halsey deliberately kept to herself until she had got her funding, and by the time ONI realised what it had done, VAJRA had collapsed, its personnel reassigned and its funding reallocated to MJOLNIR.
Many of the scientists and researchers that worked on VAJRA would end up under their nemesis, Doctor Halsey, where they went to work on improvements, upgrades and replacements for the MJOLNIR Mark IV. A sub-section of this new MJOLNIR support group, a number of VAJRA scientists colluded to produce their own variant of MJOLNIR, hoping to incorporate technologies that were at the time experimental. As an affectionate homage to their former work, they codenamed this VAJRA II, with Halseys amused approval.
The technologies that would be incorporated into MJOLNIR were, for the most part, determined long in advance of the MJOLNIR Mark V being introduced into service - while the Mark IV had proven the effectiveness of UNSC fusion reactors, they still lacked the efficiency for their size that would be required for another feature Halsey deemed a must, a full-body energy shield generator. The latter technology would be developed with expertise and resources from Project TEMERITY, a Naval Special Weapons research project, and would see successful trials on Red Team in 2531 during the Second Battle of Harvest in the VAJRA II/A. However, the efficiency of this shield was barely worth the effort of installing it, and Halsey would be reluctant to incorporate the technology until a fusion reactor could be found to properly power it.
VAJRA II would eventually create the ideal reactor, testing it in 2539. Designed using an improved understanding of electromagnetic manipulation derived from salvaged Covenant technology, the new reactor, the VGX-77, was the equivalent of a UNSC corvette, in both power output and efficiency, and in cost, but it would be incorporated into the VAJRA II/D in 2541, and granted to Indigo Team - this was a development Halsey was kept unaware of by ONI, given the hard work they had put into keeping Indigo a secret from her. Deployed in 2542, the V-II/D would prove to be everything MJOLNIR could be - the fusion reactor allowed it to possess the recharging energy shields that Halsey had deemed imperative for the Mark V, and the system would be modified and improved only slightly for the Mark V. Indigo Team would continue operating the V-II/D variant until they acquired Mark V armour in early 2552, again combat testing a technology that other Spartans would not recieve until later.
When the Mark V was introduced, rendering the previous iteration obsolete, many of the Mark IV suits were recovered by ONI and retrofitted with the V-II/D improvements and approved for use by select Spartan-III special warfare operators, the first Spartan-III's to abandon their traditional SPI in favour of full MJOLNIR. The VAJRA-II/E would be developed, incorporating improvements to the active camouflage technology used by the SPI into the suit, allowing the Spartan-III's greater stealth, though this would come at the expense of shield integrity and durability - as a rule, stealth and protection modes were incompatible with each other, forcing the energy shields to be deactivated while the active camouflage was engaged, and vice versa. VAJRA-II/E suits would be used extensively by Fauchard and Baselard teams in 2552, during the Battle of Minorca.
The destruction of Reach in 2552 meant the loss of a major amount of wartime infrastructure, including dozens of special warfare projects. Many of the MJOLNIR scientists had already been relocated to the Songnam testing grounds for the last phases of the MJOLNIR Mark VI, and thus were lucky to escape relatively unscathed. As the UNSC recovered from the devastation of Earth, many of the MJOLNIR personnel were reassigned to other projects that were deemed of top priority for the recovery of the UNSC and UEG. The Vajra-II sub-project was disbanded, its members assigned to artefact retrieval and reverse-engineering teams to make use of recovered Covenant and Forerunner technology, though the armour system would continue to see use by Spartan-III personnel, who rapidly acquired the knowledge to cannibalise spare suits for neccessary maintenance. A small support team was kept online for them, but for the most part the S-III's were on their own, and quickly customised their armour further. During the War of Vengeance, Team Kukri and Baselard teams in particular would upgrade to the MJOLNIR Mark V, a shortage of VI suits preventing them from upgrading further, but the majority of serving SPARTAN-III personnel would continue to use a combination of Vajra-II and SPI hybrids and custom variants.
==Design==
Though part of the MJOLNIR Mark IV series, elements of the Vajra II were radically different. The helmet used would eventually be modified and reused as the standard for the Mark V, though this is more a case of aesthetic preference - in terms of functionality, there was little difference between it and the standard Mark IV. Other helmets would be used as well - the V-II/E used a modified form of the SPI helmet, and specialised Extra-Vehicular Activity variants existed, though they were rarely used. Indigo themselves seemed to prefer the baseline helmet, though Jeremy and Laura would adopt different styles upon upgrading to the Mark VI later.
