According to the National Geographic, Bob Ballard’s discovery of the Titanic was tangential to the real Navy mission of investigating two wrecked nuclear submarines.

The Thresher and Scorpion had sunk in the North Atlantic Ocean at depths of between 10,000 and 15,000 feet (3,000 and 4,600 meters).

The military wanted to know the fate of the nuclear reactors that powered the ships, Ballard said.

This knowledge was to help determine the environmental safety of disposing of additional nuclear materials in the oceans.

The Navy also wanted to find out if there was any evidence to support the theory that the Scorpion had been shot down by the Soviets.