The Epsilon-class was a Federation cutter starship in Starfleet service in the 23rd century, with a class III mark I version that became active on reference stardate 2/1104, and a class IV mark II upgrade to the design which entered service on stardate 2/1412. The vessel's name derives from the Greek language letter epsilon, and is a name shared by the Epsilon sector and Epsilon system within Federation space. Presumably, there would have been a USS Epsilon that was the prototype of this series, but no mention has been made of such a vessel.