After more than a decade of effort the U.S. Navy has finally found a submarine launched UAV it wants to use. The Blackwing is stored and launched from a 75mm diameter canister that fits the launcher used for acoustic countermeasures devices (noisemakers that cause torpedoes to miss the sub). Blackwing would be used for finding and identifying distant targets. Blackwing is also equipped to be a communications relay. The UAV communicates with the sub via the OE-538 communications mast (a periscope type device the pokes out of the water while the sub is still submerged. The navy is buying 150 Blackwings initially.
Blackwing is not the first UAV designed for submarine launcher. The navy has been working on this sort of thing for over a decade. Back in 2006 the navy seriously considered a modified version of the recently introduced ScanEagle UAV for submarine use. This would be done by storing a ScanEagle in a canister that would be launched from one of the 533mm (21 inch) torpedo tubes.
ScanEagle weighs 19 kg (40 pounds), has a 3.2 meter (ten foot) wingspan, and uses day and night video cameras. On ships it uses a catapult for launch and is landed via a wing hook that catches a rope hanging from a 16 meter (fifty foot) pole. The ScanEagle can stay in the air for up to 24 hours per flight and fly as high as 6,100 meters (19,500 feet). ScanEagles’ cruising speed is 110 kilometers an hour and can operate over a hundred kilometers from the ground controller. Scan Eagle carries an optical system that is stabilized to keep the cameras focused on an object while the UAV moves. ScanEagle has been in military service since 2005 and was used by civilian operators for several years before that. There were too many problems (and it was too expensive) to modify ScanEagle for launch via a torpedo tube. It might have worked in theory but the navy decided to wait for better UAV technology to show up and Blackwing appears to be it.