The CSS Xeno was an ocean-going vessel operated by the Combined Services of United Earth in the 21st century. In late 2045, Melody Sawyer was given command of the Xeno, and remained her captain for twenty years. In 2065, the Xeno was critically damaged by an engine room explosion. Sawyer got all hands off ship, but perished herself as the ship sank. (TOS novel: Strangers from the Sky)