South Korea conducts SLBM underwater ejection test from KSS-III-class submarine

South Korea has for the first time conducted underwater ejection tests of a locally developed submarine-launched ballistic missile (SLBM) from an in-service submarine, according to local media reports.

The Yonhap News Agency reported on 7 September that the SLBM tests, which were carried out the previous week by the Agency for Defense Development (ADD) from KSS-III-class submarine Dosan An Chang-ho (pennant number SS 083), follow similar tests conducted in recent months from an underwater barge.

The media outlet quoted unnamed military sources as saying that series-production of the SLBM, which has reportedly been codenamed ‘Hyeonmu 4-4' (also spelled ‘Hyunmoo 4-4'), will begin once a series of additional tests has been completed.

Yonhap also reported that the SLBM is believed to be a variant of South Korea's 500 km-range Hyeonmu-2B (also spelled Hyunmoo-2B) ballistic missile.

The Ministry of National Defense (MND) in Seoul declined to comment on the media report.

The Republic of Korea Navy (RoKN) commissioned Dosan An Chang-ho, its first locally developed, diesel-electric attack submarine capable of deploying SLBMs, during a ceremony held on 13 August at the facilities of Daewoo Shipbuilding and Marine Engineering (DSME) at Okpo on Geoje Island.

The boat, which is the RoKN's first of a planned fleet of nine KSS-III-class submarines, is expected to be operationally deployed from August 2022 after undergoing a series of operational performance and capability evaluations.

Equipped with locally made lead-acid batteries and an air-independent propulsion (AIP) system featuring hydrogen fuel cells, Dosan An Chang-ho