(coexisting on another dimensional plane)
This page contains information regarding I AM ERROR, and thus may contain spoilers.
The ship was launched from the Tranquility Base shipyard. Its motto was the Latin translation of the USS Discovery's motto: "Facile intelligere semel invento sunt omnio quoe vero sund, sed quoe sunt difficilis quoestio est deprehendere."
In late 2256, the vessel was under the command of Captain Sylvia Tilly, who rose to the position after killing the previous captain. The same year, it was theorized by the crew of the USS Discovery that the vessel had crossed into their universe by the same spore drive malfunction that had stranded the USS Discovery in this universe. As a result, Captain Lorca ordered his crew to modify all of the ship's systems and visual outlook to emulate the ISS Discovery.
The USS and ISS Discovery were almost identical in outward configuration, and had the same registry (NCC-1031) and class. However, the ISS Discovery had several details that its counterpart lacked, such as the dagger emblem of the Empire painted on the doors, agony booths to keep the crew in line, armed soldiers in the corridors, and agonizers. (DIS: "Despite Yourself")