Encleadian Ocean Likely!

[Halsfury]

why not drill down as far as you can right next to a plume, and then drill over to the side and use the force of the plume to shoot the probe into a sub orbital trajectory and transmit in space.

It could be controlled with a gyroscope if you had a base probe which could do some survey work at the surface and determine a course before letting it drill. and you don't have to worry about cables when you have a transmission oppertunity after the thing gets shot back into space

[Motokid600]

why not drill down as far as you can right next to a plume, and then drill over to the side and use the force of the plume to shoot the probe into a sub orbital trajectory and transmit in space.

It could be controlled with a gyroscope if you had a base probe which could do some survey work at the surface and determine a course before letting it drill. and you don't have to worry about cables when you have a transmission oppertunity after the thing gets shot back into space

Too many variables. The probe would most likely be destroyed. No, imo my idea is the simplest solution to the transmission issue. Just.. climb back up the hole.

[Kryten]

At those depths, there wouldn't be a hole to climb up. Ice is a lot more plastic than rock, it would just slump in on itself.

[vger]

Too many variables. The probe would most likely be destroyed. No, imo my idea is the simplest solution to the transmission issue. Just.. climb back up the hole.

I'm skeptical enough about a probe having enough power to drill (or melt) its way 40km down. Going back up is going to be even worse. IF it can reach the ocean, I think it's safe to assume that it's going to stay there. And any transmissions are going to have to be wireless.

And...

Gosh I wish this kind of functionality existed in KSP, with mission problems so intricate that they could have us all debating possible solutions.

[Stargate525]

Gosh I wish this kind of functionality existed in KSP, with mission problems so intricate that they could have us all debating possible solutions.

Agreed!

...Got it! We drill down as far as the power lasts, then use an onboard thermonuclear weapon to detonate a giant hole. Orbital satellite collects data when it passes over!

[Scotius]

Or drill-probe could leave small relay stations behind. They would act as signal amplifiers. Of course we'd have to find how far signals can travel through ice, then figure out how to build such station small enough to take enough onboard, but still able to do its job. Without being crushed by ice Maybe probe could have 3D printer onboard, and filter necessary materials out of melted water? Then there would be no need to pack dozens of comm buoys - they would be made on the go.

[vger]

We drill down as far as the power lasts, then use an onboard thermonuclear weapon to detonate a giant hole. Orbital satellite collects data when it passes over!

But wait, something still has to go down and collect a direct sample. We can already get the same results from the nuclear explosion by having a probe pass through the plumes.

Oh, nevermind. Jeb can just go down with the probe and collect a sample after it blows up.

[Rainbowtrout]

Personally, I believe that some tests should be ran on the Encleadian Ice, such as the effectiveness of explosives in getting to the ocean, and possibly bring some ice back for study.

[magnemoe]

In another direction, is it water only around the south pole? it look so in the image, if so, why?

[Idobox]

Seriously, sounds travel very well through ice, and 40km is nothing, forget cables, IR and radio and settle for a few kilobauds. You will need some sonar anyway.

A small probe with an RTG would just have to sit and wait to sink to the the bottom in a few months. Let's do back of the envelope math:

Let's picture a 1m radius, 40km high cylinder of ice at 75K and 1 atm. The thing would weigh 1.1e8kg. To bring it to 275K and melt it, you would need 7e13J.

The RTG of curiosity provides 2kW thermal, so it would take it about 1000 years (in practice much more, since its power decays)

If you want to melt through that ice, you'll need something significantly more powerful, or something much smaller.

[TheGatesofLogic]

umm, why was a tethering cable dismissed? lander probe carries sinker probe in its undercarriage and releases it onto the icy with a long thin tether held in the larger hub-probe, this is not a ridiculous length of cord and is in fact quite reasonable under the expected conditions. Overall it is a difficult but feasible idea. worst case scenario the tether must have several deployable hubs which lower tether drag.

[Drunken Hobo]

Maybe we don't need to send anything 40km into the subsurface ocean. Why not just land a rover next to an active cryovolcano, and take samples from there?

[magnemoe]

Maybe we don't need to send anything 40km into the subsurface ocean. Why not just land a rover next to an active cryovolcano, and take samples from there?

This, even simpler use an stardust style capture device in an flyby or orbit but yes samples from outside an volcano will show a lot more,

[Idobox]

This, even simpler use an stardust style capture device in an flyby or orbit but yes samples from outside an volcano will show a lot more,

That would be great, but yield much less information than a submarine probe.

If life concentrates on the bottom of the 10km deep ocean (likely if it feeds on black smokers), there is no assurance it can be detected in top water ejected at high speed through an ice pipe.

umm, why was a tethering cable dismissed? lander probe carries sinker probe in its undercarriage and releases it onto the icy with a long thin tether held in the larger hub-probe, this is not a ridiculous length of cord and is in fact quite reasonable under the expected conditions. Overall it is a difficult but feasible idea. worst case scenario the tether must have several deployable hubs which lower tether drag.

