The UNSC Navy and Marine Corps upper echelons have always had a very clear idea of what Powered Armour should be - compact, producing extreme strength, speed and endurance, compatible with most service personnel, and above all cheap. While the MJOLNIR Mark IV met many of these requirements, it is anything but cheap, and required augmented SPARTAN-II or III personnel to operate without producing lethal side-effects of the force-multiplication and reaction amplification; and while the Cyclops exoskeleton fell well within the price range of UNSC HIGHCOM, and available to most personnel with little training, its performance record leaves much to be desired. As Doctor Halsey's own iteration of Project MJOLNIR entered its last stages of the Mark IV prototypes, HIGHCOM commissioned a second project to develop an effective combat assault exoskeleton for use by UNSC personnel.
In many respects, Project VAJRA was an imitation of past attempts. Most of the developers were formerly part of Project CYCLOPS, and put their experience to effective use. While MJOLNIR would pioneer the use of advanced materials, such as the high-density alloy used for ballistic and DEW protection and the momentum-amplifying liquid-crystal layer, VAJRA used off-the-shelf technologies to cut costs, updated to take innovations made after the Cyclops into account. Lessons were learned from the Cyclops - rather than focus on brute strength and bulk, combat powered armour needed to improve the wearers speed and agility, two factors that the Cyclops lacked in any amount. The design was streamlined to a basic human figure - the design allowed a better range of mobility than the Cyclops, and strength and speed were augmented by an array of mechanical muscle-analogues controlled by a Third-Generation "Smart" Artificial Intelligence, the first such use of an AI by a single warfighter, and the only such use until the introduction of the MJOLNIR Mark V. The later iterations would utilise a similar AI support system, though the two were developed along radically different lines of thought - the AI core was built right into the VAJRA armour, rather than serving as a temporary home for a removable AI data chip. The result was impressive - physical performance was enhanced dramatically, with virtually unlimited stamina, and the whole suit was protected by a layer of ceramic-titanium composite ballistic armour, with additional thickened plates surrounding the fusion reactor and AI core, the two most vulnerable parts of the suit. In combat deployments, the suit performed superbly, greatly impressing Naval and Marine spectators, and word even reached members of the UNSC Army and Air Force, both branches expressing interest in the development of VAJRA.
The VAJRA never entered combat service, with the project ending in 2524 due to budget restrictions by FLEETCOM. The VAJRA had proven to the UNSC that the potential benefits of researching powered armour was enormous, and had produced interest in other suits, such as the MJOLNIR and SPI - ultimately, though, this would be the doom of VAJRA. The promising development of the MJOLNIR Mark IV under Doctor Halsey was enough to convince the Admiralty that one design was sufficient for their needs - the considerable expense and limited availability of the MJOLNIR were facts that Halsey kept very quiet, until she had already acquired the funding and support she needed to continue. Members of the VAJRA development team requested combat trials of the two prototypes, the Jīngāng and Dojê, in an attempt to prove the effectiveness of the armour, but their initial attempts were met with a wall of dismissal - that all changed when the attack on Harvest reached the UNSC. Suddenly facing an unknown enemy of significant technological sophistication, HIGHCOM became very keep to pursue every avenue of development available to it, and permission was granted to VAJRA for the deployment of the two suits.
Corporal Grant Wallace and Private First Class Amanda Vasquez were selected to be the operators of the suits, and they saw deployment on a several worlds in 2526, including Lefenyal, where the two NavSpecWar operators would assist in the battle for the colony and the evacuation of the city. Each suit was equipped with a handheld M224 Machine Guns, shoulder-mounted 20mm railguns, ventrally-mounted flare pods, and wrist-mounted fragmentation and flash-bang grenade-launchers, as well as numerous ammunition compartments to supply the weapons - together, Wallace and Vasquez would almost single-handedly fight a Covenant company to a standstill as Marines evacuated the capital city, Etaredom, and came close to assassinating a Covenant Prophet. While the design certainly proved effective, flaws emerged - the sophisticated mechanical augmentations defied frontline maintenance, and the interface between the AI and wearer proved less efficient than developers had expected, a flaw that would be smoothed out by the time the MJOLNIR Mark V came into use. Ultimately, however, it was internal differences between factions in the Navy that saw the final demise of the VAJRA project, and its funding was diverted to the MJOLNIR, SPI and HAYABUSA projects. Members of the project would eventually findthemselves reassigned to other NavSpecWep research efforts, though Halsey requested many for MJOLNIR - a small sub-project would eventually form, intended to research cutting-edge enhancements and upgrades for the MJOLNIR Mark IV, named VAJRA-II by its members out of affection for the failed project. The VAJRA-II improvements would influence the MJOLNIR Mark V and Mark VI, sometimes vitally - the AI support system, though using a different design altogether, was inspired by the potential of the VAJRA.
Officially, the two prototypes were donated to the Elysium Military Museum, where they were displayed as forerunners to the MJOLNIR, a fact that irked designers on the project. Unofficially, it was rumoured that these two were mock-ups of the actual suits, which continued to be used in covert operations by operators of Naval Special Warfare, or were used as testbeds for developing technologies and equipment for other research projects. Certainly, the data crystal AI support system would play a heavy role in the development of the MJOLNIR Mark V, and were used in the prototype Vajra-II/B and D suits used by Indigo Team, allowing them to carry an AI during combat operations. If the rumours are true, then their eventual fates are unknown - some posit that the powered armour seen on Algolis was a derivative of VAJRA, though its capabilities, and scale, make the VAJRA suits pale in comparison. Others insist that they must have eventually been destroyed in combat, or are still in active service. The record is not helped by the constant and, in most cases, inaccurate sightings of "Spartans" in combat - some of these reports are ONI fabrications to boost morale and help build the Spartan Myth, while others are genuine reports of anomalous personnel. Some of these may even by sightings of VAJRA armour in combat - to an untrained eye that has never seen a Spartan in full MJOLNIR before, the differences would be indistinguishable at range.
- "I saw it during the Lafenyal Campaign - seven feet of pure ownage. At the time, I didn't know what a Spartan was - If I had, I would have said that it was one of them."
- "Its not as strong or fast as MJOLNIR, and if they'd tried to put a shield generator on it the whole thing would have toppled over. I wish the Marines had at least a few dozen more of these, though - maybe then we wouldn't be so legendary. The spotlight gets so tiresome, thanks to Section II."
- "They say there were two of these on Reach, sitting in display cases, when the Covies burned CASTLE BASE. Geez, its not like we couldn't have done with them! Or were they just hollowed-out husks? You can never quite tell with museum pieces."
- "There's a number of official reasons, but unofficially, I've heard that the main reason it was retired before it had even started was because it would have killed the "myth" of the Spartans - if anyone could be a supersoldier, then the morale boosting implications of the Spartans would have been nil. I guess that's military politics for you. Rather than fund the suit that anyone can use, and that everyone wants to use, they fund the one that needs years of harsh training and surgical and cybernetic augmentation. Jerks."