Contract to build the first airship capable of exploring all of Ekkirah

When Nasuha "Explorer of the Skies" returned from the maiden voyage of the Sogno, he was greeted with praise. News of this event spread all across the islands, and even reaching far neighbouring regions. The sky was no longer the limit, it has been tamed by the greatest scholar this nation had ever seen, including any previous to The Ascent. With this achievement attached to his name, nobility, royalty and all other scholars flocked to him, but one contract that was offered stood out. Amonst all contracts to build tradeships, warships or any other designs, the scholars wanted him to build an exploration ship, capable of traveling across all of Ekkirah. The document reads as follows:
Dear Nasuha Morphus,
with great exitement we witnesses the maiden flight of the first airship ever built.
The council of scholars hereby offers you a contract to build a vessel capable of traveling to the far reaches of Ekkirah. In order to achieve this task, these are the requirements we need you to meet.
The Airship must be capable of flying by the use of an engine that could be refueled and not by magic users constantly feeding it their mana. The Airship must be capable of carrying around 150 crewmembers. The Airship must be capable of withstanding any weather condition it might come across. The Airship must be capable of defending itself if absolutely necessary. The Airship must be capable of being repaired along the journey.
The whole project has no deadline, but a limit on how much the construction would cost.
With these set rules in place, Nasuha started working. Researching materials that were capable of emitting magical energy so that they would work as fuel. The materials also had to be almost readily available all over the world, as rare materials might make refueling or repair almost impossible.