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Revolutionizing naval capability
Meet a first-of-its-kind unmanned ship
The No Manning Required Ship (NOMARS) program has built an unmanned surface vessel (USV) designed from the ground up to never accommodate a human aboard, the USX-1 Defiant.
By removing the human element from all ship design considerations, the program intends to demonstrate significant advantages, to include: Size, cost, at-sea reliability, greater hydrodynamic efficiency, survivability to sea-state, and survivability to adversary actions.
NOMARS is the kind of experimentation that could define a future hybrid maritime fleet, a manned-unmanned team with the ability to adapt and scale.
Bookmark this page to follow the journey as Defiant undergoes an extended at-sea demonstration of reliability and endurance, showcasing what’s possible when we rethink how we design, build, operate, and maintain ships.
Follow the Defiant
Aug. 5, 2025
Tackling both sides of the autonomy problem
NOMARS Program Manager Greg Avicola talks about the opportunities and challenges embraced in creating a first-of-its-kind ship. Source: DARPA | Tom Shortridge
Greg Avicola, NOMARS program manager, shares the importance of platform design in achieving successful autonomous systems. Designing a ship from the ground-up without any provision for people makes it possible to optimize the platform for autonomous operation.
But without people onboard to maintain systems, ensuring reliability in the harsh maritime environment becomes the new hardest problem.
July 18, 2025
Coming soon to an ocean near you
Sneak peak: The USX-1 Defiant moving under its own power and the NOMARS team is continuing in-water testing to prepare the ship for an extended at-sea demonstration of reliability and endurance. Source: DARPA | Spencer Bruttig
On the water in Puget Sound, Wash.
March 3, 2025
Defiant is in the water!
Construction is complete of the USX-1 Defiant, the demonstrator vessel for the NOMARS program. The 180-foot-long, 240-metric-ton lightship is in the waters of Puget Sound, Wash., where it will undergo in-water testing of all its component systems and integration.
The NOMARS program aims to challenge the traditional naval architecture model, designing a seaframe (the ship without mission systems) from the ground up with no provision, allowance, or expectation for humans on board. By removing the human element from all ship design considerations, the program intends to demonstrate significant advantages, to include: Size, cost, at-sea reliability, greater hydrodynamic efficiency, survivability to sea-state, and survivability to adversary actions through stealth considerations and tampering resistance.
With scaled production, NOMARS has the potential to efficiently and cost-effectively deliver a distributed USV fleet.
Dec. 19, 2024
Automated fueling-at-sea test completed
Fueling at sea (FAS) for USVs presents a problem that needs to be solved as current FAS solutions use personnel to handle lines and hoses on the platform being refueled. The NOMARS FAS approach is designed for operation without any human on the USV – but does have humans on the refueling vessel.
The FAS approach mirrors a standard refueling concept of operations (CONOPs) as closely as possible to be familiar to Military Sealift Command (MSC) oiler crew and reduce their learning curve.
For the recent test, USV Ranger carried a receiving station representative of the system that will be on the NOMARS USV Defiant, and USV Mariner carried a refueling “mini-station,” custom-designed by NOMARS prime contractor Serco Inc. | Learn more
