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Unmanned Autonomous Earth Probe

Instead of digging into earth send an unmanned probe
  [vote for,

It doesn't have to be too big.
It doesn't have to send the "dirt" up to the surface. It has to be able to work under extreme pressure. It needs to be able to move constantly downward. It needs to be able to probe and discover the materials and conditions it is in, and it should be able to communicate the results (by sound?) It must work in extreme heat (lava), and in both dry and wet (mud) conditions.

We may not be able to penetrate earth that much, but more than the current 12 km (by the Russians, going vertically into an ancient lopsided layered crust, instead of directly down) is very "probable". Don't you think?

Does anybody know how thick the crust is at the Dead Sea?

pashute, Aug 30 2009

And I don't mean using a nuclear crack http://news.nationa...0514_earthcore.html
Scientist proposes nuclear power to create a deep crack for an earth probe [pashute, Aug 30 2009]

Terra hammer http://www.usae.com...d-terra-hammer.html
earth boring tool [csea, Aug 30 2009]

Project Mohole http://en.wikipedia...wiki/Project_Mohole
prior art [csea, Aug 30 2009]

Rapid Excavation by Rock Melting http://www.osti.gov...-0OvFBP/4342957.pdf
LASL Subterrene project [csea, Aug 30 2009]

Dead sea geology and seismic test results... http://www.scienced...4c87d3b7ba837af31f7
How much would you pay to know them, But WAIT, there's more. [2 fries shy of a happy meal, Aug 30 2009]

Crustal Thickness of the Arabian Plate http://www.meseisfo...l_arabian_plate.pdf
Here's some info [lurch, Aug 30 2009]

Kedunbengo - Now I no why not in wikipedia http://www.eurotrib...006/10/6/94211/9832
After reading this, and previous link (Lusi, by [UnaB]) [pashute, Sep 02 2009]

Arthur C Clark October 1945 http://lakdiva.org/...ww_oct_305-308.html
Here he already acknowledges rockets and even stage rockets, but believes atomic propulsion will be the solution [pashute, Sep 14 2009]

Arthur C Clark 2001 http://www.arthurcclarke.net/?scifi=3
In retrospect, mentions no problem in predicting rocket propulsion [pashute, Sep 14 2009]


       The problem with the crack idea (see link) is that there's mud and lava deep down, so it would fill up! What's with these scientists? Don't they have any imagination?
pashute, Aug 30 2009

       //The problem with the crack idea (see link) is that there's mud and lava deep down, so it would fill up//
That's what the 10^8 kg of molten iron is for.
What's up with these halfbakers?
Don't they read?
AbsintheWithoutLeave, Aug 30 2009

       The Dead Sea Basin appears to be a "pull-apart" zone, so it does have some crustal thinning, but it's also very old and contains deep sediment strata. And the thinning is relative to it being in a very thick part of the Arabian plate. Per the link, you might have better luck farther south in the Red Sea area. Or even around the Horn of Africa, between Yemen and Somalia. (If the pirates don't come and steal your hole.)
lurch, Aug 30 2009

       Drop it in a shield volcano, like Mauna Loa. It will need to have enough speed to move against the upwelling lava.   

       It's going to have to withstand 1000 C or more indefinitely and still function. That's quite an engineering challenge. A tungsten casing would withstand 3000 C but you'd better have some good insulation inside.......
8th of 7, Aug 30 2009

       So the idea is a probe, for the earth. Could you elaborate beyond vague specs? Especially, why do you believe a probe is superior to drilling (think of the drill bit as a rather dumb probe that is provided with power via a rather fat mechanical umbilical)?
loonquawl, Sep 01 2009

       >Especially, why... probe is superior to drilling...
Because when drilling, you have to bring the dirt all the way up, and keep the "line" free of earth or molten iron.

       >Tungsten casing... good insulation...
1. Insulation is possible by creating a tungsten foam material. 2. I'm not sure insulation is needed. A machine of this type could be engineered to work ABOVE 1000c. Its not impossible. It could be built of "stages", the first stage a conventional "digger" motor, (unless from the beginning its a lava swimmer as [8th] suggested, and when reaches those heats, uses materials that withstand, and "fuel" that turns to gas only above those temperatures, so that you can perhaps even use the extensive heat to propel the probe further down.

       [UnaBubba] hmm... What if we're talking of an ant sized probe. What damage could that do?
(I can see this quoted on CNN, a day after NASA scientists who made the probe according to HB specifications revealed that the disappearance of half the ocean waters in the past month is due to a tiny probe that opened a connection to a giant vacant cave 15.5 km under earth's crust. But then it would be good to know about it and take care of it technologically rather than find out due to an earthquake 10,000 years from now. No?
Why is their no (and was no) Wikipedia article on Kedungbendo?

