From Halopedia, the Halo wiki
In the 2490s, the Colonial Administration Authority colony ship Chalybeate landed on one of the moon's mudflats for repairs. Instead of taking off again, the ship stayed grounded. Over the course of 60 years, hundreds of other ships began to rest around the Chalybeate turning this collection of vessels into the moon's capital city. This earned the moon its reputation of being the 'junkyard' of the Via Casilina Trade Route.
In the May of 2557, Rion Forge and Niko returned to the moon to have their ship, the Ace of Spades, repaired. By this time, the moon was considered to have the best shipyards in the Outer Colonies.
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