The US Defense Advanced Research Projects Agency (DARPA) demonstrated the first at-sea refueling of the No Manning Required Ship (NOMARS) program.
A pair of unmanned surface vessels (USV) — the Ranger and the Mariner — demonstrated the task originally designed for the program’s Defiant USV.
A long-endurance NOMARS USV is intended to be designed from the ground up without the necessity for humans on board.
The design’s advantages include “size, cost, at-sea reliability, survivability to sea-state, and survivability to adversary actions such as stealth considerations and resistance to tampering,” according to DARPA.
Crewless Fueling at Sea
Though fueling at sea (FAS) for NOMARS is designed for crewless operation, personnel are required to be on the refueling vessel to handle lines and hoses on the platform being refueled.
“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,” DARPA added.
“It can also be risky and sometimes dangerous to transport personnel to a USV in rough seas or high winds.”
Crewless Fueling Test
For the unmanned FAS testing for NOMARS, the USV Mariner refueled the USV Ranger, which was carrying a representative system of the one on the NOMARS USV Defiant.
Though people were aboard both the vessels during the event, no one was involved with operations on the receiving vessel.
“The team demonstrated all parts of the system CONOPs (concept of operations) while underway, including passing the lead-line to the refueling side, passing and connecting the refueling probe to the USV side and pumping water,” the Pentagon agency explained.
“This was the first on-water test of the system, and all parts of the operation were successfully demonstrated.
DARPA could not have accomplished this test without the support and partnership of Navy PMS-406 and USVRON-1, both of whom contributed personnel and resources.”
No Manning Required Ship
Serco is the prime contractor to build the program’s testbed Defiant.
It is intended to be a low-cost, unmanned vessel to remain at sea for months or years with minimal maintenance.
Specific mission sets of the 210-ton vessel are not known. However, it is likely to carry a “significant payload at tactically useful ranges.”
“The goal is to achieve ultra-reliability objectives by integrating distributed hybrid power generation, podded propulsors, and high-capacity batteries,” DARPA added.
“A key philosophy of NOMARS is ‘graceful degradation,’ which allows individual equipment to fail over time by having enough system-level redundancy to meet full system requirements at speeds of at least 15 knots after one year at sea.”