       OK, off to see the links...
pashute, Sep 02 2009

       Er, how is speedy molten iron falling into a crack and cutting a fast hole into earth going to stop the tunnel in back of the grapefruit probe from filling up. (Of course it will work, and they obviously will have a communications unit on the grapefruit, that doesn't need air in the crack), but actually it sounds like a violent solution, for something that needs a gentle one. I remember reading a scientific book (non fiction) by Asimov saying that before the lunar missions, Sir Arthur C Clark had said that to reach the moon we would need a rocket with explosives so violent that they would shatter earth. It turns out we used enough only to make a small hole in the ozone layer.
pashute, Sep 02 2009

       Hasn't anyone considered that the best place to insert this thing would be a submarine volcano in a mid-oceanic rift or maybe a trench?
nineteenthly, Sep 02 2009

       //Sir Arthur C Clark had said that to reach the moon we would need a rocket with explosives so violent that they would shatter earth.//
That sounds very unlikely.
Clarke was an exceptional engineer (he proposed geostationary satellites in the late 1940s), and wrote that much earlier critics of space travel (around the time of Tsiolkovsky) had said that even the most violent of explosives available would be insufficient to achieve even Earth orbit.
Clarke pointed out that energy, not violence was what was required.
coprocephalous, Sep 02 2009

       I'm still not convinced this is an idea.   

       Beyond saying what it has to be capable of withstanding/operating in, and that it has to //move constantly downward//, you give no clue as to why the probe should be able to do what usually takes huge force, 'gently'.   

       A sun probe, for instance would have to be able to withstand incredible temperatures, pressures, and electro-magnetic forces, and would have to move towards the sun...
loonquawl, Sep 02 2009

       Obtanium. And here's why:
IMHO there are five basic challenges, under 3 constraints.
Challenges: 0. Materials 1. Motion. 2. Power. 3. Control 4. Communications.
Constraints: 1. High temperature. 2. High pressure. 3. Long distance (depth)

       It's important to make it clear that I DO NOT think we will reach all the way to the center of earth, but I'm sure we can do better than the current (doubtful) 12 km.   

       So lets look into the solution needed:
0. Materials: Deciding on the materials is a precondition for this project. Fortunately, there definitely ARE materials that will not melt at these temperatures, and will not loose their shape because of temperature. (I'm not saying that all materials would be cheap). The high temperature will affect the choice of power supply - we'll discuss that soon. Pressure may not be an issue (for the materials), because if there is no gas involved, it should be counter balanced. In other words the probe will itself be "molded" into one solid peace. I believe pressures like this can be reached and tested on earth's surface.

       1. Motion: This is divided in two: a. Propulsion, b. Motor. We'll deal with the motor when we talk about the Power challenge. If its movement in a liquid, (molten rock) we need only a propeller made of the above said <b>obtainable</b> materials connected to a motor. If its some sort of rock or sand that we are discussing (and as far as I understand its some sort of boiling mud) then a different mechanism is needed. But such mechanisms exist. I saw the giant German machines we took from the PLO in 1982 that were used to make bunkers in the Bufore Fort in Lebanon. They make all the road tunnels in Israel, and we have quite a few now. Same type of machines made the tunnels under the Suez canal in 1983 for Egypt. (See Tera Hammer Link on tiny machine of sorts by [c5ea]). And please don't forget that this probe could be built of stages, where propulsion of one kind can be replaced by another, under different conditions.   

       2. Power: This will have to be an innovative way of releasing and harnessing energy. Perhaps even using the earth's heat to power this machine. Here on the surface, we usually use combustion, which is controlled because the fuel does not burn until induced to do so. So in comparison, we would need some kind of fuel that does not burn at such temperatures, unless some trigger is given. Again this is obtainable, if you remember that at such high temperatures you could use the external heat to act on a material that is ready for combustion. Then, there is a whole set of alternatives to combustion. The most obvious is harnessing the heat of the underworld itself. What happens to solid nitrogen under such pressures, when it receives heat at those temperatures. Surely a jet effect would be achieved (of at least liquid nitrogen if not gas). Or using the power of dimetals. And I will not mention the obvious alternative, but one which I avoiding as best I can. I also would not write off the possibility of using the immense heat to create cooled points, and then use the heat flow at will.   

       3. Control: Of course electric control is the immediate idea that comes to mind. That is definitely obtainable. There are conductive and non-conductive materials that can withstand these conditions of heat and pressure. So you wont be using off-the-shelf electronics, that's true. Electric energy can be stored in many ways, besides the batteries we are accustomed to, just read about molten salt batteries as an example. And electricity itself is not the sole candidate for control. Ever since the end of the 19th century there have been countless mechanic inventions, sufficient to build a well designed self propelled probe.   

       4. Communication: If the probes are built in stages, they could also launch back probes to communicate back to the surface. Or they could use electronics. I already showed that it is definitely conceivable to possibly build a deep earth probe working electronically.   

       To summarize: It is highly conceivable that a probe like this can be built from obtainable materials.   

       About Arthur C Clark: I think the book was Quasar Quasar burning bright. I'll look it up.
pashute, Sep 14 2009

       Arthur C Clark... see link
pashute, Sep 14 2009

       //I also would not write off the possibility of using the immense heat to create cooled points, and then use the heat flow at will.//   

       That's the way to flip ol' Thermodynamics the bird!
lurch, Sep 14 2009


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