Ask someone to picture a robotic roving vehicle, and chances are they’ll think of something with wheels, like the Mars Rover. If an alien civilization were sending a craft to explore Earth, however, they might be better off using a boat – after all, the majority of our planet’s surface is covered with water. Saturn’s largest moon, Titan, similarly has a pretty wet surface, as it contains lakes of liquid hydrocarbon. Wolfgang Fink, an engineer with the University of Arizona, has designed an aquatic rover for exploring those lakes.
Named the Tucson Explorer II, or TEX II, the catamaran-style "lake lander" has two Styrofoam hulls, each six feet (1.8 meters) long. Mounted on top of them is a raised deck, that can carry up to 150 pounds (68 kg) of computers, batteries and sensors. Those sensors presently include cameras, and sonar that can penetrate the water to a depth of 328 feet (100 meters), but a host of others could be added.
Two above-water electrically-driven propellers are located at the back of TEX II, each one of which can independently spin its blades in either direction. This allows the robot to move forward or backward, turn to either side, or pivot on the spot – something that couldn’t be done using a single source of propulsion. Because the propellers are located far apart from one another, maximum torque can be applied when using them to turn the craft.
In its current form, TEX II weighs 100 pounds (45 kg). Its top speed could be determined by the number of motors used, although its sonar reportedly works best at speeds no higher than 5 knots.
Previously, Fink had designed a land-based planetary rover. Both vehicles are part of his NASA award-winning concept of a complete system, in which a satellite would scan the surface of a planet, then send a blimp in that planet’s atmosphere to areas of interest. That blimp, in turn, would coordinate the movements of land and water rovers on the planet’s surface, to investigate those areas and collect samples. All of the machines involved would be autonomous, deciding for themselves what to do, and how to go about doing it.
Given that TEX II may not be traveling to Titan anytime soon, however, Fink believes that it should be useful for exploring our own planet. He suggests that it could be used for duties including harbor surveillance, hazardous cleanup operations, search and rescue efforts, and environmental research. Although it’s not fully autonomous – yet – it can be remotely controlled from anywhere in the world via the internet.
TEX II can be seen in action in the video below.
Source: University of Arizona via Dvice
You can't correctly test the aerodynamics here on earth. The craft would probably have too much lift on titan and become totally unstable when it leaves the liquid surface that it was designed to travel on.
If your going to operate on "water" wouldn't a sail provide more efficient propulsion. And you could use paddle wheels to generate electricity and to provide emergency propulsion.