Under the slogan of a new nationalism raised by Zeon Zum Deikun, who advocates a living sphere to be managed by space immigrants, the Principality of Zeon, located in Side 3, seeks autonomy as a space colony nation, and the Earth Federation government. was steadily preparing to implement the Declaration of Independence against In the background, it is thought that the discovery of Minovsky particles that affect electromagnetic waves in UC0065 made the conventional weapons control system completely meaningless, and that this was one of the reasons for the action. It is the neutralization of the electronically guided weapons that dominated the old-fashioned military. For the Principality of Zeon, which was expanding its hegemony in outer space, the fact that the basic concept of such armaments changed completely, the existence of these Minovsky particles brought about a major turning point in the direction the nation should take.
The Zeon National Defense Forces secretly expanded their armaments and began developing weapons that seemed most suitable for the situation in which they had no choice but to rely solely on visual combat. It is about UC0071. Various industrial equipment manufacturers scattered throughout the Principality of Zeon were asked to make proposals as confidential projects. Based on the exoskeleton-type humanoid heavy machinery that had been manufactured as a machine, he submitted an astounding plan, and upon receiving approval, immediately began developing a prototype. It was a humanoid armored work machine = mobile suit with a total height of more than 10 meters (competitor MIP's MIP-X1 was designed as a medium-sized armored combat boat). At this time, the Public Relations Department of the Principality of Zeon publicly announced it as a large heavy machine for outer space work ZI-XA3, but in reality the Zeon Defense Forces gave this machine the official name of MS-01, and various While searching for suitable applications, improvements were added one by one.
In the first stage of the development of this anti-Minovsky particle weapon, the direction was decided that a completely new armored mobile fighter capable of not only close combat but also hand-to-hand combat would be suitable because long-distance attacks were difficult. However, the humanoid walking mobile weapon proposed by Zeonic was initially greeted with astonishment by high-ranking officials, including the Zabi family. The main point of development was focused on the power supply and its placement balance related to maintaining a certain operation time and movement independently, and auxiliary machine design for smoother operation of the limbs (manipulator). . As an aircraft with an almost humanoid appearance, the basic form was completed in the third generation prototype MS-03, but the strength of the aircraft to be used as a weapon (combat equipment with a view to melee combat was the first attempt in history). ), and high-precision manipulators that can handle various precision work were also required. We decided to let the MS handle the disassembly and assembly of heavy artillery as well as the ability as a heavy machine like a human being. This was because after deploying a surprise attack operation, it was necessary to quickly carry out work such as building a base and secure a logistics line. What was required of this mobile suit was not only a weapon, but also an aspect of heavy construction equipment.
After the MS-04 prototype was developed in UC0074, the armored mobile infantry MS-05, commonly known as Zaku (there is a theory that the commonly known name is an abbreviation for Zeon Air Command). However, when this aircraft was officially adopted, the EMS-04 Zuda by the competing manufacturer Tsimat was submitted to the competition as a competing machine (the first symbol E of the machine number has already been given to Zeonic's prototype development machine. Therefore, it is an abbreviation for special = extra). This is proof that the military had taken insurance over and over again in uncharted territory. This aircraft was a prototype with an ambitious design that focused on high mobility, but in terms of overall evaluation including productivity, Zeonic's Zaku was the winner (Zeonic's political power, which is close to the Zabi family) The suspicions about armaments from this perspective continued until the end of the war).
The Zaku, which is tailored to actual combat specifications, not only has a strong frame, but also has a monocoque outer shell armor that is more robust for close combat and hand-to-hand combat, and uses curved armor that takes into account the impact of bullets. there is In addition, the fluid pulse system for power transmission was all housed inside the armor to avoid damage during actual combat, but this rather led to more complicated maintenance, which is a big point for the next-generation 06 type. has been amended.
The year after the official adoption, the Zeon Guidance Mobile Battalion, which was established at the lunar base Granada, deployed 27 early production MS-05A Zakus, and trained the first mobile suit combat force. The armament used for the very early aircraft is a 105mm machine gun and a 280mm rocket bazooka. The following production model, the MS-05B, was equipped with shoulder armor as standard equipment for hand-to-hand combat, as well as a portable shield and a gas projectile launcher for colony suppression operations, all of which were MS-standard equipment.
Due to the thorough elimination of waste and the emphasis on versatility of work, the MS-05 was designed with no leeway to create a derivative model, but a total of 793 production type B types were manufactured. , Participated in the Principality of Zeon's initial operations with the next-generation 06 model. At the time of the formation of mixed units in the One Week War, the same gray-green camouflage paint as the 06 type was applied. In addition, the actual machine was continuously used by each unit until the end of the war (participated in the ground drop operation). When the following MS-06 became an official machine, the common name Zaku continued to be inherited, so this 05 type came to be distinguished as Zaku I thereafter.