# A conceptual submarine mission to explore Titan. **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [February 16, 2015, 10:48pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865 "2015-02-16T22:48:43Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 16, 2015, 10:48pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/1 "2015-02-16T22:48:43Z")
This is cool. > **[This Is The Submarine NASA’s Wants To Use To Explore Titan](https://www.iflscience.com/check-out-nasa-s-conceptual-submarine-explore-titan-s-kraken-mare-27253)** > > This Is The Submarine NASA’s Wants To Use To Explore Titan > [@](#): > > 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. > … > 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. There’s a more technical paper on it here: > **[1259.pdf](https://www.hou.usra.edu/meetings/lpsc2015/pdf/1259.pdf)** > > 164.45 KB I love this idea. Is it viable? ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 16, 2015, 11:09pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/2 "2015-02-16T23:09:03Z")
It seems a bit limited - I’d send a dirigible so it could go anywhere - except under-ethane. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 16, 2015, 11:41pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/3 "2015-02-16T23:41:50Z")
> [@Quartz](#): > > It seems a bit limited - I’d send a dirigible so it could go anywhere - except under-ethane. I think that misses the point. The most interesting part of Titan, and the part most likely to harbor life, is the seas. You could send both a submersible and a dirigible I suppose, except I’m not sure if Titan has enough of an atmosphere for a dirigible. ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [February 17, 2015, 5:59am UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/4 "2015-02-17T05:59:40Z")
Titan has [more of an atmosphere than Earth](http://saturn.jpl.nasa.gov/science/index.cfm?SciencePageID=75): > [@](#): > > Because Titan is less massive than Earth, its gravity doesn’t hold onto its gaseous envelope as tightly, so the atmosphere extends to an altitude 10 times higher than Earth’s – nearly 600 kilometers (370 miles) into space. In 1980 the Voyager 1 spacecraft showed that the air pressure at the surface is one-and-a-half times that of Earth at sea level and four times the density, but the surface temperature is extremely cold, at -290 degrees Fahrenheit (-179 degrees Celsius). But yes, a Titanian submarine would be an amazingly cool mission\*. Also, Kraken Mare is a totally badass name for an alien methane sea. \*No pun intended, despite the -290 Fahrenheit surface temperature. ---
**Author:** ![Ale](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@Ale](https://boards.straightdope.com/u/Ale)\ **Post date:** [February 17, 2015, 1:28pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/5 "2015-02-17T13:28:15Z")
Doesn’t seem viable to me, way too complicated, costly and very likely to fail. Perhaps a buoy or propelled boat type of probe, with a tethered ROV or simple [bathysphere](http://en.wikipedia.org/wiki/Bathysphere) would be more feasible. After that if the seas prove to be navigable by a submarine then, by all means, anchors aweigh. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 17, 2015, 2:37pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/6 "2015-02-17T14:37:29Z")
I have to wonder about testing. How similar to water would liquid methane be? We could do tests in water here, but would it be possible to create some sort of test pool of liquid methane in a sealed chamber? Would it be necessary to do so? Fire would be an obvious concern in working with liquid methane. Is there some non-flammable liquid that’s similar enough to methane that it could be used for testing? Of course, NASA also can’t exactly replicate conditions on the Moon or Mars but they’ve managed to design equipment that worked in both of those environments. ---
**Author:** ![Ale](https://avatars.discourse-cdn.com/v4/letter/a/f19dbf/32.png) [@Ale](https://boards.straightdope.com/u/Ale)\ **Post date:** [February 17, 2015, 6:28pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/7 "2015-02-17T18:28:57Z")
> [@davidm](#): > > I have to wonder about testing. How similar to water would liquid methane be? We could do tests in water here, but would it be possible to create some sort of test pool of liquid methane in a sealed chamber? Would it be necessary to do so? > > Fire would be an obvious concern in working with liquid methane. Is there some non-flammable liquid that’s similar enough to methane that it could be used for testing? > > Of course, NASA also can’t exactly replicate conditions on the Moon or Mars but they’ve managed to design equipment that worked in both of those environments. One big honking problem of diving in liquid methane is that it’s at, IIRC, -170C or so; but electronics and specially batteries don’t work well at those temperatures so the submarine would inevitably be much hotter than the surrounding liquid, making it boil around it which in turn would make buoyancy control very iffy, not to mention how it would affect sensors. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [February 17, 2015, 6:44pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/8 "2015-02-17T18:44:12Z")
