No sailors in sight: DARPA launches warship designed ‘from the ground up’ to be truly unmanned
Produced by SERCO through the research agency’s NOMARS program, the ship has been named Defiant (USX-1).
DARPA’s NOMARS is a 180-footlong warship designed from the ground up to not have humans aboard. (Photo courtesy of DARPA)
WASHINGTON — A key Pentagon research and development agency said it has successfully launched and will soon begin sea trials for a vessel dubbed “NOMARS,” a warship built from the ground up to sail without any humans aboard.
“The No Manning Required Ship (NOMARS) program has built a ship designed to operate autonomously for long durations at sea,” according to a statement from the Defense Advanced Research Projects Agency on Tuesday. “Construction of the prototype, unmanned surface vessel (USV) was completed in February 2025.”
Sea trials for the ship, dubbed Defiant (USX-1) and which does not have any mission or combat systems installed onboard, are scheduled for spring 2025, the statement added.
DARPA in August 2022 selected tech and engineering firm SERCO to design and build NOMARS, a USV measuring 180 feet long and weighing 240 metric tons. While the Pentagon’s interest in unmanned surface vessels is well documented — and industry’s supply of options is vast — NOMARS aims to fulfill a somewhat surprising gap given the technology’s name: An operational ship with no people aboard.
The majority of USVs the Pentagon uses are either small drones that could not physically carry a human (i.e. Saildrone) or they have been modified to operate autonomously but still have all the relevant spaces to sustain life (i.e. Mariner). The US Navy has taken to calling the ladder “optionally manned ships.”
Proponents of the technology argue that allowing for “optional manning” defeats the purpose of unmanned ships from the start. The spaces required for human life — bunks, food storage, bathrooms, life preservation equipment — are costly. Cue the NOMARS program.
“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,” according to DARPA. “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.”
Doing as much presents its own sets of challenges, but also a new world of potential solutions. For example, what happens if a fire breaks out aboard Defiant? The answer, Navy officials and others have previously told Breaking Defense, is that the ship can be equipped with a special gas that floods its internal spaces. That gas, which would have health repercussions if humans inhaled it, can deprive the compartment of oxygen, snuffing out a fire.
