Titan is Saturn’s largest moon, and it’s said to be one of the most Earth-like celestial bodies in the Solar System. It has a thick atmosphere, and is covered with a network of seas, lakes and rivers – albeit ones made up of liquid hydrocarbons instead of water. Now, a team of scientists are proposing sending a boat-like probe to Titan, that would travel across its largest lake.
The probe, which is still in the concept stage, is known as TALISE – that stands for Titan Lake In-situ Sampling Propelled Explorer, although it’s also an Iroquois word for “beautiful water.” The plan calls for it to land in the middle of Ligeia Mare, which is near the moon’s north pole. It would then set out on a six-month to one-year mission, taking scientific measurements and obtaining samples as it makes its way to the closest shore.
TALISE would weigh about 100 kilograms (220.5 lbs), and would be equipped with an assortment of scientific instruments including a magnetometer, a panoramic camera, an acoustic sounder and a Light Detection And Ranging (LiDAR) system.
It would move across the surface of the liquid hydrocarbons using either smooth wheels (really?), paddle wheels, or screw drives – all three systems are currently being considered. Earlier ideas that were ultimately rejected included tank tracks, above- and below-surface propellers, and a hovercraft design.
The development team, which consists of scientists from Spanish engineering firm SENER and the Centro de Astrobiología in Madrid, presented their project today at the European Planetary Science Congress, also in Madrid. They now plan on conducting a feasibility study and creating a preliminary mission architecture, so they’re ready whenever a future space mission starts seeking proposals.
Wolfgang Fink, an engineer with the University of Arizona, has already built a functioning prototype aquatic rover, also intended to traverse the lakes of Titan.
Source: Europlanet
Your propellers depend on the liquid being thin and free flowing where as paddle wheels and screw drives when properly designed can operate on free flowing liquids, solids, and anything in between while I would use 3 or 4 paddle wheels for the capability check this out. http://www.youtube.com/watch?v=zBjlSJf4274