
The $1 billion mission to reach the Earth's mantle - ssclafani
http://edition.cnn.com/2012/10/01/tech/mantle-earth-drill-mission/index.html?c=&page=1
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anonymouz
Contrary to the claim of the article, $1 billion to get samples from the
Earth's mantle does not sound particularly expensive.

Especially if compared to all the other things that we nowadays spend billions
on, and where the long-term benefit is much less clear.

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CountHackulus
Considering that the unit cost for a B2 bomber was $737M (a little over $1B
with inflation), I'd say that this is a steal. Just think of things in recent
days that have reached the $1B level. For this kind of science? I'd say we'd
be stupid NOT to pay for it.

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tjmc
Agreed. Learning how to drill to effectively unlimited geothermal power
reservoirs can't be a bad thing.

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jerf
We don't fail to drill more geothermals because we are incapable of it, we
don't do it because the cost/benefit ratio isn't favorable in most places.
Since this isn't about advancing technology, but applying what we already have
to this task, this project isn't going to change that.

There's all kinds of things that are possible, but not profitable. And
especially when it comes to energy, "profitable" isn't just about money;
putting in 2 Joules to create the ability to generate 1 isn't economically
practical any more than a company that burns 2 dollars to make 1 is.

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habosa
"It will be the equivalent of dangling a steel string the width of a human
hair in the deep end of a swimming pool and inserting it into a thimble 1/10
mm wide on the bottom, and then drilling a few meters into the foundations"

Wow, that quote really put it all into perspective for me.

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jofer
And to put it in even more prespective, we're just talking about drilling
through the equivalent of the skin of an apple.

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ChuckMcM
I remember as a kid some of the conspiracy theories about how the US cut off
and then classified all the deep drilling work in the late 60's [1]. I had a
chance early on in the 80's to invest in a company that had designed a new
drill head (one of my USC alums went to work there), I thought it was a silly
investment I mean drill bits? really? But they did quite well with it.

That said, the whole concept of just digging and digging until you hit the
middle holds childlike fascination for me.

[1] Mostly related to discovering alien artifacts and the like.

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zem
i'm really excited about the medium-term promise of abundant geothermal energy

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ChuckMcM
As am I although there is pretty damning evidence in Sonoma County [1]
California that you can cause earthquakes with it. That said, I'm surprised
we've not seen more closed loop systems [2][3]. My favorite is to take a loop
of tungsten tubing a reservoir, a cooling tower, and a turbo pump and toss the
tubing into the magma flow of a volcano. Pull out enough heat to run a turbine
but not much that you freeze the lava. I'm totally going for this concept in
my Mad Scientist Power Base.

[1] <http://www.geysers.com/>

[2] <http://www1.eere.energy.gov/geothermal/powerplants.html>

[3] <http://www.atlanticgeothermal.com/about/what-we-do.html>

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robomartin
I'll admit to being utterly ignorant about deep-hole drilling. If I was tasked
with doing something like that I'd do two things:

1- I would not do it in the ocean

Lots of reasons, from the potential to damage an ecosystem to the unknowns
that could be catastrophic in so many ways. Of course, cost is another reason.

Doing anything in the ocean --particularly deep-- is incredibly difficult and
expensive.

2- I would not use a ten mile long shaft with a drill at the end of it.

I just don't think that this is the way to do it. Again, I am ignorant when it
comes to drilling of this sort.

What I would do would be to design a drilling robot that would drill the hole
and burrow itself down the hole as it works. To continue with the overly
simplistic view, the only thing this robot would need would be power (lots of
it).

You select a candidate site and build a large solar array, large enough to
power the drill-bot.

A starter hole of the required depth and diameter would be drilled via
conventional means. The robot would then be inserted into it. It would expand
and clamp itself to the hole to begin drilling deeper. If the broken-up dirt
and rocks must be removed either the robo-drill has the capability to collect
some amount of it and traverse back to the surface or it comes back and a
"cleanup" robot would go down to get the stuff out.

It'll take a long time? Is that a problem? The operation could probably have a
good degree of automation.

Probably a horrible idea. Don't know.

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jofer
Just for the sake of explanation, here are some of the reasons (I'm a
geophysist, currently working in the oil industry, but my dissertation work
relied heavily on the Chikyu (the ship in question)):

1: The ocean is the only place where it's feasible. The continents have much,
much thicker crust (40-70km) than the ocean basins (7-15km). Areas of exposed
oceanic crust (e.g. Iceland) have much thicker than normal oceanic crust.

