Defense Advanced Research Projects AgencyTagged Content List

Maritime Systems

Manned and unmanned surface and undersea systems, including vehicles, robotics and supporting technologies

Showing 5 results for Maritime + History RSS
On January 25, 2018, DARPA took its Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program to one of the best finish lines the Agency knows of—an official transfer of a technology to a follow-on steward of development or to an end user in the field. In this case, following a period of open-water tests of the program’s demonstration vessel—dubbed “Sea Hunter”—to the Office of Naval Research (ONR), the latter organization officially took over responsibility of developing the revolutionary prototype vehicle as the Medium Displacement Unmanned Surface Vehicle (MDUSV).

From 1971 to 1974, ARPA supported research on "glassy" carbon, a unique foam material composed of pure carbon and that combined low weight, high strength, and chemical inertness. The program led to techniques for producing the material with an exceptionally porous, high surface area combined with high rigidity, low resistance to fluid flow, and resistance to very high temperatures in a non-oxidizing environment.

Eyed originally for roles in electro-chemistry because of its high surface area, the material proved suitable for surgical implants, especially heart valves. Development of the valves began about three years after the end of the ARPA program, with production commencing in 1985. In 1990, the U.S. Food and Drug Administration (FDA) gave its approval for using glassy carbon in implants in a valve market that grew within the decade to 100,000 units and a market value of $200 million. A related form, pyrolytic carbon, remains common in the inner orifice and leaflets of artificial valves.


With the blue water threat of free-ranging, nuclear-armed Soviet submarines coming to a head in 1971, the Department of Defense (DoD) assigned DARPA a singular mission: Revamp the U.S. military’s anti-submarine warfare (ASW) capabilities to track enemy subs under the open ocean where the U.S. Navy’s existing Sound Surveillance System (SOSUS) was falling short. At the time, the U.S. Navy was already working on what would become its Surveillance Towed Array Sensor System, or SURTASS, through which surface ships towed long, mobile arrays of sensors to listen for submarine activity. Telemetry and data-handling issues greatly limited the system’s capabilities.

That’s when DARPA committed funds for the LAMBDA program to modify oil-industry-designed seismic towed arrays so they could detect submarine movement. DARPA-funded scientists began experiments at submarine depths, and soon generated spectacular results. In 1981, the DoD gave quick approval for production of a LAMBDA-enhanced SURTASS array, without requiring further study, a highly unusual decision for a program that had experienced a major technology shift late in the game. The system—which with DARPA participation would become enhanced by way of leading-edge computational tools, satellite-based data linkages, and computer networking—would become the Navy’s go-to method for tracking mobile Soviet subs for the remainder of the Cold War. By 1985, Secretary of the Navy John Lehman was so confident in his force’s ability to keep tabs on elusive Soviet boomers (a nickname for ballistic missile submarines), he declared that in the event the Cold War turned hot, he would attack Soviet subs “in the first five minutes of the war.”


In response to a call by Congress to establish a program to develop and efficiently transfer new hull, mechanical, and electrical technologies outside of normal U.S. Navy research and development channels, DARPA answered with the Advanced Submarine Technology (SUBTECH) program. Among ten technology demonstrations that successfully transitioned from the program to the Navy between 1989 and 1994 was the Non-Penetrating Periscope (NPP).

The NPP transformed submarine mast development when a prototype system using commercial visible and infrared spectrum cameras was built and demonstrated on the submarine USS Memphis in 1992. Using fiber optic data transmission, the new telescoping mast eliminated the need for the deep, hull-penetrating well that had been required to accommodate the optics tube on the then-current generation of submarines. The NPP also allowed greater flexibility in hull and interior design for future submarines.


Drawing inspiration from his work on the F-117 stealth aircraft, Ben Rich, then head of Lockheed’s Skunk Works, proposed applying the technology concepts he and his colleagues had learned for aircraft to submarines, with the idea of making these vessels undetectable via sonar. Initial tests on a small model suggested the stealth gains could be on the order of a thousandfold, albeit with a cost of speed due to the design.

The Department of Defense did not show interest in this line of investigation until Rich, with input from a colleague, adapted the idea to apply to surface ships. This led to a DARPA contract to apply stealth concepts and materials to surface vessels and to test the effects of seawater on the radar-absorbing materials.

Developed in great secrecy, a prototype, the Sea Shadow (also designated as IX-529) was assembled out of sight within a submersible barge (the Hughes Mining Barge 1) in Redwood City, California. The Sea Shadow’s first trials in 1981 proved greatly disappointing because the ship’s wake was unexpectedly huge and detectable with sonar and from the air. After discovering that the problem was due the motor propellers, which had been installed backwards, the project moved forward. The vessel was completed in 1984 and underwent night trials in 1985 and 1986. Even so, the Sea Shadow never made it beyond the testing phase, though engineers applied lessons learned in such applications as submarine periscopes and some newer Navy destroyers, including the DDG 1000 Zumwalt-class ships. In 1993, the public got it first view of the stealth ship, which eventually was scrapped in 2006.