Drifting buoy and autonomous submersible designs for the scientific exploration of Titan's seas

The Cassini spacecraft has revealed that Saturn's frigid moon Titan has north polar seas of liquid methane and ethane. Titan serves as a new laboratory for physical oceanography, with familiar processes such as air-sea gas and heat exchange, and the generation of waves and circulation by wind, occurring under instructively different conditions from Earth. There are indications that Titan's seas have varied in extent due to astronomical and geological climate forcing, and shoreline and seabed deposits may bear a record of this evolution. NASA studies have begun to explore platform designs for the exploration of these seas. Particular factors that differentiate ocean exploration on Titan vs on Earth are the need for autonomy in deployment and operation, the cryogenic temperatures, the non-polar (radio-transparent and electrically-insulating) and volatile character of the liquid, and the means for communication with Earth. The relative merits of submersible and floating platforms are discussed.