How to extract an object from 200 miles below the surface of the planet Mercury?

In Stephen Baxter's science fiction Novel Ultima humans discover mysterious "kernels" which allow high speed space propulsion units to be built. The problem is that these kernels are only to be found 200 miles below the surface of Mercury.

How (in outline) could these kernels be plausibly retrieved from such a great depth in such an environment?

I assume that this is not currently possible with today's technology, but what challenges would be faced and how might they be overcome using near future technology? Indeed is this even remotely possible?

Assume the active engagement of governments and a virtually unlimited budget. The kernels are 0.5 meter spheres of density similar to the material that surrounds them. They are very tough but might be destroyed by nuclear weapons. Assume that their existence and approximate location are already known.

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The idea is for answers to explore the technical possibilities rather than the financial limitations. However financial limitations are a valid concern, so for those who have asked for clarification on what constitutes a "virtually unlimited budget" let's say $100 billion a year for twenty years, with options for spreading the cost over twice as long if necessary. No quibbling "“ the politicians have somehow agreed to it (gasp) because the possibilities of the new drive will be so revolutionary.

posted about 7 years ago

Slarty‭

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