In our solar system, there are only two planetary bodies with liquid lakes and seas-Earth and Titan, a moon of Saturn. But instead of water, Titan lakes are made of liquid methane with temperatures registering at almost -300 F.

So how would NASA study this interesting place? Steve Oleson of NASA Glenn's COMPASS Lab (Collaborative Modeling for Parametric Assessment of Space Systems) believes the team, along with partners from the Johns Hopkins Applied Physics Lab and the Penn State University Applied Research Lab have come up with an innovative answer.

"We have developed a concept to send a submarine to Titan's largest northern sea," says Oleson. "This craft would be loaded with scientific instruments that could carry out detailed investigations under the surface providing unprecedented knowledge of an extraterrestrial sea."

A 90-day, 1,250-mile voyage exploring Kraken Mare, a sea comparable in size to the Great Lakes, is proposed.

"The mission concept will investigate a full spectrum of oceanographic phenomena: chemical composition of the liquid, surface and subsurface currents, mixing and layering in the "water" column, tides, wind and waves, bathymetry, and bottom features and composition," explains Oleson. "Measurements of all these aspects of Titan's hydrocarbon ocean environment can only be made through focused exploration with a well-instrumented craft."

Communicating with Earth would not be possible when the vehicle is submerged, so it would need to make regular trips to the surface to transmit science data. Due to the length of time needed to develop the hardware, travel time and the fact that seasons last seven years on Titan, Oleson and his team propose a launch in the 2040s, one of the summer periods.

If the Titan submarine concept is chosen by NASA to develop further, NASA Glenn expertise in radioisotope power, sensor and communications systems would be incorporated into the design.

The COMPASS team presented its idea to NASA's Innovative Advanced Concepts (NIAC) Symposium in February where visionary ideas that could transform future NASA missions are presented for consideration. NIAC projects study innovative, technically credible, advanced concepts that could one day "change the possible" in aerospace.