History of submarines few years before the US, and paralleled subsequent US development in this area. In the 1950s, nuclear power partially replaced diesel-electric propulsion. The sailing of the first nuclear-powered submarine, the USN ""Nautilus"" in 1955 was soon followed by similar British, French and Russian boats. Equipment was also developed to extract oxygen from sea water. These two innovations, together with inertial navigation systems, gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as the crossing of the North Pole beneath the Arctic ice cap by the USS "Nautilus" in 1958. Most of the
The City of Shifting Waters Galaxity in "Bad Dreams", has escaped captivity and fled into the Earth's past – the year 1986 – a time period agents have been forbidden to visit since the foundation of Galaxity. A nuclear explosion at the North Pole that year caused the polar ice cap to melt engulfing most of the Earth's cities. Valérian is ordered to pursue Xombul while Laureline is to remain at Galaxity until needed. Valérian arrives in 1986, in New York in the "Statue of Liberty" just as it collapses under a wave and Valérian is thrown into the Hudson. He is rescued by a