You can't put the reel on the surface if you melt your way through, the cable will be stuck in ice after a few meters. If you drill, it will be stuck after a few km because the borehole will collapse under the pressure.

If the ice is not stable, the cable could be easily ruptured by the equivalent of tectonic movements, and if you want to keep it light, you can't use it for power, just communication, while there are easier ways to transmit data.

[jfull]

Its still possible that using a cable would not be out of the question.

In theory, a very thin fiber optic cable could have the necessary length with much less weight than you might expect. Obviously though, this means that it would be susceptible to breaking.

Maybe there could be at least 2 cables for redundancy

[DerpenWolf]

You could use an exposed and semi excited yet controlled uranium nose or something similar to melt through the ice while an rtg powers the spacecraft. If you really want to come to the surface you could loose some weight (maybe drop some instruments?) and fill a few pouches with air so you are pushed towards the surface?

[SuperFastJellyfish]

I am very math challenged these days, but I'm wondering how high up the drill hole(assuming it wouldn't collapse first) would the pressure of 40km of ice push the water after you break through to the ocean? Would it become a geyser or would it level off at x distance up the hole?

[-Velocity-]

I am very math challenged these days, but I'm wondering how high up the drill hole(assuming it wouldn't collapse first) would the pressure of 40km of ice push the water after you break through to the ocean? Would it become a geyser or would it level off at x distance up the hole?

Wouldn't the hole freeze back in behind you? You're not actually drilling a hole and removing the material off to the side; you're melting your way through, and leaving a cable behind you. So your question would be moot.

That said, if you removed the ice and left an actual drill hole, I believe the answer to your question would be that the pressure at the bottom of the hole needs to equal the pressure of the sea you're drilling into. Well, that much is obvious. So, to equalize the pressure, I believe that the ratio between the length of the hole that is flooded vs. the total length of the hole will equal the ratio of the density of ice over the density of water.

So, if the hole is 40 km deep and ice is 0.8 times as dense as the ocean water, then the water will only rise up 0.8*40 km = 32 km- stopping 8 km short of the surface.

A simple way to visualize why I think this is the correct answer is to imagine a straight sided hole of uniform width. To equalize the pressure, the weight of the water filling the hole must equal the weight of the ice that was removed to make the hole in the first place.

I think. Someone who is more familiar with fluid dynamics correct me if I am wrong.

Edited April 8, 2014 by |Velocity|

[ZedNova]

Wouldn't the water under the ice shoot the probe up when you break through?

[-Velocity-]

Wouldn't the water under the ice shoot the probe up when you break through?

Yes, if was ACTUALLY drilling, but no, because in REALITY a melt-probe melts its way through, and there is no hole because the hole gets filled in behind it with re-frozen water. So there is nothing to "shoot" the probe up into.

[vger]

Maybe this is all being looked at in a much too complicated fashion. It was said that the dark bands of the moon are leftover from fissures that have previously erupted. If that's true, then isn't it possible that after an 'eruption' an open crevasse is left behind? It might be possible to drop a probe down one before it has a chance to close up.

[Idobox]

You could use an exposed and semi excited yet controlled uranium nose or something similar to melt through the ice while an rtg powers the spacecraft. If you really want to come to the surface you could loose some weight (maybe drop some instruments?) and fill a few pouches with air so you are pushed towards the surface?

As I showed, a curiosity sized RTG is grossly underpowered. What could do the job would be an actual nuclear. The phase 3 of NERVA demonstrated 4000MW, this thing would melt through the crust in months, and it would make a great interplanetary stage, or even a landing stage.

Go go nuclear rockets!

[vger]

As I showed, a curiosity sized RTG is grossly underpowered. What could do the job would be an actual nuclear. The phase 3 of NERVA demonstrated 4000MW, this thing would melt through the crust in months, and it would make a great interplanetary stage, or even a landing stage.Go go nuclear rockets!

Yeah, if only we could do it without causing a global panic in the process, as the propaganda wheels start spinning, turning a scientific expedition into a secret plan to nuke a country and get away with it.

[Kryten]

Just like what happened last time NASA launched a nuclear reactor into space. Get a grip, the majority people are about as likely to seriously believe any launch containing nuclear material is a secret plot as they were to get behind the astrologer who sued NASA over deep impact.

[Exoscientist]

Aha, well 200m depth is certainly a lot more reasonable than 40km.

Curious question about glaciers though, are fissures so common that you could land pretty much anywhere and find one so shallow?

If this model of the tiger stripes is correct, it might be possible to travel through them directly to the ocean below:

This NASA page also shows a model of the plumes that connects a vent at the surface to an ocean below:

This graphic shows how the ice particles and water vapor observed spewing from geysers on Saturn's moon Enceladus may be related to liquid water beneath the surface. The large number of ice particles and the rate at which they are produced require high temperatures, close to the melting point of water. These warm temperatures indicate that there may be an internal lake of liquid water at or near the moon's south pole, where the geysers are present.

http://www.nasa.gov/mission_pages/cassini/multimedia/cassini20080207.html

In this model the temperatures don't have to be particularly high, just near the melting point.

Bob Clark