Raytheon plans to launch a small unmanned air vehicle from a submerged U.S. Navy submarine early next year to demonstrate its concept for extending the boat's sensor range in littoral operations.
Last month the company demonstrated its UAV launch concept under Phase 1 of the Submarine Over the Horizon Organic Capabilities (Sothoc) program funded by the Office of Naval Research and the Submarine Force.
The concept uses a submarine launch vehicle (SLV) containing the electrically powered UAV and stored on board as an all-up round. Ejected from the submerged submarine's trash disposal unit, the SLV is weighted to descend to a safe distance from the boat, then shed the weight and inflate a float collar.
The collar is pulsed to control the rate of ascent. As it approaches the surface, the SLV deploys a water drogue to provide stabilization and a vane to align it into the wind. The tube then pivots to a 35-degree angle and ejects the UAV.
"The SLV is a method of getting a UAS to the surface dry, then transitioning it to the air," says Jeffrey Zerbe, Raytheon's Sothoc program director.
The deployment concept was demonstrated in September at the Naval Undersea Warfare Center's shallow water test range at Narragansett Bay, R.I., where two SLVs were deployed over the side of a surface ship.
"The vehicles descended to 80 feet reverted to positive buoyancy, floated to the surface, stabilized in variable sea states, aligned into the wind, and then launched an inert representative UAS at precise orientation and velocity," according to Raytheon.
In early November, Zerbe says, the company plans to conduct a second "over-the-side" demonstration from a ship off Point Mugu, Calif. This time the SLV will deploy an actual UAV, which will then conduct a full maritime interdiction mission profile.
This will be followed early next year by a launch from a submerged submarine, probably a Los Angeles-class boat off Hawaii, under Phase 2 of the program, says Zerbe. Raytheon has already demonstrated integration of its multi-vehicle control software into the submarine's BYG-1 combat system, he says.
Raytheon will use "a mature small UAV" for the demonstration, says Zerbe, and the electrically powered, folding-wing air vehicle is capable of being launched in wind speeds up to 20-30 knots. The submarine-launched UAV is intended to be expendable, although it could be recovered via a beach, he says.
Zerbe says the UAV launcher is part of a system concept to provide real-time situational awareness to submarines at significantly increased ranges. This includes to ability to work with other UAVs that may be operating in the area.
AviationWeek.com. October, 2008
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