The Navy is honing its methods for at-sea drone refueling.
The USS Chafee on Sept. 11 refueled the Unmanned Surface Vessel Seahawk, Medium Unmanned Surface Vessel, according to Navy photos released on Monday. The refueling of the uncrewed vessel, which requires onboarding personnel to the Seahawk, was the second time a U.S. Navy ship attempted an at-sea sustainment this year.
The astern refueling method was previously tested between Seahawk and oiler USNS Guadalupe in April, according to USNI.
The Seahawk joins the other MUSV, Sea Hunter, as the first autonomous medium unmanned surface vessels operated by the Defense Advanced Research Projects Agency and the Office of Naval Research.
The sea service is utilizing the “Sea Hunter and Seahawk as prototypes for research and experimentation. Major goals of research and experimentation efforts with Sea Hunter and Seahawk are to determine the most effective way to utilize USVs in operations and how to best integrate them into the Fleet,” according to the Navy.
The 145-ton Seahawk was built by the tech and defense company Leidos, before being transferred to the Navy in 2021 and used for testing across the Indo-Pacific.
Through its No Manning Required Ship — or NOMARS — program, DARPA is working to codify its USV refueling system that currently presents significant risk to sailors working to refuel it.
According to a 2024 DARPA report, “Requiring personnel on the USV for the operation adds significant constraints on USV design and operations, as the vessel must then be designed with considerations for safety of the humans on board, even if for a short period of time. It can also be risky and sometimes dangerous to transport personnel to a USV in rough seas or high winds.”
The latest at-sea refueling marks a significant step for the Navy as it works to rapidly expand its uncrewed surface vehicle fleet.
The Navy’s shipbuilding plan, released in May, requests funding for five unmanned and 34 manned vessels in Fiscal Year 2027. Over the next five years, it asks for 63 unmanned platforms and 122 manned ships, for a total of 299 manned battle-force ships and 83 unmanned vessels by FY 2031. It was the first time the Navy had included unmanned vessels in its future fleet projections.
Hope Hodge Seck contributed to this report.
Claire Barrett is an editor and military history correspondent for Military Times. She holds a master’s degree in military history from King’s College, London, and is also a World War II researcher with an unparalleled affinity for Sir Winston Churchill and Michigan football.