Research Support Instruments, Inc. (RSI) proposes the Gyroscopic Inertial Micro-Balance Azimuth Locator (GIMBAL) program to use an innovative encapsulated spinning wheel micro-gyroscope as a Guidance, Navigation, and Control (GN&C) actuator for small spacecraft use. While macro-size gyroscopes, including fiber ring gyros, have achieved navigation-grade performance, Micro-Electro-Mechanical System (MEMS) gyros have been limited to rate-grade performance, particularly in long-term bias drift. This is often attributable to quadrature error, which is a result of cross-coupling between drive and sense axes (Yazdi 1998). GIMBAL is particularly suited to addressing this, since it does not rely on the vibratory structure common in MEMS gyros. Instead, it uses a true spinning wheel for the proof mass, which will not have any mechanical linkages between axes. This will result in a bias drift much smaller than encountered in current MEMS-sized gyros. The Phase I GIMBAL program will involve design, fabrication, and test of the key encapsulated micro-gyro technology as well as system design of the GN&C component. In Phase II, the complete gyro sensor will be designed and built, and detailed tests and demonstrations will resolve design issues for the final design. The result will be a GN&C component that will address a critical need in future NASA science missions.
