Defense Advanced Research Projects AgencyTagged Content List

Maritime Systems

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

Showing 85 results for Maritime RSS
01/01/1971

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.”

01/01/1992

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.

01/01/1984

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.

01/11/2013
Today, cost and complexity limit the Navy to fewer weapons systems and platforms, so resources are strained to operate over vast maritime areas. Unmanned systems and sensors are commonly envisioned to fill coverage gaps and deliver action at a distance. However, for all of the advances in sensing, autonomy, and unmanned platforms in recent years, the usefulness of such technology becomes academic when faced with the question, “How do you get the systems there?” DARPA’s Upward Falling Payloads program seeks to address that challenge.
03/01/2013
Effective 21st-century warfare requires the ability to conduct airborne intelligence, surveillance and reconnaissance (ISR) and strike mobile targets anywhere, around the clock. Current technologies, however, have their limitations. Helicopters are relatively limited in their distance and flight time. Fixed-wing manned and unmanned aircraft can fly farther and longer but require either aircraft carriers or large, fixed land bases with runways often longer than a mile. Moreover, establishing these bases or deploying carriers requires substantial financial, diplomatic and security commitments that are incompatible with rapid response.