Imperial Military Technology - Power Armour: Possibly the most prominent feature of the Adeptus Astartes is their power armour, a suit of ceramite plates with artificial myo-fibre bundles and mechanical servos that replicate the wearer's movements and enhances a Space Marine's already superhuman strength, as well as allows them to easily withstand environmental conditions and enemy fire that would kill a normal human. The suit is directly linked to the nervous system of the Space Marines via the Astartes' Black Carapace implant. There are nine notable versions of Space Marine power armour to have been used by the Space Marines throughout Imperial history.Mark I Thunder Power Armour - The first power armour created for the Space Marines. It was developed from the armour worn by the techno-barbarians that plagued Holy Terra near the end of the Age of Strife. It was used during the Emperor's campaign to retake and unite the Terran solar system before the Great Crusade. It was by no means unique to the first Space Marines - in fact, the techno-barbarian warriors the Emperor fought during the conquest of Terra wore it too, and the Emperor's forces were wearing it even before the first Space Marines were developed. However, because it was designed with Earth-fighting in mind, it is not 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 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. It takes its name from the thunder symbol the Emperor had before adopting the double headed eagle.Mark II Crusade Power Armour - This pattern of power armour was developed towards the end of the Age of Strife and was used during the dawn of the Imperium in the Emperor's Great Crusade to retake the lost worlds of man. It was designed as a fully enclosed suit with life-sustaining systems that now allowed the Space Marines to fight in deep space and on alien worlds with hostile atmospheres or environments. The armour was made up of circular armour rings fitted under and over each other, making this armour relatively simple to repair (similar in principle to the Lorica segmentata used by the legions of the Roman Empire). These precious relics are still used during ceremonial procedures by some Chapters and given to champions as battle armour in others. These suits are also referred to as Crusader Armour.Mark III Iron Power Armour - With this pattern of power armour it was soon realised that fighting in the tight corridors of spaceships was very dangerous. The Iron suit was designed to give greater protection to the Marines. The frontal armour was much thicker (thereby giving greater protection), but the rear armour was thinner to compensate. The wedge-shaped helmet (designed to deflect incoming fire) formed the basis of the distinctive Corvus beak helmet.Mark IV Maximus Power Armour - This pattern of power armour was to be the replacement for the old Mk2 armour of the Great Crusade; it was the first armour to incorporate many components used in modern armour. However, it was made from rare alien materials, and when the Horus Heresy broke out soon after it was issued, it was discovered that most Legions cut off from supplies could not find the materials needed to make it or repair it, and they often suffered irreparable damage by relatively minor battles.Mark V Heresy Power Armour - This pattern was developed as a solution to the supply problems of the Horus Heresy. It was easily made from the most basic of materials, and it was easy to maintain. Almost all soldiers used spikes to hold the armour layers together, making the studs shown universally on all examples of this armour. In time, it became traditional for the studs to be found on the head, lower legs, and left shoulderpad of the armour. Due to the sub-standard materials used in the construction of this armour variant, it had a tendency to over-heat quickly, and many Marines had to endure sub-standard performance by turning down the power output of their backpack to prevent intolerable heat build-ups.Mark VI Corvus Power Armour - This classic variant of power armour can be traced back to the time of the Horus Heresy and is still commonly used in contemporary Chapters. It is characterised by the beak-like muzzle on the helmet and a studded auto-reactive shoulder plate on the left shoulder of the armour. The beak or muzzle led fans to nickname this variant "Womble armour" or "Beakie armour", and a dictionary of the Orkish language in the 2nd Edition Ork codex listed Marines as "beakies". This was the style of the first Space Marine models released by Games Workshop and did not get its Mk6 terminology until after models with the Mark 7 styling were released. Models with this style were not part of new releases until the launch of the next range of 28 mm plastic models.Mark VII Aquila Power Armour - Also known as Imperator armour, is the contemporary variant most commonly used by the Space Marine Chapters. Characterized by the grim looking Vox Caster (external vocaliser) on the faceplate, and the plastron displaying the Imperialis (a winged skull), which has given the armour different names such as Armorum Imperator or Eagle Armour ("Aquila" being the name of the two-headed eagle which symbolizes the Imperium). A variant of the Aquila helmet is known to exist, yet is no different from the regular helmet, save an armoured trim around the external vocalizer.Mark VIII Errant Power Armour - This pattern is an update to the Mark VII Aquila pattern armour, and is distinguished by a raised collar at the front and armoured plating for the torso power cables. Full versions of this armour are almost never seen; however, it is common to find parts of it being used by Astartes officers and Veterans on the battlefield.One design feature of Marks VI through VIII of power armour is their adaptability; it is fairly common within most Space Marine Chapters to see a suit combining parts originally created for three or four suits, salvaged from dead brothers on the battlefield. Mark VII armour, in particular, was created with this simple modularity in mind.The Sisters of Battle and several high-ranking members of the Inquisition also use power armour, but they are not directly linked to their suits in the way Space Marines are, which decreases the armour's effectiveness.