American submarine NR - 1 Deep Submergence Vessel " NR - 1 " was a unique United States Navy nuclear - powered ocean engineering and research submarine . Built by the Electric Boat Division of General Dynamics at Groton , Connecticut " NR - 1 " was launched on 25 January 1969 , completed initial sea trials 19 August 1969 , and was home - ported at Naval Submarine Base New London . Casually known as " Nerwin " , " NR - 1 " was never officially named or commissioned . The US Navy is allocated a specific number of warships by the US Congress . Admiral Hyman Rickover not only avoided using one of those allocations , but he also wanted to avoid the oversight that a warship receives from various bureaus . History . " NR - 1 ' s " missions included search , object recovery , geological survey , oceanographic research , and installation and maintenance of underwater equipment . " NR - 1 ' s " unique capability to remain at one site and completely map or search an area with a high degree of accuracy was a valuable asset on several occasions . Following the loss of the Space Shuttle " Challenger " in 1986 , " NR - 1 " was used to search for , identify , and recover critical parts of the " Challenger " craft . Because it could remain on the sea floor without resurfacing frequently , " NR - 1 " was a major tool for searching deep waters . " NR - 1 " remained submerged and on station even when heavy weather and rough seas hit the area and forced all other search and recovery ships into port . In 1995 , Dr . Robert Ballard used the " NR - 1 " and its support ship , , to explore the wreck of , the sister ship of , which sank off the coast of Greece while serving as a hospital ship during World War I . On 25 February 2007 , " NR - 1 " , towed by " Carolyn Chouest " , arrived in Galveston , Texas , in preparation for an expedition to survey the Flower Garden Banks National Marine Sanctuary and other sites in the Gulf of Mexico . " NR - 1 " was deactivated on 21 November 2008 at the US Navy submarine base at Groton , Connecticut , defuelled at Portsmouth Naval Shipyard in Kittery , Maine , then sent to Puget Sound Naval Shipyard to be scrapped . Capabilities . " NR - 1 " performed underwater search and recovery , oceanographic research missions and installation and maintenance of underwater equipment to a depth of almost half a nautical mile . Its features included extending bottoming wheels , three viewing ports , exterior lighting , television and still cameras for color photographic studies , an object recovery claw , a manipulator that could be fitted with various gripping and cutting tools and a work basket that could be used in conjunction with the manipulator to deposit or recover items in the sea . Surface vision was provided by a television periscope permanently installed on a fixed mast its her sail area . " NR - 1 " had sophisticated electronics , computers and sonar systems that aided in navigation , communications , and object location and identification . It could maneuver or hold a steady position on or close to the seabed or underwater ridges , detect and identify objects at a considerable distance , and lift objects off the ocean floor . " NR - 1 " was equipped with two electric - motor driven propellers and its maneuverability was enhanced by four ducted thrusters , two forward and two aft . The vehicle had diving planes mounted on the sail , and a conventional rudder . " NR - 1 " could travel submerged at approximately four knots for long periods , limited only by consumable supplies — primarily food . It could study and map the ocean bottom , including temperature , currents , and other information for military , commercial and scientific uses . Its nuclear propulsion provided independence from surface support ships and essentially unlimited endurance . " NR - 1 " was generally towed to and from remote mission locations by an accompanying surface tender , which was also capable of conducting research in conjunction with the submarine . " NR - 1 ' s " last mother ship was MV " Carolyn Chouest " , which provided towing , communications , berthing and direct mission support for all " NR - 1 " operations . An extremely versatile platform , she was an indispensable member of the " NR - 1 " deep submergence team . " NR - 1 " command was manned with thirty - five Navy personnel and ten civilian contractor personnel . " NR - 1 " carried as many as thirteen persons ( crew and specialists ) at one time , including three of the four assigned officers . ( The operations officer rode on " Carolyn Chouest " ) . All personnel that crewed " NR - 1 " were nuclear - trained and specifically screened and interviewed by the Director , Navy Nuclear Propulsion Program .