drilling cores on Mars

This is an article from The Mars Journal about drilling core samples in hard rocks. Its pretty technical, but it does demonstrate some of the difficulties of operating on Mars that we just don't consider. In this paper, the discussion on the types and effectiveness of drill bits on Mars is prompted by the recognition that the atmosphere and gravity on Mars will make pneumatic devices, or liquid coolants tricky if not impossible. I wouldn't recommend reading the whole article, but the first two pages are relatively interesting.