Vellek's science ship was a Romulan science ship operated by the Romulan military during the 24th century.
Around 2391, the ship had Doctor Vellek aboard when it sustained critical damage. Fearing that his knowledge regarding an ancient Progenitor technology of immense power would be lost, Vellek transmitted a distress call with a clue to a map that he had planted, containing the technology's location.
In 3191, a Starfleet probe discovered the wreck of Vellek's ship orbiting a planet at the edge of the Beta Quadrant. The USS Discovery was dispatched on a Red Directive mission to retrieve Vellek's data, but upon arrival found that couriers Moll and L'ak had already taken it. (DIS: "Red Directive")
The interior sets for Vellek's ship were a re-use of the Discovery hallway and science lab sets.