USS Enterprise, USS Long Beach, center, and USS Bainbridge off of Mallorca during Operation Sea Orbit on July 31, 1964.Keystone/Getty Images On July 31, 1964, three US Navy ships set off on a mission to sail around the world. The ships were all nuclear-powered and composed the first task force of its kind in history. Their goal was to show the US's mastery of nuclear propulsion and the value of a nuclear fleet.