For other uses of the name Copernicus
The USS Copernicus is a sleeper ship used by humans for deep space travel before jumpgates were provided by the Centauri in 2161. Chartered by a private corporation to look for alien life, the Copernicus carried cryonic freezer technology to preserve its crew, Mariah Cirrus and her husband William Cirrus, for the ship's long journey. The ship had thrusters.
Just after the Earth-Minbari War, the Copernicus drifted near a lifeless moon, where a Soldier of Darkness boarded the vessel and reprogrammed the Copernicus's flight path to take it to Z'ha'dum, intending to use the two crew members as sustenance for the duration. In 2259, the Copernicus drifted into the Epsilon Eridani system and came within range of Babylon 5. The Copernicus homed in on the station's signals, transmitted its automated greeting, and was brought aboard the station, carrying with it the still-living Mariah and the Soldier of Darkness.