The Cold War produced renewed Soviet interest in the islands because of their strategic military significance. The islands were regarded as an "unsinkable aircraft carrier". The site of the former German weather station was selected as the location of a Soviet aerodrome and military base, Nagurskoye. With the advent of intercontinental ballistic missiles, the Soviet Union changed its military strategy in 1956, abolishing the strategic need for an airbase on the archipelago. The International Geophysical Year of 1957 and 1958 gave a new rise to the scientific interest in the archipelago and an airstrip was built on Heiss Island in 1956. The following year the geophysical Ernst Krenkel Observatory was established there. Activity at Tikhaya Bay was closed in 1959.