> [@Ale](#): > > One big honking problem of diving in liquid methane is that it’s at, IIRC, -170C or so; but electronics and specially batteries don’t work well at those temperatures so the submarine would inevitably be much hotter than the surrounding liquid, making it boil around it which in turn would make buoyancy control very iffy, not to mention how it would affect sensors. The question would be whether they could insulate it enough that the liquid around it wouldn’t boil. Presumably a propeller would need to be powered by induction so the hull wouldn’t have to have a hole for the drive shaft. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 17, 2015, 8:03pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/9 "2015-02-17T20:03:36Z")
> [@Boyo\_Jim](#): > > The question would be whether they could insulate it enough that the liquid around it wouldn’t boil. Presumably a propeller would need to be powered by induction so the hull wouldn’t have to have a hole for the drive shaft. You’d presumably also need exposed sensors. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [February 17, 2015, 9:47pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/10 "2015-02-17T21:47:52Z")
And exposed rudder and vanes. Possibly an exposed buoyancy system too. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [February 17, 2015, 10:47pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/11 "2015-02-17T22:47:41Z")
> [@Boyo\_Jim](#): > > The question would be whether they could insulate it enough that the liquid around it wouldn’t boil. Presumably a propeller would need to be powered by induction so the hull wouldn’t have to have a hole for the drive shaft. Better: have materials, electronics, motors, lubricants, etc, that can all work at Titan temperatures. (Has work on this been done?) What if we had a heavily-insulated boat that would float and support the main heat sources like the computer and the radio-isotope generator, as well as things that need to see the sky, like the antennas, and it was supporting a cold bathyscaphe with low-temp cameras and sensors? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 17, 2015, 11:43pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/12 "2015-02-17T23:43:07Z")
At least some of the electronics in the Voyager probes are still working and they’re a long long way from the Sun where I assume it’s at least as cold as the Titanian methane. Although they may be heated by their nuclear power source. Also the liquid methane would conduct heat better than vacuum would. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [February 18, 2015, 12:00am UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/13 "2015-02-18T00:00:08Z")
> [@Sunspace](#): > > Better: have materials, electronics, motors, lubricants, etc, that can all work at Titan temperatures. (Has work on this been done?)… Presumably, as we have sent stuff that far out before. One concern I did have was that maybe being exposed to an atmosphere at the same time as cold could have a different effect than just being out in the vastness of [space](https://www.youtube.com/watch?v=MAW2lygZC_4). Since we’ve sent robots to Mars, where there is an atmosphere and where it is typically colder than Earth, I presume that some thought had gone in to making sure stuff was going to work. Whether that’s enough for Titan, I’m not sure. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 18, 2015, 2:50am UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/14 "2015-02-18T02:50:36Z")
We have sent stuff that far and farther; but liquid methane is going to conduct heat much more efficiently than the vacuum of space so it’s a different situation. Even if you can design it to work at the ambient temperature, **Ale** ’s concern regarding the methane around it boiling is still pertinent because electronic and electromechanical components will give off heat and there’s no place to dump that heat other than the surrounding methane. ---
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [February 18, 2015, 4:06am UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/15 "2015-02-18T04:06:49Z")
Titan is a mother lode of hydrocarbons. Too bad it’s so far away. Or maybe that’s a good thing, actually. Parts of [Ligeia Mare](http://en.wikipedia.org/wiki/Ligeia_Mare) are 170 meters deep. If it was filled with microscopic life wouldn’t it be scuzzy instead of so clear? The problem with life on the surface is that it’s so cold. Seems more likely for life to be in the [subsurface water ocean.](http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20120628.html) Hard to get to that though. Maybe a drill? I’m still waiting for my Europa cryo-submarine / cracking the shell with multiple nukes and dropping a buoy down the melted hole. For science. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [February 18, 2015, 1:41pm UTC](https://boards.straightdope.com/t/a-conceptual-submarine-mission-to-explore-titan/712865/16 "2015-02-18T13:41:58Z")
Wikipedia has articles about two proposed lake exploration missions. Both would be surface vessels rather than submersibles. One of them would just float around on the surface unpropelled: [Titan Mare Explorer - Wikipedia](http://en.wikipedia.org/wiki/Titan_Mare_Explorer) The other would be propelled: [Titan Lake In-situ Sampling Propelled Explorer - Wikipedia](http://en.wikipedia.org/wiki/Titan_Lake_In-situ_Sampling_Propelled_Explorer)