The Defense Advanced Research Projects Agency (DARPA) awarded contracts to Northrop Grumman [NOC] and

Martin Defense Group to move to Phase 2 of the Manta Ray unmanned undersea vehicle (UUV) program, the agency said Monday.

In this phase, the companies will work on subsystem testing before moving to fabricate full-scale models to use for in-water demonstrations. The Manta Ray effort aims to demonstrate technologies to allow payload-capable autonomous UUVs “to operate on long-duration, long-range missions in ocean environments,” the agency said.

It also said Manta Ray UUVs are being developed to operate for extended durations “without the need for on-site human logistics support or maintenance.”

DARPA’s program website said UUVs like the Manta Ray are trying to demonstrate technologies for a new class of UUVs. Such vehicles that can operate for long periods without human-present logistic support or maintenance “offer the potential for persistent operations in forward environments. Such systems could allow traditional host vessels increased freedom of operational flexibility while providing traditional servicing ports with relief of workload.”

Phase 1 began in 2020, when performers designed and conducted preliminary testing on “novel approaches” in energy management, UUV reliability, biofouling and corrosion control, navigation, and undersea obstacle avoidance.

Last February, DARPA executed contract options to continue the Manta Ray with Northrop Grumman, Martin Defense Group and Metron, Inc. after it completed preliminary design reviews. While the first two are on a trajectory to build full-scale vehicles, Metro is set to continue working on an energy harvesting subsystem as part of the larger “novel energy management techniques” the program lists as a key technology for the vehicle.

Phase 1 ended earlier this year with Critical Design Reviews that demonstrated maturity and readiness to move to the next phase.

DARPA published a video showing how the Manta Ray could operate. The UUV operates very close to the seafloor and at one point rests on the seafloor to deploy a small sensor payload before it returns to the vehicle.

“DARPA’s Manta Ray program has made significant breakthroughs toward enabling payload-capable autonomous underwater vehicles to operate independently of crewed vessels or support infrastructure,” Cmdr. Kyle Woerner, Manta Ray’s program manager, said in a statement.

“By investing in diverse solutions, DARPA strengthens our ability to transition innovative undersea technologies to our national security partners. Manta Ray is uniquely positioning itself to simultaneously introduce a new class of underwater vehicle while contributing key component technologies to other vital undersea programs,” Woerner added.