Astronomy

Too heavy. :p

Drilling slowly through ice with heat isn't a very spectacular claim, at any rate. You'd need to keep the descending arm heated too I suppose, otherwise it'd all get stuck as it refroze behind the drilling area. But the sheer distance is the only potentially currently impossible hurdle, off the top of my head. Gravity is providing all the force you need, no motors should be needed. Use a radioactive, low output heat source. You're not in a hurry or anything.