The Antares-class freighter was a type of starship operated by civilians for the United Federation of Planets and other organizations. Ships of the class were protected by standard deflector shields and could support crews of at least twelve. The Antares-class was capable of hauling a variety of freight, including deuridium, duridium and dilithium. In addition, crews could also haul various types of supplies and material stipulated by contract. (DS9: "The Passenger", "The Adversary", "For the Cause"; VOY: "Author, Author")
Ships of the Class
- VOY: "Author, Author"
The Antares -class designation as established for the SS Xhosa, was, according to Mike Okuda, meant as a homage to the Antares (NCC-501), referenced to in the The Original Series episode "Charlie X", further elaborated upon in all the interior details, the TOS style consoles and the SS Xhosa dedication plaque. 
The Xhosa was one of the few starships that did not feature a captain's chair on the bridge; instead, there was a central console in front of the viewscreen manned by the captain and the engineer of the ship. The Norkova bridge set was later on redressed as the Nebula-class USS Prometheus bridge for the season 2 episode "Second Sight".
The studio model for the Norkova was one of many modifications that originally started as the Talarian freighter Batris from TNG: "Heart of Glory", and included a redesigned bow section. The model was later repainted and reused as the Xhosa in "The Way of the Warrior." The Talarian freighter was first identified in the Star Trek Encyclopedia as an Antares-class ship, the Xhosa was identified as such canonically in her dedication plaque, suggesting both designs might be variants of the same class. For further information on the studio model, see Batris model.
Although not explicitly stated as a Federation vessel, the impression was given that it was. What remains unclear is the possibility of whether or not the Norkova was under a Federation registry, or if it was registered as an independent, "third party" vessel. The existing doubt is based by later established fact that not all Human-run vessels, like the Norkova, were under Federation registry – as was the case with the Xhosa, which was commanded by Human captain Kasidy Yates and constructed at the Luna Shipyards, was under a Petarian registry. This type of vessel also appeared approaching a Federation dilithium mining colony in VOY: "Author, Author", again implying this type of vessel was connected to the Federation.