Alien oceans may or may not mean that something is swimming beneath the surface, but a space submarine is the only way to find out.
NASA wants to send an amphibious spacecraft to take the plunge into Kraken Mare, the appropriately named sea of Saturn’s largest moon, Titan, by 2025. But. The space agency needs to make sure it won’t drown — or burn up in the atmosphere before even that could happen. Enter the most awesome thing to be happening in a lab at Washington State University.
WSU has joined forces with NASA to build something that would have sounded straight out of science fiction half a century ago (and still kind of does). To figure out how an unmanned submarine would make it to the Saturnian moon and back, WSU researchers have recreated Titan’s freezing -300° F methane and ethane waters. Titan is the only known object in space to have liquid bodies of water on its surface, which gives it one similarity to Earth, even if the chemical soup of those rivers, lakes, and oceans would kill anything from this planet.
What the WSU team wanted to find out was “the solubility of nitrogen in varying liquid methane-ethane compositions and the effects of dissolved nitrogen on the density of the sea,” as former WSU grad student Ian Richardson and colleagues said in a study recently published in the journal Fluid Phase Equilibria.
Cassini (RIP) beamed data back to NASA whenever it hovered over Titan until its fatal descent into the rings of Saturn last year. Even if the future submarine doesn’t find any strange life-forms, anything we find out about these mysterious depths could tell us more about Earth. For this thing to actually work, it will need to withstand the drastic differences between concentrations of ethane and methane as it maneuvers from ocean to ocean and through the atmosphere.
To make sure the sub will survive, Richardson and his team built a test chamber for their version of a Titanian sea, with a cylindrical cartridge heater to simulate the heat from a submarine passing through. What the researchers needed to understand the most was what would happen when a heat-generating spacecraft increased the amount of nitrogen gas that would bubble up in those subzero seas while being exposed to 60 pounds per square inch of pressure. An overflow of bubbles would get in the way of the ship’s navigation, ballast systems, and data collection.
“Those aren’t the friendliest conditions,” Richardson admitted. “You have to come up with creative solutions.” At least the lakes were found to freeze at lower temperatures than he thought they would.
To think, this is just phase one.