Zapadnaya Litsa
K-21 was laid down on 2 April 1960 and launched on 18 June 1961. K-21 entered service with the Northern Fleet (given to 3rd division of nuclear submarines which was a part of 1st submarine flotilla, based in Malaya Lopatka of Zapadnaya Litsa Fjord) on 28 November 1961. The submarine performed an Arctic cruise that year (passed 2,382 miles up-top and 3,524 miles submerged) and launched four torpedoes to determine a size of an ice-hole after explosion and a possibility to surface there.