Working in a -300 F ocean of methane and ethane has its challenges
Building a submarine gets tricky when the temperature drops to -300 Fahrenheit and the ocean is made of methane and ethane.
Sunlight glints off of Titan's northern seas this near-infrared, color mosaic from NASA's Cassini spacecraft.
Credit: NASA/JPL/Univ. Arizona/Univ. Idaho
Washington State University researchers are working with NASA to determine how a submarine might work on Titan, the largest of Saturn's many moons and the second largest in the solar system. The space agency plans to launch a real submarine into Titan seas in the next 20 years.
The researchers re-created a Titan ocean in a laboratory. They have published a paper on their work in the journal, Fluid Phase Equilibria.
Titan is of particular interest to researchers because it is similar to earth in one important way, it holds liquid. Unlike almost anywhere else in the solar system, the moon's surface includes oceans, rivers and clouds, and like on earth, it can rain. But, instead of water, the hydrological cycle is based on methane.
Because of the possible lessons it could provide here on Earth, NASA has been studying Saturn and its moons for more than a decade with data collected from the Cassini spacecraft.
The submarine that the agency is designing will have to operate autonomously. It will need to study atmospheric and ocean conditions, move around sea beds, and hover at or below the surface. The engineering is even trickier because, unlike the nearly homogeneous water in earth-based oceans, the concentration of ethane and methane can vary dramatically in the Titan oceans and change the liquid's density properties.
Ian Richardson, a former graduate student in the School of Mechanical and Materials Engineering, got the chance to tackle how NASA might build a submarine for the extreme conditions. In WSU's cryogenic lab, which studies materials at very cold temperatures, Richardson re-created the atmosphere of Titan and tested how a small heated machine might work under such conditions.
Richardson, who holds a bachelor's degree in mechanical engineering from WSU, has had a longtime interest in space and space exploration technologies. He was WSU's first-ever recipient of a NASA Space Technology Research Fellowship, which included an internship at NASA's Glenn Research Center in Cleveland, Ohio. It was while working as an intern on a separate problem that a NASA scientist approached him with the problem of designing a submarine for Titan.
"My research just took a right turn, and I went with it," said Richardson. "It's a crazy experiment, and I never thought I would have had this opportunity. It's been a very fun and challenging experimental design problem."
Simulating Titan seas
The WSU research team built a test chamber that housed the liquid mixture at very cold temperatures to simulate the seas of Titan. They added a two-inch, cylinder-shaped cartridge heater that would approximate the heat that a submarine would create.
One of the biggest challenges for researchers was understanding bubbles in the Titan seas. Add a submarine powered by a heat-producing machine into the very cold Titan liquid, and nitrogen bubbles will form. Too many bubbles would make it hard to maneuver the ship, see, take data and manage ballast systems.
Shooting video at -300 degrees
The next big problem, said Richardson, was getting a video in difficult conditions. Their study was conducted at 60 pounds per square inch of pressure and nearly -300 degrees Fahrenheit. Richardson's group engineered a solution using an optical device called a borescope and video camera that could withstand the low temperatures and high pressures to visualize what was going on within the test chamber.
"Those aren't the friendliest conditions," he said. "You have to come up with creative solutions."
The researchers succeeded and took video footage of ethane-methane rain and snow. The group also studied the freezing temperatures for methane and ethane lakes and determined that, because of a small amount of nitrogen in the liquid, the lakes freeze at lower temperatures than would be expected: 75 Kelvin, or -324 degrees Fahrenheit, instead of 90.5 Kelvin.
"That's a big deal,'' said Richardson. "That means you don't have to worry about icebergs."
The researchers are looking to continue the work with NASA to update the Titan Submarine design.
Jake Leachman | EurekAlert!
Temperature-controlled fiber-optic light source with liquid core
20.06.2018 | Leibniz-Institut für Photonische Technologien e. V.
New material for splitting water
19.06.2018 | American Institute of Physics
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences
20.06.2018 | Materials Sciences