The Defense Advanced Research Projects Agency (DARPA) awarded BAE Systems a $4.6 million contract for a program to allow submarines to detect other submarines at longer distances, the company said on July 18.

The contract covers the Mobile Offboard Clandestine Communications and Approach (MOCCA) program which aims to reach a breakthrough capability for extended range submarine detection and precision target tracking. DARPA is pursuing this because adversary submarine quieting technology “challenges passive anti-submarine warfare sonar detection range and performance,” the agency said on a website briefly describing MOCCA.

MOCCA uses collaborative operations using unmanned vehicles and active sonar techniques, DARPA said. The original Broad Agency Announcement (BAA) for the program noted MOCCA seeks active sonar solutions to mitigate the limits of passive submarine sonar sensors. The original presolicitation was posted in January 2016.

BAE noted the MOCCA goal is to detect submarines at greater distances while also minimizing the risk of counter-detection.

“With the resurgence of near-peer competitors and an increasing number of submarines, MOCCA technology will provide Navy submariners with a vital asymmetrical advantage against a rapidly proliferating undersea threat,” Geoff Edelson, director of maritime systems and technology at BAE Systems, said in a statement.

The MOCCAA BAA calls for a submarine with the ability to coordinate the operational functions of the supporting unmanned undersea vessel (UUV) and thus demonstrate the ability to achieve reliable clandestine communications between the submarine and UUV without sacrificing submarine stealth.

The overall program has two main technical challenges: develop an active sonar system which includes a small form factor active sonar projectile usable for UUV operations design and implement a secure and reliable communications link for positive control of a UUV operating at a “significant” distance from the mother submarine, the BAA said.

Phase 1 of the MOCCA program will move the necessary technologies form conceptual design to preliminary system design over 15 months. This includes technical area activities like requirements analysis, design studies, prototype development, risk analysis and a demonstration of critical design technologies to show evidence of viability.

BAE said to meet these Phase 1 goals, company researchers “will design efficient sonar capabilities to maximize detection range and improve target identification and tracking.”

After Phase 1 is finished, performers are to develop a technology maturation plan to describe the approach to continued development and platform integration into UUV and submarine systems.

DARPA said a follow-on BAA is possible if MOCCAA Phase 1 is successful. In that case, DARPA may release a solicitation for Phase 2, which may also include an option for Phase 3. Phase 2 would be an 18-month effort focused on the system-level development of MOCCAA solutions and integrate Phase 1 sonar and communications solutions into a test UUV platform. It would culminate in at-sea system-level demonstrations to evaluate MOCCA performance.

Phase 3 would be an 18-month effort to complete development of a MOCCA system with submarine integration and conduct an operationally realistic at-sea demonstration of an end-to-end system.