Beyond that, it's (slightly) easier to "drill" through water than through
rock. There are a still a _lot_ of challenges involved in deep-water riser
drilling. You don't just have a what's basically a steel rod going down (as
you would with riserless drilling), you have to have a system that's capable
of returning fluids and maintaining high pressure going all the way down to
the seafloor (and below, once you case the well). However, it's still faster
to deploy the riser than it is to drill through solid rock. At any rate, I'm
getting sidetracked. The locations where they're looking to drill to the moho
are in relatively shallow water (3-4 km) compared to the water depths that the
Chikyu has already drilled in.

2: You're misunderstanding how drilling works. :) In some sense, what you've
described is exactly how it works. (Just think of the drillbit as the robot.)
However, you have to overcome the pressures at the depth you're drilling at
(otherwise the hole will collapse, among other things) and you need an
efficient way to return the cuttings (waste material) to the surface. Thus:
drilling mud. You circulate pressurized (and very dense, so that the pressure
increases with depth) fluid that flushes the cuttings back to the surface and
keeps the borehole open. (It's an oversimplification, but that's the basic
idea.) In some cases (e.g. coil tubing rigs), this fluid is even what drives
the drillbit.

At any rate, hopefully that helps illuminate things a touch. :)

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robomartin
My disclaimer was accurate: I am ignorant about these things. I going camping
this weekend. Can't think of a better subject to Google while out there (gotta
love coverage in California) and learn about.

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jofer
Isn't googling while camping cheating? :) While you're at it, look up the
Chikyu. It's a very neat ship! (and some of the translations on the JAMSTEC
website for the Chikyu are amusing: e.g. "Science the Earth")

That aside, they're very good and very reasonable questions.

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petenixey
What happens when you hit the mantle? Does the rock come out or solidify in
the pipe, how does the drill cope with the heat?

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brentm
pretty sure no one has any real idea only theories. hopefully it doesn't start
some crazy volcano that eventually engulfs everything. when this planet does
go the way of the buffalo it likely will be our own fault.

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sharkweek
I was secretly hoping for that Russian drill team in the arctic tapping into
that frozen lake to unleash some sort of crazy frozen, earth-destroying
demon/alien

Perhaps I will shift my wishes to this mantle quest to unlease some fiery,
earth-destroying demon/alien.

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anonymfus
You will like this Doctor Who episode if you didn't see it yet:

<http://en.wikipedia.org/wiki/Inferno_(Doctor_Who)>

~~~
nnnnni
The first thing that came to mind was this one:
[http://tvtropes.org/pmwiki/pmwiki.php/Recap/DoctorWhoS31E08T...](http://tvtropes.org/pmwiki/pmwiki.php/Recap/DoctorWhoS31E08TheHungryEarth)

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mparlane
Reminds me of:

<http://en.wikipedia.org/wiki/Kola_Superdeep_Borehole>

"Because Russia"

~~~
archon
"Because science isn't always cheap and doesn't always produce immediately
obvious benefits."

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aik
If the hole is only 30cm wide, and it's going to take 8 years to complete
(complete in 2020), isn't there a decent chance that there will be movement in
the plates that will close up the hole?

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hollerith
If they take care not to drill through any faults, which I expect they will,
then the whole hole will move as one.

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fleitz
Only 10 times the cost of making a movie about reaching the core.

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BklynJay
Who else is expecting the chief scientist on the project to say: "What could
possibly go wrong?" :)

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dclowd9901
> It will be the equivalent of dangling a steel string the width of a human
> hair in the deep end of a swimming pool and inserting it into a thimble 1/10
> mm wide

Can someone clean up this horrible analogy?

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grannyg00se
How about....dangling piano wire from a twenty story highrise rooftop down
into a test tube.

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gajomi
>"It will be the equivalent of dangling a steel string the width of a human
hair in the deep end of a swimming pool and inserting it into a thimble 1/10
mm wide on the bottom, and then drilling a few meters into the foundations,"
says Teagle.

If this is indeed an accurate analogy than I would be very interested to see
it done as a proof of concept!

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pizu
Why not probe samples from a volcano, instead ???

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techas
Because the rocks extruded in a volcano suffer a lot of changes during its way
up. Moreover, a mantle rock is composed by many different minerals. When
temperature goes up, some minerals melt first. So, you expect the extruded
magmas to be enriched in those minerals. The extruded rocks are not sampling
the mantle properly. Of course they provide tons of information, but is not
the same as having a fresh mantle rock.

~~~
s_baby
Also the possibility of finding new life forms. We've found life drilling
several miles down. How much further does it go?

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hammock
My first thought (before reading) was that this was a commercial mining
operation, in the vein of asteroid mining missions, etc.

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Angelo8000
What are you going to do once you get there?

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samspot
I'm ok with it as long as Gordon Freeman isn't involved.

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songzme
What is the earth explodes? Earth was designed to keep the very hot stuff
inside a very hard container. If we break this container by drilling through
it, the hot stuff will explode and humanity will get hurt.

