Power Armour

Power Armour is an form of powered combat armour primarily worn by the Adeptus Astartes. It is a completely enclosed suit of armour composed of shaped Adamantium and Plasteel plates, encased in Ceramite ablative layer. Each suit possesses a full suite of ife-support functions for operations in hostile enivornments, an automated medication system to provide some level of first aid to the occupant and a highly advanced and fully integrated tactical targeting and threat analysis system known as Auto-sense. The suit would be heavy and cumbersome to wear but with the electrcally motivated fibre bundles within the armour that replicates the wearer's movement and enhances his strength byong its already considerable superhuman baseline. despite commonly worn by Space Marines, other bodies of the Imperium of Mankind also wearn some variations to power armour, however they do not posses the same level of protection and life support systems.

History and Development
Power Armour has been in use since before the Age of the imperium, worn by the techno-barbarians that dominated Terra during the Age of Strife. It was also worn by the early genetically-engineered warriors that formed part of the Emperor's retinue during his unification of Terra towards the end of the Age of Strife in the 30th Millennium. In the armour's earliest incarnation, the suit was not fully sealed or life-supporting, this being unnecessary while its use was still confined solely to Terra. Over the history of the Imperium, Power Armour has developed into many different forms. Need, circumstances and the recovery of new materials and lost technology, so called Archeotech, has shaped the armour's evolution.

Each new form of the original Power Armour redevelopment was categorised with a mark. Whilst it was common for the Astarte Legions to adopt the newest marks of power armour, certain marks were created to fill a specific niece in the combat effectiveness of each legion's combat doctrine. Currently in the 31st Millenium, 5 marks had been developed since the middle of the Imperium of Mankind's intended civil war. Each having distinctive differences between the other respectively.

Mark I - Thunder Power Armour
The first Power Armour suit type created for the Space Marines was the Mark I Thunder Power Armour, though the name was assigned after the fact and at the time of its use the suit was simply called "Power Armour." It was developed from the powered combat armour adorned by the techno-barbarians that plagued Terra near the end of the Age of Strife. It was used during the Emperor's campaign to reunite the Sol system before the Great Cruade. It was no not unique to the first space marines as in fact, the techno-barbarian warriors the Emperor fought during the conquest of Terra wore it also, and the Emperor's forces of genetically-enchanced warriors were wearing it even before the first true astartes were developed.

However, because it was designed with fighting in a terrestrial environment in mind, it as never made fully enclosed, with no means to support the wearer in a vacuum. Only the upper body is powered, due in part to the fact that during the Emperor's conquest of Terra, ranged weapons were difficult to make due to technological constraints, and so a warrior's upper body strength was his most important asset.

This armour mark takes its name from the thunderbolt and lightning symbol the Emperor used during the Unification Wars before he adopted the "Aquila" during the Great Crusade. The emblem gave the suit its present day name - ''Thunder Armour. ''This early armour was produced on a completely local basis. There was no standard design, indivudal suits varied heavily and their exact designs were often a matter of personal taste. The main part of the armour is the massive powered torse which enclosed the chest and arms. Coiled energy cables beneath the armour plating transmit energy from the power pack on the back to the arms. Greatly increasing physical strength.

Mark II - Crusade Power Armour
Mark II Power Armour was developed towards the end of the Age of Strife and was used during the dawn of the Imperium by the Space Marines who carried out the Emperor’s Great Crusade to reunite the lost colony worlds of Mankind in a new Imperium of Man. After the conquest of the main planets of the Solar System by the Emperor's new armies of Space Marines, the Adeptus Mechanicus factories on Mars were set to work constructing a new and far more advanced type of Power Armour for the Emperor's newborn Space Marines. This armoured suit is commonly referred to as "Crusade Armour," since it was designed with the planned Great Crusade in mind. It was the first fully enclosed suit of Power Armour, making it suitable for the conquest of space and operations in a vacuum. It was designed as a fully enclosed suit with life-sustaining systems that now allowed the Astartes to fight in deep space and on alien worlds with hostile atmospheres or environments.

The armour was made up of microscopic circular armoured rings of ceramite fitted under and over each other, making this armour relatively tedious to repair. The larger armour plates composed of these microscopic rings were linked together to allow for a greater ease of movement and most of the power cabling for the suit was threaded inside the plating. The backpack retained a similar shape to that of the Mark I suits but now contained advanced life support equipment such as air-scrubbing, fluid recycling and emergency medical first aid systems as well as the power supply for the armour. The helmet was set in a fixed position, but did allow the occupant to turn his head inside the suit. The helmet also contained electronic sensory devices and miniaturised cogitators (computers) that monitored the surrounding battlescape and fed visual and auditory signals directly to the Astartes' cerebral cortex through a neural feedback mechanism. This further enhanced the Astartes' already superhuman sight and hearing, while at the same time dampening any blinding flashes or deafening explosions. These so-called "autosenses," as well as the other internal improvements, all became standard equipment in every subsequent pattern of Imperial Power Armour. At the present time, these suits of Power Armour are extremely precious relics of the few Chapters that still possess a suit or two and are still used during formal ceremonies and rituals by some Chapters. These suits are often given to the Chapter's champions as actual battle armour in others. Though quieter than the Mark I, Crusade Armour also is not intended for stealth, though the sight of an Astartes wearing this armour draws every Space Marine's mind to the glory of the Great Crusade before the disaster of the Horus Heresy and provides a major enhancement to unit morale.

