The Strategic Defence Review issued in February 2003, considered the S-80 Submarine a priority programme. This document takes into account the need to procure submarine units to maintain the freedom of action and mobility of the Force with two submarines operating simultaneously in two theatres: one in a far away scenario and another close by. The units will have an air independent propulsion system with land-attack missile capability and important elements for intelligence gathering.
Preliminary studies were carried out between 1989 and 1991. In the year 1997 the programme started following the PAPS method. (Phased Armaments Programming System):
Changes in the world strategic situation recommended a review of operational requirements to adapt the submarine to new scenarios and demands. New “Staff Requirements” were approved by the Spanish Chief of Naval Staff in July 2002.
The main changes included the air independent propulsion system (AIP) and land-attack capability.
In March 2004 the Shipbuilding Order was signed between the Ministry of Defence/Spanish Navy and IZAR to build four S-80 Submarines. The main milestones are: