The MJOLNIR Powered Assault Armor/Mark V was the second major version of the MJOLNIR Powered Assault Armor series. The initial version of the Mark V powered exoskeleton, designated as Mark V[B],[1] was issued to the SPARTAN-IIs and several SPARTAN-III commandos on November 24, 2551,[2] while the second version of the armor was unveiled for Operation: RED FLAG on August 29, 2552.[3][4][Note 1] The Mark V armor was in service until October 2552, when it was replaced by the MJOLNIR Mark VI.[5] It could still be requisitioned by SPARTAN-IV personnel as late as October 2558, albeit upgraded to function with the MJOLNIR [GEN2] suite.[6][7]

Contents1 Development history and design2 Armor variants2.1 GEN12.1.1 Known variants2.1.2 Mark VI prototype2.1.3 Supplemental armor and accessories2.1.4 Attachments2.1.5 Mark VI upgrade2.2 GEN22.2.1 Known variants2.3 GEN32.3.1 Known variants3 Upgrades4 Armor components5 Performance and durability6 In-game information6.1 Halo 3 - GEN16.2 Halo: Reach - GEN16.3 Halo 4 - GEN26.4 Halo Infinite - Upgraded GEN17 Production notes8 Gallery9 List of appearances10 Notes11 SourcesDevelopment history and designIn 2542, seventeen years after the MJOLNIR Mark IV entered service, production began on the next generation of MJOLNIR armor. A team under the leadership of Chief Scientist Dr. Catherine Halsey would spend the next ten years developing the suit. Using data collected from the Mark IV, hundreds of minor technical improvements and several major changes were made to the Mark V; most notably, the suit's armor plating underwent a total redesign and better materials were developed for its use. Separating the Mark V from the previous version of the system were two major breakthroughs in the ways in which the suit improves its wearer's combat effectiveness.[4]

The first major breakthrough, which was introduced with the first generation of the Mark V, was the addition of a self-recharging energy shield system, reverse-engineered from captured Kig-yar point defense gauntlets,[8] which repel objects and energy bursts, plus any other hazardous elemental energies. While impacts on the shield place a substantial drain on the system's power supply, the system's energy regenerates once the user is no longer under fire. However, the adaptation of the shield covering the entire body weakens the magnetic field, making the Mark V's shield system vulnerable to sustained fire. Energy shield technology was first tested on the Mark IV, though such tests were not especially successful.[3][9]

The second major advancement, which was not implemented until the second generation of the suit,[3][4] was the addition of a layer of computer memory superconductor that would allow an artificial intelligence to piggyback into the field with the operator to both provide and gather real-time intelligence. The synthesis of an artificial intelligence with a human brain is not possible without an upgrade to the user's already-specialized neural interface. Like the standard neural interface, the specialized neural lace translates electrochemical signals to digital code and routes them through an interface connection at the rear of the skull. Through this interface, the user's thoughts command the armor's movement and weapons, and input from the on-board sensors is fed directly to the user's mind. In addition, an AI personality and processing matrix can be carried by the armor and delivered to the suit via the specialized neural lace and on-board storage in a crystal data chip no larger than a personal credit card. Without the armor, a Spartan's reaction time is charted at twenty milliseconds; with the Mark V, and an AI on-board, the time required to translate thought into motion is rendered almost instantaneous.

The suit also possesses other upgraded features that enhance its wearer's abilities. It has an upgraded heads-up display linked to sensors that project shield strength and an improved motion detecting system in addition to providing other numerous readouts, including allies' vitality and shield status. These features are maintained and initialized by the Mark V BIOS firmware.

In its second phase, the Mark V MJOLNIR battle armor weighs 321.3 kilograms,[10] The SPARTAN/MJOLNIR combination is designed to be the most devastating intelligence tool ever created, as the AI can greatly increase the wearer's reaction time and vastly improve intelligence gathering capacity.

John-117 was the first Spartan to test the second-generation MJOLNIR Mark V with a smart AI implemented within the armor during a live-fire combat scenario.[3] His test was to ring a bell after going through an obstacle course. This course involved ten Orbital Drop Shock Troopers, a minefield with Lotus anti-tank mines, three automated 30mm chain guns, a forest of wooden poles, and an unexpected SkyHawk jumpjet utilizing four 50mm cannons and Scorpion missiles. This test showed that an AI could vastly improve the armor's reaction times.[8]

After the Human-Covenant War, the Mark V MJOLNIR components were adapted for the use of the SPARTAN-IV in the MJOLNIR (GEN2) armor. The GEN2 variant of the Mark V was tested at the Damascus Testing Facility in Vhalkem on Chi Ceti IV, a significant MJOLNIR development site for several decadesHelmet: The helmet is one of the most crucial aspects of the MJOLNIR system. It is made of titanium and contains key features like a heads-up display that links to the brain and hands, and can identify equipment and display information about it when it is picked up by the wearer. The helmet also contains other equipment to protect and aid the user in hostile conditions. This includes filters to remove toxins from the atmosphere, a supply to provide air to the wearer during EVA, thermal and motion sensors, communications, solar-powered lighting, and imaging and video gear. The helmet also contains the AI housing, where a ship-borne AI chip can be inserted, located on the back of the helmet. The Mark V helmet is an upgraded version of the Mark IV helmet, modified to function with the Mark V's energy shield systems,[18] though, like the rest of the Mark V system, it likely incorporates several other changes as well. The helmet supports various external upgrades, such as a Command Network Module and Up-Armor plating.Titanium alloy outer shell: The outer shell of the MJOLNIR armor is comprised of a fairly thick titanium alloy. This plating covers the chest, arms, hip, legs, calves, feet and hands. This alloy is very resilient, can take significant punishment, and is nearly impervious to small arms fire. While enough shots from armor piercing rounds will breach the outer shell, the suit can take a few glancing blows from them without compromising the armor. The outer shell of all the MJOLNIR suits is covered with a refractive coating to help disperse the heat experienced from Covenant energy weapons. However one or two direct hits from any Plasma weapon will compromise the armor plating.Titanium nanocomposite bodysuit: Sandwiched between the external armor and the internal padding is a thick black armored bodysuit. This suit has numerous functions, small but vital to the safety and survival of the wearer. The bodysuit is made of a titanium-based material, making it very strong and yet very flexible. It also serves as another layer of protection against ballistics attacks and is coated with a heat resistant material to disperse heat from plasma weapons.