The upgraded version, the Sierra II class was specifically developed for search and destroy missions against US nuclear submarines.

[2] The first submarine of the Project 945, Carp, was laid down in July 1979[3] at the Gorky shipyard and was launched in August 1983 before being transferred to Severodvinsk for fitting out.

K-276 Kostroma was put into a drydock after its 11 February 1992 collision with the US submarine Baton Rouge in the Barents Sea, off Kildin Island.

[citation needed] Of the two existing submarines of type Sierra II, the Pskov was in overhaul between 2011 and 2015 according to the Russian website Deep storm.

Zvezdochka was to carry out the refit, repair mechanical parts, and replace nuclear fuel and all electrical equipment of the submarines.

[15] However, in March 2015 it was reported that the final decision on the modernization of submarines Carp and Kostroma had not yet been made due to cost issues.