Scientists from the National Aeronautics and Space Administration (NASA) unveiled the design for a new submarine intended to explore not the depths of Earth's own oceans but that of the oceans of Titan, the largest moon that orbits Saturn.
At this week's NASA Institute for Advanced Concepts (NIAC) symposium held in Cocoa Beach in Florida, scientists at the NASA Glenn Research Center presented the Titan Submarine Phase I Conceptual Design.
The unveiling showed NASA's concept of an autonomous submersible vehicle that is patterned largely on Earth's own submarines but equipped with the ability to survive the liquid methane oceans found on the surface of Titan.
Following the Cassini flyby probe and the European Huygen mission that landed on Titan's Earth-like topography, one where the hydrocarbon rivers and lakes sculpted valleys into the land surface, it has been established that Titan has three large polar oceans composed of liquid methane and ethane, which would make them similar to liquefied natural gas on Earth.
NASA is particularly interested in the Kraken Mare, the largest of the three oceans spanning 154,000 square miles over the moon's north pole and going as deep as 160 meters by some estimates and 300 meters by others.
Like our oceans on Earth, Kraken Mare has tides due to the gravitational pool of Saturn and a complex shoreline lined with deposits of a mineral sediment called evaporite, which all suggest Titan has a rich chemistry and climate history waiting to be uncovered.
Because of Titan's vastly different composition from Earth and the 80 light-years of distance between our planet and Saturn's moon, NASA has plenty of challenges to overcome before it can actually launch a submarine into space.
The Titan submarine will have an elongated shape and will weigh 2,200 lbs, or one ton. Because of its weight, it can't simply be dropped off like the Curiosity rover on Mars. Instead, the submarine will have to be delivered via something like a modified version of the U.S. Air Force X-37 space plane, which can handle hypersonic entry into the foggy atmosphere of the moon.
Once inside Titan's atmosphere, NASA has other formidable issues to contend with, namely Kraken Mare itself, which is extremely cold with temperatures of -290 degrees Fahrenheit, almost near the freezing point of methane.
The submarine will use a 1kW radiothermal Stirling generator to produce one kilowatt of power that will allow it to travel at 2.2 miles per hour, but the excess heat generated by the submarine could cause the surrounding liquids to boil. Also, the submarine will require a special piston-driven system to prevent the nitrogen ballasts from freezing in the icy cold depths of Kraken Mare.
The submarine will also be largely autonomous, since the distance between Earth and Titan make real-time transmission of commands virtually impossible. It would take two hours for the submarine to receive communications from NASA.
For this reason, NASA wants the submarine to go back to the surface 16 hours every day to transmit data back to Earth using a planar phased array antenna mounted on a large dorsal fin. While on the surface, the submarine will also take images of the surrounding environment using a mast camera.
It's unclear what NASA hopes to discover with the submarine, but it wants to take the autonomous submersible on a 90-day, 1,250 mile voyage under the surface of Kraken Mare, although that mission won't be launching anytime soon. As per NASA's timeline, it hopes to send the actual submarine into space in 2040.
