The USS Rio Grande (NCC-72452) was a Federation Danube-class runabout in service to Starfleet in the late 24th century. The Rio Grande was one of the first five Danube runabouts to enter service with Starfleet. (Ship Recognition Manual, Volume 1: The Ships of Starfleet) In 2369, it was assigned to Deep Space 9. Piloted by Commander Benjamin Sisko and Lieutenant [Jadzia Dax]] it discovered the Bajoran wormhole and made the first transit through it by a Federation vessel to the Gamma Quadrant. In doing so Sisko became the Emissary of the Prophets. (DS9: "Emissary")