Knifefish (robot)
Autonomous UUV for mine detection, replacing Navy marine mammals.
The Knifefish is a torpedo-shaped, propeller-driven autonomous underwater vehicle being built by General Dynamics Mission Systems and Bluefin Robotics for the U.S. Navy. It is designed to hunt and mark naval mines, taking over a role once filled by the Navy’s trained dolphins and sea lions after the Marine Mammal Program ended in 2017. The robot was first shown at a Navy exposition in April 2012 and was planned to work alongside the Navy’s littoral combat ships as part of a mine-countermeasure system. It saw action in the 2026 Strait of Hormuz campaign.
The Knifefish is based on the Bluefin-21, a civilian UUV from Bluefin Robotics in Quincy, Massachusetts. That model became widely known in 2014 when it searched the Indian Ocean floor for wreckage of Malaysia Airlines Flight 370. The Knifefish measures 22 feet long and 21 inches in diameter, weighs 2,000 pounds, and runs on a lithium-ion battery that gives it up to 16 hours of endurance on pre-programmed missions. It uses onboard synthetic aperture sonar to detect mines—both floating and buried—and identifies them with an internal database and analytical computer. After marking a mine and recording its location, the robot uploads the data to its parent littoral combat ship, which then destroys the mine. The Navy may later add real-time data transmission if sea trials show it is needed. Each LCS can operate two Knifefish vehicles, which scan the seabed nearby to reduce the risk of mine damage to the ship.
The Navy is looking into boosting the Knifefish’s endurance so it can handle minehunting as well as searching for buried and high-clutter mines. Because of reliability problems with the Remote Multimission Vehicle, only ten of those will be upgraded and fielded in 2018. The Navy also plans to add a towed sonar to the Common Unmanned Surface Vehicle for use by 2020. For certain mine-countermeasure jobs, the Knifefish outperforms the RMMV, but it lacks the endurance to cover large minefields. If its endurance improves, the mine-countermeasure package would become simpler—since the sensor is built into the vehicle rather than towed—and the CUSV would only be used for minesweeping.
By December 2012, the Navy had ordered eight Knifefish units for a total of $20 million. In April 2013, General Dynamics completed the critical design review and started developing software and hardware for the operational version.
Quick Facts
- Imsize
- 250
- Manufacturer
- General Dynamics Mission Systems / Bluefin Robotics
- Country
- United States
- Year Of Creation
- 2012 (initial unveiling)
- Purpose
- Minesweeping
Facts from the source article.
Lore & Background
The Knifefish is a derivative of the Bluefin-21, a civilian UUV designed by Bluefin Robotics of Quincy, Massachusetts. In 2014, the Bluefin-21 gained widespread recognition after it was deployed to search the seafloor of the Indian Ocean for the wreckage of Malaysia Airlines Flight 370. The Knifefish is a torpedo-shaped robot 22 ft in length and 21 in in diameter, with an operational weight of 2000 lb. It is powered by a lithium-ion battery, which allows it to operate for up to 16 hours on pre-programmed search missions. It uses onboard synthetic aperture sonar to detect floating or buried naval mines, and can identify a wide variety of mines and mine-like objects using an onboard database and analytical computer. The Knifefish can then mark detected mines and record their locations in its database; the robot later uploads the data to its parent LCS, which destroys the mines. The Knifefish may be modified to transmit its data in real-time, if the Navy considers such a capability necessary after the robot's sea trials. Each LCS will be capable of operating two Knifefish UUVs, which will scan the seabed near the ship and reduce the risk of mine damage to the LCS itself.
Reader's Guide
The Knifefish represents a shift from biological to robotic mine countermeasures for the U.S. Navy, following the retirement of the Marine Mammal Program in 2017. Its development began with an order of eight units in December 2012 at a total cost of US$20 million, and a critical design review was completed in April 2013. Sea acceptance testings were completed off the coast of Massachusetts in 2018. On 20 July 2020, the U.S. Department of Defense awarded General Dynamics roughly $13.5 million for ongoing engineering on the Knifefish. General Dynamics Mission Systems opened a new UUV manufacturing facility at its Taunton, Massachusetts, facility in August 2021, dedicated to the Knifefish and Bluefin Robotics UUV range. The Navy is considering increasing the endurance of the Knifefish to take over minehunting in addition to searching for buried and high-clutter mines. Due to reliability issues with the Remote Multimission Vehicle (RMMV), only 10 will be upgraded and fielded in 2018. For certain mine countermeasure missions, the Knifefish is superior to the RMMV, but it does not have the endurance to cover large minefields; if endurance can be enhanced, the MCM package would be simplified, as the sensor is embedded in the vehicle rather than towed, and the Common Unmanned Surface Vehicle (CUSV) would only be used for minesweeping.
Did You Know?
- The Knifefish is a derivative of the Bluefin-21, which searched for Malaysia Airlines Flight 370 wreckage in 2014.
- It was first unveiled at a Navy exposition in April 2012.
- The robot was used by the US in the 2026 Strait of Hormuz campaign.
- Each littoral combat ship can operate two Knifefish UUVs.
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