The USS Tunguska was a Federation runabout assigned by Starfleet to the Tezwa rebuilding effort. The Tunguska was assigned to travel to Anara-Zel to capture contraband cargo shipments from the Tezwans; later, it was headed for the Alkam-Zar communications center, but was struck by anti-aircraft weapon. The blast killed most aboard except for Scott Fillion and Fiona McEwan, who survived the crash landing but were later killed by insurgent forces on the surface. (TNG novel: A Time to Heal)

Although the vessel's class wasn't specified, given the series and time period it was likely a Danube-class. Although never mentioned as such in the novel, the USS prefix is also speculation.