Description: CubeSats currently lack adequate inertial attitude knowledge and control required for future sophisticated science missions. Boeing�s Disc Resonator Gyro (DRG) integrated into the ATA DRG-based CubeSat Inertial Reference Unit (DCIRU) in conjunction with a star tracker or sun sensor would provide the Inertial Attitude Knowledge (IAK) and position measurements needed for precision acquisition, pointing, and tracking (APT) control. Accurate attitude and position measurements provided by the DCIRU would also be required for future CubeSat constellation or formation flying missions, and for laser communication between other CubeSats, other satellites or Earth. There are currently no small Inertial Reference Units (IRUs) suitable for CubeSats that exist due to size, weight, and power constraints. The ATA/Boeing Team is proposing the development of the DRG for potential integration into the DCIRU in Phase II. The highly symmetrical and scalable DRG disc standing wave design was selected by DARPA and NVESD as the only MEMS design capable of navigation grade performance. The DRG consists of a MEMS disk resonator that provides rotation sensing capable of both tactical and navigation grade precision.