Exploring Titan's cryogenic hydrocarbon seas with boat-deployed expendable dropsondes

We present a preliminary design for a 3 kg expendable measurement system to descend to a depth of up to 1 km in the cryogenic hydrocarbon seas (Kraken and Ligeia Mare) of Saturn's moon Titan. These could profile the temperature and gross composition (methane/ethane) and providing information on the constitution of the seabed. Particular features of the Titan environment distinct from Earth are (1) the interior of this small vehicle must be thermally isolated from the 94 K liquid (2) 1 km depth on Titan entails overpressures of only 10 bar, and (3) that the low dielectric loss of the liquid allows data transmission by radio link. A surface vessel equipped with such expendable dropsondes could accomplish much of the science previously considered for submersible vehicles, while avoiding the challenges of buoyancy control.