Saturn's frigid moon Titan, visited by the Huygens probe in 2005, has a thick atmosphere and three vast northern polar seas of methane and ethane : these seas are of particular interest for future explora- tion. These seas have a composition and conditions (1.5 bar, 92K) rather similar to those of Liquefied Nat- ural Gas (LNG) on Earth. The largest, Kraken Mare, is 1000km in extent but of unknown depth: its complex shoreline morphology and evaporite deposits mapped by Cassini hint at a rich chemistry and climate history. We have developed a practical design for a robot sub- mersible to explore this exotic environment, drawing on experience in terrestrial AUVs/UUVs as well as spacecraft systems. The proposed ~1-tonne vehicle, with a radioisotope Stirling generator power source, would be delivered to splashdown circa 2040, to make a ~90-day, ~2000km voyage of exploration around the perimeter, and across the central depths of, Kraken
One of the first visitors to Jupiter's icy moon of Europa could be a tiny submarine barely larger than two soda cans. The small craft might help strike the right balance between cost and capability for a robotic mission to look for alien life in the ocean beneath Europa's icy crust.
The idea for the incredible shrinking submarine originally came from NASA’s Jet Propulsion Laboratory (JPL) in California and Uppsala University in Sweden. Such a vehicle would help keep mission costs low at a time when launching objects into space can still cost tens of thousands of dollars per kilogram. The mission concept also would have the advantage of only requiring a small borehole drilled through the ice covering Europa's surface.