Project Final Report-09121-3500-10-The team designed an inertial guidance system for ultra-deepwater drilling. The system was based on MEMS gyroscope technology; with a demonstrated gyroscope mechanical sensor design integrated with robust readout circuits that can operate in the down-hole environment, ie., high temperature and high vibration/shock. MEMS gyroscopes enable this inertial guidance system to be positioned next to the drill bit, which is a significant improvement over existing magnetometer guidance systems that must be installed 50 to 80 feet behind the drill bit. The shortened reaction reduces drilling time and drilling cost. The system could potentially enable a greater volume of the reservoir to be accessed from a single surface location, decreasing costs and environmental impact.