Pentagon unveils robo-warship that operates with no crew

By Dean Murray

A mysterious U.S. robo-warship able to spend months at sea without humans has been unveiled.

The USX-1 Defiant was officially launched this week by DARPA, the research and development agency of the United States Department of Defense.

The No Manning Required Ship (NOMARS) program has built a vessel designed to operate autonomously for long durations.

While DARPA has been working on the NOMARS program since 2020, details about the specific vessel were limited until its recent appearance.

A sighting of the Defiant being towed through Saratoga Passage in Puget Sound near Seattle sparked initial public interest and speculation.

On Tuesday (4 Mar), DARPA confirmed that construction of the prototype unmanned surface vessel (USV) was completed in February 2025, adding "USX-1 Defiant has officially launched."

They said: "Defiant is a 180’, 240-metric-ton lightship that will undergo extensive in-water testing, both dockside and at sea. She is scheduled to depart for a multi-month at-sea demonstration in spring 2025."

The NOMARS program aims to challenge the traditional naval architecture model, by designing a sea frame (the ship without mission systems) from the ground up with no provision, allowance, or expectation for humans on board.

DARPA said: "By removing the human element from all ship design considerations, the program intends to demonstrate significant advantages, including: size, cost, at-sea reliability, greater hydrodynamic efficiency, survivability to sea-state, and survivability to adversary actions through stealth considerations and tampering resistance."

Department of Defense could now scale production of NOMARS to efficiently and cost-effectively deliver a distributed USV fleet.