Cobalt J-27 was a cobalt-rich asteroid located within the Roche asteroid field. The host of a Verpine-built and -maintained shipyard and repair facility, its use was leased by the Republic Navy in the years prior to the Great Sith War. By the first year of the Jedi Civil War it had fallen into the hands of the Sith Empire of Darths Revan and Malak, along with the rest of the Roche belt, and was quickly put to work repairing and upgrading their considerable naval strength.
In 3,958 BBY, in preparation for a Republic counterattack elsewhere, two squadrons of Aurek tactical strikefighters were sent on a mission to neutralize the asteroid's strategically-valuable support structures. The raid was intended to force the Sith into increasing their presence in the Roche system, hopefully drawing forces away from the true target of the Republic's main assault. The raid, conducted by the 23rd Marine and 52nd Starfighter Squadrons, was even more successful than anticipated. Not only was the asteroid put out of action indefinitely, but a damaged Interdictor-class cruiser and its six escorting Sith interceptors, as well as a medium transport and large, cargo-laden bulk freighter, were also eliminated.