Planet crack was a term used to describe when a planet was literally cracked open to be mined for valuable resources. It was known that a large chunk was broken off with powerful gravity tethers and brought inside a "Planet Cracker Class" ship where it was stripped and it's ore content was studied. The USG Ishimura, owned by the Concordance Extraction Corporation was the oldest and consistently largest of the planet crackers. The mining vessels used gravity tethers to pull massive sections of the planet up to be processed from within the vessel's Mining Deck. Over the history of the CEC's planet cracking endeavors, only one operation of three dozen met with less than optimal results. Eleven years prior to the events of Dead Space, a mining operation of Wanat, presumably a mining colony where a planet cracker, three supply ships and a colony are lost due to gravity tether failure. Since that time, the CEC worked closely with the manufacturers and held crew training lectures to ensure that a disaster of this magnitude never happened again. The decommissioning and eventual destruction of the Ishimura resulted in planet cracking to lose it's credibility. As a result, unemployment in the CEC grew in drastic numbers. It was implied that planet cracking operations are very destructive as this would result and significant disruptions in the planet's gravity and geology, possibly rendering it uninhabitable.