"Permafrost is like concrete."
"It blunts jackhammers, it laughs at blowtorches. A nuclear detonation or meteor impact will rapidly find hard bottom and be repelled back out as a shock wave."
That being so, what's the plan for that arm and bucket, with precious little leverage, to be able to dig through it? I'm sure there is one, I just can't imagine what it might be.
Arf