Key Points and Summary – The U.S. Navy’s Office of Naval Research has posted a Request for Proposals for the Ocean Explorer (OEX), a new “ultra-large” autonomous submarine designed for long-endurance, ocean-scale missions with a large modular payload.
-This initiative follows the successful in-water testing of DARPA’s Manta Ray prototype, which validated concepts for large, modular unmanned undersea vehicles (UUVs).
-The OEX program is part of a broader push by the Navy to develop a “hybrid fleet,” which also includes the Large Displacement UUV (LDUUV) and Boeing’s Orca Extra Large UUV (XLUUV), to extend naval reach and reduce operational risk.
A ‘Hybrid Fleet’: Inside the Navy’s Push for Giant Robot Submarines
The United States Navy has posted a Request for Proposals (RFP) for the development of an Ocean Explorer (OEX) large underwater vehicle capable of long-endurance operations. The Office of Naval Research (ONR) revealed the project. It is the most high-profile example to date of the US Navy accelerating its investment in autonomous undersea warfare platforms.
This US Navy solicitation is for what it called the Ocean Explorer (OEX) Large Unmanned Underwater Vehicle (LUUV). This vehicle is proposed to be an ultra-large, unmanned submarine designed for ocean-scale, long-endurance missions.
According to the ONR requirement, the OEX program office is seeking industry proposals for an advanced autonomous system capable of transporting substantial modular payloads over extended operational ranges. Based on the performance objectives in the ONR’s announcement, the OEX will be a next-generation autonomous platform with a persistent presence on-station and modular flexibility at its core.
Previous UUV Projects
A prior effort leading up to this ONR program came from the Defense Advanced Research Projects Agency (DARPA). The agency had previously designed and progressed through the Manta Ray program, a project aimed at validating the concept for a new class of ultra-endurance UUVs.
Northrop Grumman’s Manta Ray prototype completed in-water testing off the coast of Southern California in early 2024. The vehicle demonstrated hydrodynamic maneuverability and operational readiness after modular in-field assembly. This program demonstrated what experts call “a critical step in expeditionary logistics for autonomous systems.”
DARPA’s program manager, Dr. Kyle Woerner, stated, “The combination of cross-country modular transportation, in-field assembly, and subsequent deployment demonstrates a first-of-kind capability for an extra-large UUV.”
ONR Requirements
ONR states that any tenders should include a full-cost plan for the preliminary design phase, a detailed design option, and a rapid prototype design and fabrication pathway for the production of the OEX.
Submissions will be screened to establish the technical feasibility of the submarine drone and related performance with a payload module. Additional metrics will focus on the groundwork for operational and maintenance infrastructure required to support a potential OEX squadron.
The program will be structured to evaluate both the technical feasibility of the submarine drone and its performance with various mission-configurable payload modules. One of the significant performance points to be assessed in the solicitation process will be the contractors’ potential to not only design and build the vehicle but also establish logistics, sustainment, and support infrastructure for potential squadron-level deployments of OEX units.
Proposals must also demonstrate how the vehicle can integrate into future naval operations, especially in distributed maritime environments. White paper submissions are due by July 2025, with full proposals expected by October 2025.
Additional US Navy UUV Projects
The OEX initiative is one of several undersea autonomy programs currently underway in the United States. These systems will extend naval reach, reduce operational risk to manned assets, and enhance distributed maritime operations across contested theaters such as the Indo-Pacific.
The US Navy’s OEX project is being conducted in parallel with the Large Displacement Unmanned Underwater Vehicle (LDUUV) initiative, which aims to deliver long-endurance and deep-water autonomous assets that can distribute key solutions, such as sensing payloads and effectors, across fleets in the Pacific and other austere theaters.
Among the LDUUV’s industry partners are Kongsberg, Anduril, and Oceaneering International—firms known not only for expertise in maritime operations but also for the design and development of unmanned systems.
The Navy is also working on the Extra Large Unmanned Undersea Vehicle (XLUUV) framework, a new class of autonomous submarines featuring diesel-electric hybrid propulsion and a payload section designed for various classes of operations.
The XLUUV project, led by Boeing, will be designated as the Orca-class fleet once it is commissioned into service. The Orca extra-large unmanned undersea vehicle’s design is based on Boeing’s Echo Voyager unmanned diesel-electric submersible.
About the Author:
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is an Expert on Foreign Military Affairs and Director of the Asian Research Centre with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
More Fighters
China’s J-20 Stealth Fighter Looks Like a Powerhouse
China’s White Emperor Space Fighter Looks Fake
China’s Aircraft Carriers Have Arrived (Just Not Nuclear Carriers)
