The Applied Physics Laboratory at Johns Hopkins University has released CRACUNS, a new UAV that can operate in the water or in the air. CRACUNS (Corrosion Resistant Aerial Covert Unmanned Nautical System) can be launched from an unmanned underwater vehicle with a payload and survive in salt water.
The frame is built from composites to be strong and lightweight, with no metal or machined surfaces. The payload and controller components sit inside a pressure vessel constructed using additive manufacturing. The motors spinning the rotors could not be placed inside the water proof container so they needed to be waterproof and resistant to corrosion. Off the shelf waterproof coatings were used to shield the motors, and a two month salt water bath test showed that the motors could operate while submerged with no corrosion issues. Wires wrapped around the arms of the frame are an odd choice, leading me to think that the composite arms of the frame are solid or honeycombed.
CRACUNS have been tested at a depth of 'several hundred feet' for launching, operation, and general survival. The manufacturing methods and materials are relatively low cost will allow for companies to build large numbers of CRACUNS for dangerous missions.
Johns Hopkins Applied Science Lab is aligned closely with military and defense, with their mission statement 'Enhancing national security through science and technology'. This video mentions the needs of their sponsors a few times as a driving force for the development of CRACUNS. It's amazing to see drone technology advanced like this and I can easily imagine a set of wheels incorporated to make this an air / land / sea machine. This is a great project that shows the fundamental process of engineering design - the lab had a product in mind, looked at the greatest challenges for the design, and then found methods to overcome those challenges.
CRACUNS has previous exposure from the 2015 AUVSI conference, appearing onstage with Secretary of the Navy Ray Mabus. The Applied Physics Laboratory is a busy place, with this press released issued eight days ago but three new stories already posted about the lab's work with solar arrays, first responder data forecasting, and space exploration.
(Images courtesy the Johns Hopkins University Applied Physics Laboratory)