The Xelburok Worldship was an ancient alien spaceship, in which its derelict ruins were found in Deep Space -closest to the Nausica Sector- at the 3383 a.a.H by the Deep Space Miner Refinery Ship of the CONMI C.S.F Iwamura.
The Xel'Burok Worldship, designed as a giant ring that could encircle a whole planet, and as later investigations showed that it was a ship designed for terraforming planets, being a world-builder -and the author of the Aiers-type Planets.-
Estimates of the age of the ship varied between 300.000 to 220.000 years old, being discussed.
The discovery of the ship, while it was to remain a secret kept by the CONMI -some said, hoping to either to investigate the ship themselves, or to mine the derelict spaceship for its minerals-, the captain of the C.S.F Iwamura contacted the EUN, and soon afterwards the discovery became known among the secret services of the Capital human nations of the Nebulosa of Ots.
Soon, scientific teams were sent, and as began to be grasped the possible importance of this Worldship discovery, nations couldn't reach an agreement, and tensions regarding the Worldship arose.
-this will lead to the Space Battle of Nausica at the 3384 a.a.H.-
As the Nutks of the EAN were victorious, they seized the ship and began to investigate it, unveiling much of the secrets of the past of the Nebulosa of Ots, and acquiring much knowledge and technologies that were salvaged.
While doing this -and to try to deny its use to other powers-, the EAN began to dismantle the ship, until finally destroying it at the early stages of the Fifty Years War, to avoid it falling into RFB hands.