The body armour itself is significantly more streamlined, with a sculpted chestplate and a slimmer back-mounted reactor. In theory, this was an attempt to see whether slimming the fusion reactor would effect the shield generator - it would later be deemed a hindrance to the shields, preventing its wider adoption by other Spartans. In practice, however, the slimmer design dramatically improved the wearers range of motion, with none of the bulk characterised by normal variants. When the Mark IV had been introduced, nobody had foreseen the need for the suit to track more than a single weapon - carrying one weapon in each hand may look visually impressive, but makes little actual combat sense, given the resulting instability from the recoil and difficulty in aiming. Spartans had no such limitations, but found the software unsuited to the task. The Vajra-II would feature improved subroutines for the suit to identify weapons on the battlefield, cross-reference these against an internal database that was frequently updated as materiel entered service, and in the case of Covenant weaponry, adapting as new materiel was observed and recovered, and adjust the helmet-mounted display's weapon tracking displays and targetting reticule(s) appropriately - features that would be incorporated into the later Mark VI. Coincidentally, this would be a totally convergent development to the VISR pioneered by the Spartan-III VISR system, though the technical similarities cannot be disputed, and the VISR would replace it in the V-II/E variant.
The most important aspect of the Vajra-II, however, are the energy shield generators. Using the improved fusion reactor developed specifically to support it, the V-II/D would be the first powered armour system to use full-body solid light barriers. Energy shields as they are commonly imagined, solid but invisible walls of force, are a myth - concievable a solid barrier could be erected and made invisible, but this would fail to qualify as a shield. Instead, UNSC and Covenant systems make use of electromagnetic forces to produce a powerful repelling force, able to deflect bullets to a limited extent and interfere with the guiding magnetic fields of plasma projectiles. V-II/D and V-II/E systems make use of an alternate system, projected planes of light photons energised to behave as a particle rather than as a wave, creating a full-body protection system. The SLB generators were derived from Forerunner technology, and pioneered by the Vajra-II, and while the performance has been exceptional, the extreme power requirements have been a hindering factor in its adoption throughout the UNSC, and was dropped for later iterations of the MJOLNIR. It has seen successful use in Indigo Team before their adoption of the Mark V and VI, and a number of Spartan-III teams.
===Variants===
Though some teams, such as Black Team, would use suits that were so bleeding-edge advanced that they defied classification, for the most part the Vajra-II sub-project produced a number of variants; some, such as the V-II/B and V-II/C, would result in innovations that would become standard; others, like the V-II/A, were prototypes that, while technically successful, produced results that were underwhelming. The V-II/D was perhaps the most successful, and perfected the reactor technology that made energy shields a feasible concept, and though it was later abandoned by the Spartan-II's, it would continue to see use afterwards in the form of classified Spartan-III operators. The loss of so much personnel and materiel at Reach put an end to the Vajra sub-team, reassigned to the reconstruction effort, and in turn Vajra-II - with no more support personnel, the last Spartan-III operators were forced to cannibalise spare suits for parts and conduct their own field maintenence, producing further customised suits.
*Vajra-II/A - though begun immediately after the encounter with the Covenant at Chi Ceti, the V-II/A variant would only see its field testing in 2531, long after the V-II/B had become successful. Though it was the first to incorporate an energy shield design, in this case the Solid Light Barrier, it was woefully inefficient, both in terms of protection and energy consumption, and reactor technology at the time did not yet exist for improvement. The only prototypes were lost when the original Spartan-II Red Team became Missing In Action, but ONI considered it no major loss, at least in terms of the equipment.
*Vajra-II/B - introduced in 2527, the V-II/A featured improved integrated weapon operation software. The use of standard UNSC weapon software was seen as a logical choice - it was already uploaded with schematics and details for the operation of all UNSC standard firearms, and included targeting software for its operation preloaded. Its use by Spartan-II personnel raised serious issues - for one thing, it was woefully under-developed for the new Covenant technology that would be encountered, with no pre-existing software to support its integration and operation. For another, the use of smaller, lighter weaponry one-handed, such as the M6 pistol and M7 submachinegun families, was something that had never been considered. The V-II/A software would rectify these problems, and the improvements would become standard on MJOLNIR for the next thirty years. 
*Vajra-II/C - a dedicated EVA variant, the V-II/C was developed as a response to the Groombridge 34 incident of 2531, intended to improve the efficiency and safety of extra-vehicular activities - losing a Spartan in a space operation had shaken ONI, especially given just how effective they had proven to be as a morale boost, and while ONI Directive 930 would keep up the illusion of Spartan immortality, ONI were loathe to let the incident repeat itself. The V-II/C variant had an integrated thrust-vectoring pack attached to the pack, custom-designed for Spartan-II use, and able to be easily jetissoned in the event of malfunction. Furthermore, broadcast equipment for an emergency signal on encrypted UNSC channels was included, and the chestplate included a length of steel rope with a magnetic clamp attached, able to be easily attached to a nearby static ferrous object to provide stability until recovery.
*Vajra-II/D - while the V-II/A would be deemed a tentative success, Halsey was unhappy with the results, and ordered more focus placed on development of a sufficient energy source. Innovations provided by Project TEMERITY as part of its cooperative development of various energy shield technologies would prove the breakthrough needed, and the V-II/D would be the first successful deployment of powered armour. Successfully field tested by Indigo Team over a decade, the V-II/A would be successively improved as the UNSC's understanding of shield systems improved, and plans were made to make the system standard for MJOLNIR Mark IV - the introduction of the Mark V rendered this obsolete, though it would prove a godsend for the V-II/E.
