The Hoshikaze 2250 universe splits from our own timeline in the early '80s. During the last years of the 20th century, mankind pushed on to space. In 2023, warp drive was discovered, allowing for far greater acceleration than plasma drives. During the 2000-2020 years, researches were conducted aboard the LEO Alpha station, about links between quantic and relativistic physics. They revealed a previously unthought-of means of distorting space-time, that could possibly be used for propelling a spacecraft. But these programs were quite costly and, with the plasma drives being so successful and the crisis hitting the countries earthside, it was suspended, Only one company never let go, Kreuzer Gravitonics from Iserlohn, in the European State of Germany. After having escaped bankrupcy several times thanks to some successsful applied research patents, the company finally managed to recruit Nacera Ergozan and Matthew Reiley, two of the most successful physicists of their time, who entertained a decades-long rivalry and never before agreed to work together. Anna-Maria Kreuzer herself had to take a fierce fight to gain their cooperation. She was, however, quickly rewarded as the very first test of the Ergozan-Reiley warp drive was successfully conducted on March, 23rd, 2021. Only months later, Kreuzer officially announced the first operationnal warp-driven spacecraft. It boasted a far superior energy-to-thrust conversion ratio than plasma-driven ships and moreover, being reactionless, didn't need to carry a great mass of propellant to eject. Kreuzer Gravitonics announced at the same time the founding of Kreuzer RaumZeitKrümmungRaketen subsidiary to manage the licencing of their drive patent. The chinese Fengzi State Concern, builder of the well-known Haifeng and Weifeng cargo ships, didn't wait long to contact Kreuzer. They appointed Malcolm & Sons Shipbuilding, one of their longtime licensees, that built Haifeng and Weifeng ships from its LEO facility. The joint-venture, now known as Kreuzer-Malcolm, designed and built the first Iserlohn prototype in less than 3 months, thanks to the modular Weifeng base design and to the compatibility of warp drives with energy sources already used on plasma ships. The prototype was given the name of the birthplace and residence of Anna-Maria Kreuzer, where the earthside headquarters of all Kreuzer companies were located. As its maiden voyage to Mars and Jupiter in half the time needed with a regular Weifeng ship was heavily publicized, the name stuck at once and the class itself, which would otherwise have been named Hongfeng (Grand wind), became widely known as Iserlohn. Fengzi didn't object and officially endorsed the designation. From that time on, plasma ships began to be phased out and refitted to warp. The Weifeng were of course the first ones to be concerned, being routinely refitted at their standard 5-years ovehaul. These were dubbed Iserlohn Mk II to tell them from the newly built ships, which received the Mk I designation. Kreuzer RaumZeitKrümmungRaketen entered in a number of partnerships with ship designer concerns and notably with Zvezda Inc from Russia, the designers of the Utrennyaya Zvezda, one of the few concurrents of the Weifeng, whose warp derivative also received a german name, being known as Leiseläufer. The Iserlohn is structurally similar to the Weifeng. The only visible modification is the replacement of the plasma clusters at each end of the ship by warp engines. The elimination of the plasma plumes threat on the cargo modules allowed for shorter drive-support fins and a lower overall mass. Several modifications were made to the internal systems, like the refit of energy conduits from reactor to engines and the reduction of propellant conduits, now only used for vernier operation. It was initially proposed to downsize the hydrogen tanks, but this was ruled out in favor of gaining in endurance, even on continuous acceleration courses. (model and image made under DoGA L3, then inserted into PowerPoint slide)