Back in August, we reported on a growing debate about whether or not robots could be used to map abandoned mines in the hopes of preventing accidents such as that at the Quecreek mine. Mining engineers called the idea "ridiculous". on Oct 27 and 29, CMU tested Groundhog, a mine mapping robot built by Red Whittaker and CS students. The full story can be found in a Pittsburgh Post-Gazette article. Groundhog successfully mapped a portion of an abandoned mine where oxygen levels were too low and toxin levels too high for humans to survive. 2D and 3D maps were produced. Maybe the idea doesn't seem so ridiculous now.