The Heisenberg was a warp-capable ship owned and operated by the Cochrane Institute of Alpha Centauri in the mid-22nd century, commanded by Captain Monsees. It was to be used as the testbed for the first prototype transporter, when it was seized by Romulans. The Heisenberg's drive section was destroyed in the successful effort to repel these captors, presumably leaving the remainder of the vessel unsalvagable. (DS9 - The Lives of Dax short story: "Dead Man's Hand")