Saturn is orbited by 62 official moons, the largest of which is Titan. However, Titan is not your average satellite - larger than the planet Mercury, Titan has a thick nitrogen atmosphere and a large liquid hydrocarbon lakes on the surface. Unfortunately, it has been difficult to obtain much information about the lakes’ depth or composition from the orbital missions. NASA has recently revealed what a conceptual submarine mission to Kraken Mare, the largest sea on Titan, would look like. Kraken Mare contains enough liquid methane to fill Lake Michigan three times over. Conditions are presumed to be rough, with changing tides and massive waves.
The hypothetical submarine would travel about 2,000 kilometers (1,250 miles) over the course of a 90 day mission. While the craft wouldn’t have a problem staying under the sea during that time and diving, it will need to surface in order to transmit data back to Earth. It would be powered by a radioisotope thermoelectric generator which doesn’t have moving parts, making it a good choice for a craft with such a long journey and will be dropped into the sea. Most of the power will be used to propel the submarine while under the surface, but will be capable of performing science missions as well.
During the mission, the submarine would make a number of observations and collect data using a variety of instruments. Some of the main objectives would be to analyze the chemical composition of the liquid, but also other oceanographic features such as currents and tidal patterns. The craft would also be equipped with cameras in order to image Titan’s shoreline and landscape. The science goals are pretty vague at such an early juncture, but would be more refined and detailed if the mission planning continues.
It is unknown when such a mission would ever take place, as this is really just the first rough draft of what could be used to explore Titan’s Kraken Mare with a submarine. There are a number of technological and logistical obstacles to address before any proposed launch dates are developed, including Titan’s orbit around Saturn. It takes nearly 30 Earth years for Titan to revolve around the planet, which will influence when such a mission could take place.
Other proposed missions to explore Titan’s seas include the Titan Mare Explorer (TiME) mission proposed in 2009, which functions more like a buoy than a boat. Unfortunately, the mission has been scrapped due to lack of development of the proposed fuel source. However, a similar mission would likely precede an extensive submarine mission, as is proposed here:
[Hat tip: io9]