The U.S. Navy has successfully demonstrated a robotic system designed to refuel unmanned surface vessels (USVs) while operating at sea, as part of efforts to keep autonomous vessels on station for longer periods without returning to port.

According to the U.S. Navy, the August 11 demonstration was conducted off Joint Expeditionary Base Little Creek-Fort Story in Virginia. A T38 unmanned surface vessel repeatedly approached a towable capture and connection device, which allowed the vessel to be captured, refueled and released while at sea.

During the demonstration and related testing, the system completed about 100 connection cycles. The training support vessel USNS Vindicator towed the refueling device and transferred a total of approximately 400 gallons of fuel to the unmanned vessel. The Navy said the technology could reduce reliance on crewed support vessels during extended unmanned operations.

The Naval Air Warfare Center Weapons Division said the next phase will focus on an end-to-end autonomous refueling demonstration. The planned test will cover vessel rendezvous and approach, capture, fuel transfer, disconnection and return to mission with reduced human involvement.