Prior to the design of the Millennium-class, Miratian close-air support relied on a network of militarized cargo vessels as improvised staging areas. They were ill-suited to holding, maintaining, refueling, or even launching any sort of helicopter, but were justified as "better than nothing." During the Sabikan Crisis, Greyhelm soldiers under the command of Master Sgt. Zakhar Kasabian were left without close-air support for the duration of their mission, in spite of the uncharacteristically rapid deployment of a flight of Tornados to the nearest avaliable ship. It was only due to the small size of their force that they were able to avoid direct engagement with the enemy until the opportunity arose to engage the weakened survivors of the initial rebel assault.
The post-operational analysis determined that the success of the mission was, to say the least, "improbable." The panel recommended that a new vessel be constructed with the express purpose of ferrying close air support rapidly around the continent of Frequesue as needed. The proposal called for a ship that could carry no fewer than a full squadron of twenty four helicopters and three hundred soldiers, plus ammunition and fuel for at least two sorties, and supplies to complete at least one full circumnavigation of the Continent before requiring resupply.
The North Frequesuan Trust agreed to engage in a joint project to produce the craft, which was then dubbed the Millennium-class. Development was completed in 2014. Whilst the Millennium-class was originally conceived as a conventionally powered ship the NFN operates a variant powered by a compact nuclear reactor design. This variant is frequently referred to as the Adventure-subclass, although it is not officially labelled as such. NFS Adventure and NFS Farbanti's Fortune are also armed with Mistral NG anti-air missiles rather than the Mirakarm-produced SAM-9 launcher, and forego the gun turret in favor of a small pack of VLS-mounted S-500 missiles.
- MAS Millennium, under construction
- NFS Adventure, commissioned and in service
- NFS Farbanti's Fortune, under construction