Boeing was awarded a $43 million for delivery of four giant unmanned submarines for the U.S. Navy, the U.S. Defense Department said on Wednesday.

The department said the Boeing is awarded a $43 million modification to previously awarded contract for the fabrication, test, and delivery of four Extra Large Unmanned Undersea Vehicles (XLUUVs) and associated support elements. 

New giant unmanned submarine is a fully autonomous extra large unmanned undersea vehicle (XLUUV) class UUV that can be used for a variety of missions that were previously impossible due to traditional UUV limitations.

According to a statement, the XLUUV will be modular in construction with the core vehicle providing guidance and control, navigation, autonomy, situational awareness, core communications, power distribution, energy and power, propulsion and maneuvering, and mission sensors.

In a statement, the U.S. Defense Department called the new unmanned submarine as the Orca and added that vehicle will have a modular payload bay, with defined interfaces to support current and future payloads for employment from the vehicle. 

The Orca XLUUV will have well-defined interfaces for the potential of implementing cost-effective upgrades in future increments to leverage advances in technology and respond to threat changes.

Per the award, Boeing’s work on its giant unmanned submarines is expected to be completed by June 2022. 

Boeing has designed and operated manned and unmanned deep sea systems since the 1960s, including Rockwell International legacy systems and U.S. Navy support programs.