*Vajra-II/E - unlike its predecessors, the V-II/E was developed solely for Spartan-III operation, and made use of the nearly two dozen superfluous Mark IV powered armour suits left during the Spartan-II's adoption of the Mark V. Though Halsey preferred the electromagnetic shields used in the Mark V and VI, the V-II/E would continue to use the solid light barrier system pioneered by the V-II/A and perfected in the V-II/D. Other technologies were also incorporated into it - the uploading of the SPI VISR notably, a drastic improvement over the standard targetting software, as well as the inclusion of photoreactive panels and stealth metamaterials to improve its active camouflage capabilities. The power supply proved insufficient for both shields and camouflage to function concurrently, though upgrades were planned to remedy this, and the metamaterials used were deemed inefficient, expensive, and far too fragile for combat wear-and-tear, complaints that the Spartan-III's overlooked as they became accustomed to its reaction, speed and strength enhancements - all relatively standard on MJOLNIR, but still new to the Spartan-III's. In 2556, all solid light barriers on the V-II/E variant were replaced by electromagnetic shields, marking the end of such technology as personel energy shields for powered armour.
*Project: HELLSPARTAN - Technically, Project HELLSPARTAN was a separate offshoot of Project MJOLNIR, separate from Halsey's oversight and independently run by the UNSC Navy, and was entirely a testbed prototype. Much of the hardware was borrowed from the VAJRA-II sub-Project though, and integrated into prototype MJOLNIR Mark VI/V armour for testing on Spartan subjects. The enhancements included boosts to the momentum-amplifying liquid crystal layer, upgrades to the MJOLNIR/Neural Interface connection, and a visual scheme intended to confuse enemy combatants, known as "Armor Livery Dazzle Camo." Numerous problems were found during testing - the "improved" crystal layer proved too much for two of the Spartans, not helped by the improved neural pathway uplink to the suit - the reaction times for the Hellspartan armour was simply too high for even Spartans to easily adapt to, and the other two test candidates adapted only with great difficulty. Further, the visual scheme was found to be difficult to camouflage - while it certainly served its purpose, confusing or intimidating enemy combatants long enough to give the wearer an edge in close-quarters battle, it gave itself away in optical camouflage. Further, the new crystal layer produced excessive thermal energy, difficult to mask and exposing the wearer to uncomfortable temperatures and the risk of equipment malfunction. These problems would eventually be solved by the time the MJOLNIR Mark VI series entered full combat service on remaining Spartan-II personnel. Little is known about what happened to the original Hellspartan suits - they may have been cannibalised for parts, modified and used by Spartan II's as conventional MJOLNIR, or even used as they were by classified Spartan II or III teams. It would certainly not be the first time advanced hardware has found its way to combat units deemed secret even by Spartan standards.
==Operators==
===Spartan-II===
*Red Team (2531-????)
**Jerome-092
**Douglas-042
**Alice-130
*Black Team
**<\ CLASSIFIED: NOVEMBER BLACK \>
*Indigo Team (2542-2552)
**Andrew-306
**Laura-125
**Jeremy-068
===Spartan-III===
*Anelace Team
**<\ CLASSIFIED: NOVEMBER BLACK \>
*Baselard Team
**Julie-B224
**Erin-B016
**Reginald-B302
*Hachiwara Team
**<\ CLASSIFIED: NOVEMBER BLACK \>
*Kukri Team
**Li-B306
**Sarah-B102
**Jennifer-B313 
**Oliver-B112 
**Kenneth-B142
**Nathan-B266
**Grant-B239
*Fauchard Team
**Lileas-G332
**Wiremu-G402
**David-G017
**Michael-G111
==Quotes==
*""Vajra" was our little joke, I suppose. A lot of us liked to imagine that the first project had managed to survive, and we regarded the Vajra-II variant of the MJOLNIR as an extension of the work we would have done anyway - the fact that we reported to Halsey, who shut us down in the first place, was a minor consideration."
*"Considering the personal interest Doctor Halsey takes in her projects, its amazing the Vajra crew managed to keep its cooperation with Indigo Team secret. If she'd ever learnt there were Spartans off the grid, she would have gone bananas - I shudder to think what her reaction to the Spartan-III's would have been."
*"Solid Light Barriers may be more durable than the magnetic shields standard MJOLNIR uses, but the power consumption doesn't make it worth it. For starships, sure - but for small, mobile warfighters? Its just an inefficient waste. I don't regret switching to the Mark V - I just wish there were enough Mark VI's for all us survivors."
*"We wondered for a while whether the expansion of the system to non-Spartans was a worthwhile avenue to pursue, but Halsey put a stop to that. I think she saw it as compromising the integrity of the suit, "cheapening" it for regular humans. Personally, I always thought she took an unhealthy interest in its development - but what else did she have to do after the Spartans were activated for duty?"
==Behind the Scenes==