Hyliion Holdings’ KARNO power generation system will undergo sea trials aboard the unmanned surface vessel USX-1 Defiant under DARPA.
Hyliion Holdings’ KARNO power generation system will undergo sea trials aboard the USX-1 Defiant, an unmanned surface vessel developed under DARPA's No Manning Required Ship (NOMARS) program.
Hyliion will supply an 800-kilowatt system made up of four 200-kilowatt KARNO Core units configured for marine operation.
The modular arrangement is designed to maintain power generation if individual units fail, a feature considered important for unmanned vessels where onboard maintenance is unavailable.
The KARNO Core is a linear generator that converts heat into electricity and can run on multiple fuel types.
For the naval trials it will use F-76 marine diesel, the standard fuel across much of the US surface fleet. The units produce 800-volt direct current, compatible with modern shipboard electrical systems.
Land-based testing using simulated US Navy load profiles is already underway ahead of the sea trials.
USX-1 Defiant
The USX-1 Defiant was developed by Serco North America under DARPA's NOMARS program, which is designing naval vessels intended to operate entirely without crew.
The platform, which measures about 180 feet (55 meters) in length and displaces roughly 240 metric tons, was built without crew accommodations, allowing designers to prioritize endurance, automation, and reduced maintenance.
It serves as a technology demonstrator for long-duration autonomous missions.
The sea trials are funded through the Office of Naval Research. Neither ONR nor DARPA provided a timeline for the trials or any potential follow-on program.
