In an event designated Demonstration and Shakedown Operation-32 (DASO-32) an unarmed Trident II D5LE submarine-launched ballistic missile (SLBM) was launched from the US Navy Ohio-class nuclear-powered ballistic missile submarine USS Louisiana (SSBN 743) on 27 September 2023 off the coast of San Diego, California, the US Navy reported.

The conclusion of DASO-32, which demonstrated the readiness of USS Louisiana’s strategic weapon system and crew before operational deployment following the submarine’s engineered refuelling overhaul (ERO), was the last DASO to be conducted by an Ohio-class SSBN coming out of ERO and marks the completion of all post-ERO DASOs for the Ohio class.

In a 29 September press release Lockheed Martin, which is the prime contractor for building and upgrading the Trident missile, noted that DASO-32 increased the Trident II D5’s record to 191 successful test launches since its design was completed in 1989.

During DASO-32 data was collected in relation to the D5 Life Extension missile’s performance using a test missile kit also produced by Lockheed Martin.

As well as the US Navy’s Ohio-class SSBNs, the Trident D5 missile also arms the UK Royal Navy’s Vanguard-class SSBNs. It is also destined to arm the US Columbia-class and UK Dreadnought-class SSBNs when they enter service.

Billed as the most advanced SLBM in the world, the Trident D5 is a three-stage, solid-propellant, inertial-guided ballistic missile that can reach a nominal range of 4,000 n miles and carry multiple independently targeted re-entry vehicles armed with nuclear warheads.

An unarmed Trident II D5LE SLBM was launched from the US Navy Ohio-class SSBN USS Louisiana off the coast of San Diego, California, on 27 September 2023. The firing marked the last Demonstration and Shakedown Operation (DASO) to be conducted by an Ohio-class SSBN coming out of engineered refuelling overhaul (ERO) and marks the completion of all post-ERO DASOs for the Ohio class. (Photo: US Navy)