In promoting the Gundam development plan, the Earth Federation Forces have long been paying attention to the existence of the mobile armor that the Principality of Zeon forces introduced in each tactical response during the One Year War. Mobile suits were active as armored mobile weapons to replace conventional fighters, but in large-scale battles including fleet battles, the use of naval guns would not be excessive. As a heavy attack aircraft with defensive weapons, various single attack aircraft in the category called mobile armor were developed as heavy armored mobile weapons that have more striking power than cruisers and can be used in combination with mobile suit units to open the battlefield. . Each prototype, which was developed with an emphasis on specific functions without giving versatility to changes in the battle situation, succeeded in achieving a better-than-expected battle record. The Earth Federation Forces, who could not even imagine a heavy artillery vessel with the mobility of a mobile suit, could never erase the memory of this fantasy weapon. Therefore, in this Gundam development plan, in addition to general-purpose attack mobile suits and heavy assault mobile suits, it was proposed to add heavy mobile armor to the draft. In this respect as well, it is possible to measure the magnitude of the expectations placed on Anaheim Electronics by the leadership of the Federation Forces. Furthermore, since it is a mobile armor specialized for operation in outer space, a design proposal was finally passed to use a Gundam-type mobile suit for space battles as the central part responsible for its control system. In other words, the concept is that the Gundam machine is the second shell for the core block, which is an escape and recovery system, and the machine that houses the Gundam is the third shell. It was intended to improve the pilot's survival rate and high mobility when confronting a large number of mobile suits, which are the drawbacks of mobile armor. This is an idea that leads to the composite hull design of the large attack aircraft FA-78-400, which was considered as a base attack aircraft plan in the FSWS concept at the end of the war and became a thought-guided weapon carrier. The mobile suit unit, which also serves as the control center section, was designed and developed as the RX-78GP03S Gundam Steimen, and the large armed base and high-output mobile propulsion unit was named Orchis, and development proceeded in parallel. Since the Steimen does not require ground-based practical testing, extremely rapid manufacturing development takes place at our Anaheim headquarters. Since the mobile suit unit itself is designed to be separable from the mobile armor unit, and because it is necessary to centralize the system control as the overall control center in mobile armor mode, the Core Fighter II's escape and recovery system is omitted in this stay. , Instead, it has been changed to a spherical cockpit module equipped with an all-sky monitor (at the rollout stage, the core block system was incorporated into the airframe design and completed). Since this RX-78GP03S staymen is operated in mobile armor mode, a tail stabilizer that doubles as a docking Form has been added to the waist. This also serves as a high-mobility thruster when used in MS-only mode. In addition, the Stamen's arm contains a large deployable manipulator, specially designed to allow weapons to be taken out of Orchis's weapon container. On the other hand, the Earth Federation Forces' first mobile armor outer shell Orchis was designed by a design team transferred from MIP, which was engaged in mobile armor development for the former Principality of Zeon. Anaheim also focused on inviting such experienced personnel. The design of the Orchis is roughly divided into three parts. In addition to the main gun (Mega Beam Cannon) laid out on the starboard side of the main frame that connects to the mobile suit unit, the federation The military's first I-field generator was installed as defensive armament. In addition, the central part that comprehensively protects the mobile suit unit has an outer shell armor, and the underside of the fuselage has a large manipulator equivalent to the "arm" as a mobile armor built into the frame. The latter half of the fuselage is made up of thruster units that boast propulsion power comparable to that of large warships, and high-mobility sub-engines that can withstand that mass are also laid out in various places. The third component is the composite armed container unit. The amount of firearms possessed by this Orchis, including the micro-missiles housed in each tank of the system container, reached the load of a destroyer class when sortied with all equipment. In addition, in the storage space provided in each of the left and right containers, in addition to the micro missile container, it is possible to select focused anti-ship missiles (three units are stored in one container tray), and the full loading system container can be reloaded. By fixing it, it was possible to continue the attack time. However, due to the size of the aircraft, such replenishment work could only be done outside the mothership, and it cannot be denied that there were operational problems. A mobile suit unit connected to this Orchis is called the RX-78GP03 Dendrobium, and direct attacks are possible with the claw arms stored in the starboard and starboard pods on the underside of the fuselage. A beam saber is built into the tip of this claw arm, and in addition to utilizing the empirical rule of effective use of the AMBAC system such as MA-05 Bigro, MA-06 Val Valo, and MAM-07 Grabro, , It is also possible to operate in the single-machine battle phase, which expands the MS fighting battle. In addition, this container space can also accommodate the folding bazooka developed for this machine and the hyper bazooka, which is standard equipment for the Gundam type. With the Steimen's retractable and deployable folding arms, it was possible to use independent firearms even in the MS part of the control center. The practical test of this gigantic aircraft was carried out not at the Anaheim Electronics headquarters in Von Braun, but at the company's large mobile dock, La Vie en Rose. However, GP01Fb was lost in battle with GP02A following the Delaz Fleet's attack on the Earth Federation Forces using nuclear warheads. Received an order from Major Nakach Nakato, who is trying to bring things under control, to cancel the mission to pursue the Delaz Fleet. However, due to the judgment of Albion's captains, Colonel Aper Synapse and Nina Purpleton, the RX-78GP03, whose development plan will eventually be canceled, is continuing implementation tests at La Vie en Rose, so they plan to use the aircraft. In order to prevent Fleet's colony drop operation, he went against the instructions of the military general office and forced to use it without permission. However, the Delaz Fleet deployed the Mobile Armor AMA-002 Neue Ziel, which had been continuously developed for the Newtype provided by the Axis Fleet, to the escort fleet in the operation area under the control of Lieutenant Commander Annabelle Gato, Ensign Kou Uraki. As a result of fighting again with GP03, both were unable to fight, GP03 discarded the Orchis unit, and Neue Ziel followed the fate of exploding. This machine was completed as a base attack machine and a base defense machine with the highest and strongest equipment, but with the cancellation of the Gundam development plan, it is said that the design outline and various development data have all been deleted.