This aquatic vehicle is part of DARPA’s Mobile Offboard Clandestine Communications and Approach (MOCCA) program, designed to increase the effectiveness and reach of the US Navy’s underwater sensors using advanced technology. If successful, the program will help alleviate projected shortfalls into the 2020s by providing the US submarine fleet with vital new capabilities.
The MOCCA program was designed to supply "extended range submarine detection and precision target tracking through collaborative operations using unmanned vehicles and active sonar techniques," according to DARPA.
"The objective is to achieve significant standoff detection and tracking range through the use of an active sonar projector deployed offboard a submarine and onboard an Unmanned Underwater Vehicle (UUV). The submarine will need the ability to coordinate the operational functions of the supporting UUV. Thus, the program must also demonstrate the ability to achieve reliable clandestine communications between the host submarine and supporting UUV without sacrificing submarine stealth," the contract solicitation states.
Active sonar, which sends out bursts of sound energy to see if sound reflects off objects like ship hulls, is rarely used by submarines, as stealth is the vessels’ chief defense attribute, and enemy vessels using passive sonar could find their position by listening to them, the Diplomat explained.
The UUV must be 21 inches in diameter or smaller, according to the contract, making it the right size to fit the 21-inch torpedo tubes featured on Virginia-class submarines. There are a number of technical issues that will have to be dealt with, as the vehicle’s location can be given away if the sonar isn’t properly directed, and the UUV’s diminutive size will affect how effective its sonar suite is.
This could create an problem for a submarine fleet that needs growth. Admiral Harry Harris, head of US Pacific Command (USPACOM) told Congress in February 2016 that the Navy’s submarine fleet is the US’ "principal asymmetric advantage over China," which is rapidly expanding its fleet.
Harris pointed out that the service can only provide about half of the submarines it needs to meet operational requirements, and some reports posit that Beijing’s navy could outgrow Washington’s by 2020.
MOCCA is important for the Navy because of these shortfalls, as the new system "will provide Navy submariners with a vital asymmetrical advantage against a rapidly proliferating undersea threat," according to a BAE Systems release.
"Advances in maritime technology are critical to the Department of Defense and an area where the US military can continue to strengthen its advantage," BAE Director of Maritime Systems and Technology Geoff Edelson said in the release. "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."