Launched in Groton, CT in 1969, the nuclear powered NR-1, was one of the most secretive vessels in the U.S. undersea force. It was taken out of service in 2008 and disassembled. Now the Navy has collected pieces of it for an exhibit at a submarine museum in Groton, where it was based for the duration of its service life.

Primarily a research vessel, it also carried out a range of military missions that to this day remain top secret. Veterans who served aboard the tiny sub during the Cold War say that it was one of the most fascinating assignments of their careers — but that not even their wives know all the details.

Read more at http://www.military.com/daily-news/2013/11/13/submarine-its-sailors-maintain-cold-war-secrets.html.