Mark III - Iron Power Armour
As the Great Crusade reached the planets towards the core of the galaxy, some of the worlds encountered were the Squat homeworlds, which were not pleased to find themselves the object of a galactic conquest, Emperor of Mankind or no. The Squats' independent and stubborn nature along with the conditions of the fighting in the Squats' underground cities spurred the creation of this new armour type. High casualties suffered by the Legiones Astartes on these worlds and in other similar environments such as during boarding actions during the Great Crusade led to the development by the Adeptus Mechanicus of the Mark III model of Power Armour. The Mark III was best suited for spacecraft boarding actions and combat in confined subterranean tunnel complexes with little cover. This armour was ideally used by Space Marines when cover was minimal and combat was a matter of a simple frontal assault. Because of this pattern of Power Armour's great strength, it became known as the "Iron Armour" or Armorum Ferrum in Imperial High Gothic.

The Mark III was never intended to replace the Mark II armour but instead was a specialised suit to provide heavier protection than the normal Mark II suit when fighting in conditions similar to that found on the Squat homeworlds, in mines, subterranean complexes or the tight corridors of a spacecraft. It has more frontal protection than the Mark II Armour, but the weight of the rear armour was lessened to compensate. The suit uses a heavy armoured helmet with sloping plates designed to deflect shots to the left and right, thus inspiring its name as the Iron Armour pattern. The helmet inspired the Mark IV and VI helmet designs. The wedge-shaped helmet (designed to deflect incoming fire from the front) formed the basis for the later distinctive Corvus Beak helmet of the Mark VI pattern. Iron Armour clanks and grinds with the slightest movement, making it all but useless in stealth operations. However, the presence of such an imposing and ancient suit of Power Armour is a great honour for all Space Marines and can greatly boost unit morale in combat.

Mark VI - Maximus Power Armour
As the Great Crusade reached its climax and the Imperium reached its zenith in terms of technology and strength, the Space Marine Legionsfound their original suits of Mark II armour wearing out. While some Legions chose to continue local production and maintenance, the Adeptus Mechanicus of Mars designed a new variant, which was to be called the Mark IV or Maximus pattern since it was produced during the days of the Imperium's greatest glory.

At the Mark IV stage of Power Armour development, Space Marinearmour began to take on an appearance recognizable to that of contemporary Power Armour patterns, its primary change being the abandonment of the separate abutting plates of armour in favour of larger, inflexible armour casings incorporating flexible joints. This marginally reduced an Astartes' mobility but was far easier to produce and maintain, and the suit was actually lighter and provided its wearer with more overall mobility due to the lessened weight, while not reducing the actual level of protection the suit provided compared to its Mark II counterpart.Technical secrets from the Dark Age of Technology recovered on newly conquered worlds during the Great Crusade allowed the Mechanicus of Mars to develop the more efficient mark of armour, improving the quality of protection and reducing the suit's weight at the same time. Improved armouring of the suit's power cables allowed the main arm and chest power supply cables to be safely relocated to the exterior of the armour, while the use of new materials reduced the size and number of cables. The various systems contained within the suit's backpack were miniaturised and made more efficient, allowing the backpack to be smaller, lighter and to make use of an altered exhaust system that provided a shape much closer to that of the Mark VI and Mark VII patterns of armour in widespread use at the present time.

The Mark IV suit's helmet was a completely new design, the basic shape inspired by the sweeping front of the Mark III. In Mark III and later versions the helmet was no longer fixed to the armour's neck plates, but moved with the wearer's head while still maintaining an environmental seal. This advancement represented the Artificers' increasing experience with neural connector gear and the new materials which flooded into the Martian workshops as the Great Crusade progressed.

Whilst standard patterns of armour were shared across the Space Marine Legions during the Great Crusade, variations on these templates surfaced in most of the Legions. Mark IV Achean Pattern Power Armour arose as a local variation of Mark IV Maximus Power Armour, produced for the Thousand Sons Legion by the forges local to that Legion's homeworld of Prospero. More stylised than their standard armour, Achean Pattern battle plate was most often worn by XV LegionVeterans.

Mark IV Power Armour was envisioned at the time to be the ultimate and final type of Space Marine armour, able to offer the best protection in a variety of conditions. Many of the Space Marine Legions were entirely or partially re-equipped with it by the start of the Horus Heresyin the early 31st Millennium. As a result of its widespread production and use prior to and during the Horus Heresy, Mark IV suits are the most common of the pre-Heresy armour patterns still in service with the Adeptus Astartes of the late 41st Millennium. Mark IV armour was envisioned at the time to be the ultimate and final type of Space Marine armour, able to offer the best protection in a variety of conditions. As a result of its widespread production and use prior to and during the Horus Heresy, Mark IV suits are the most common of pre-Heresy Power Armour Marks still in service during the 41st Millennium. Notably, a few Chapters, such as the Red Scorpions and Iron Hands, are still capable of producing new Mark IV suits in the 41st millennium.

This pattern of armour is the type of Power Armour still worn by most of the original Chaos Space Marine Traitor Legions, as they usually have access only to the technology they took with them into the Eye of Terror ten millennia ago. However, some Chaos Space Marines mix and match more modern pieces of armour with their ancient Mark II and Mark IV suits to replace damaged portions. Those Space Marines who have turned Renegade since the Horus Heresy obviously wear the Power Armour that was current to the era when they first turned against the Emperor. Chaos Space Marines often strip more modern pieces to upgrade their armour from the bodies of Loyalist Space Marines killed in battle. Among Loyalist Space Marines of the late 41st Millennium, being granted the right to wear a suit of this ancient form of Power Armour is a great honour and such an Astartes will be given greater respect than normal by his fellow Battle-Brothers and Space Marines from other Chapters.