A 32nd-century Starfleet ship that is one of the vessels joining the USS Athena at the planet Faan Alpha for the staged battle with the Klingons in the Starfleet Academy episode Vox in Excelso.
The USS Capricorn is a Starfleet ship of the 32nd century seen in the first-season Star Trek: Starfleet Academy episode Vox in Excelso. It is one of a group of Federation ships, with others such as the Horizon, the Lexington and the Riker, that gather with the USS Athena at Faan Alpha.
The planet has been chosen as a new home for Klingon refugees, but General Wochak will not take it as a gift. Following an idea from the Klingon cadet Jay-Den Kraag, Nahla Ake and Admiral Vance declare the Klingon ships in the sector to be enemies and offer battle.
The fight is a matter of form. Both sides take care to miss or to do only slight damage, Vance surrenders, and the Klingons claim Faan Alpha as the prize of victory with their honour intact. Nothing more has been established about the Capricorn or its crew.