The Navy's deepest-diving submarine, which conducted both research and covert military operations along the ocean floor during the Cold War is making its return to Connecticut.

According to The Associated Press, the NR-1, a nuclear-powered submarine that was commissioned in 1969, will be on display at the U.S. Navy Submarine Force Library and Museum in Groton, Conn. Having been disassembled in 2008, the museum will only display the sub's restored pieces. 

At 140-feet long, the news source stated that the NR-1 was a powerful underwater vessel unmatched in the Navy. While carrying a crew of 10 men, the sub was able to dive to 3,000 feet below sea level, where it could grab items from the ocean floor with a mechanical claw. 

While some of the submarine's missions are known to the public, including its task of retrieving particles from the space shuttle Challenger after it exploded over the Atlantic, the news source reported that much of its military operations still remain classified. According to the source, mission records could not be traced by the Navy's History and Heritage Command in Washington, D.C., and even veterans are remaining quiet about their past experiences until the files are declassified.

Also on display at Groton's submarine museum is the historic USS Nautilus, the first operational nuclear-powered submarine in the world, as well as the first vessel to travel to the North Pole, according to the museum's website.