Called the Common Gyro Reference Assembly (CGRA), the system provides precision pointing information to the payload instruments, which enables the SBIRS spacecraft to accomplish its mission.

SBIRS is the nation's next-generation missile-warning system and will provide significantly improved coverage and advanced sensing capabilities. In addition to detecting missile launches around the globe, the system will also provide greatly expanded capabilities for intelligence, surveillance and reconnaissance missions.

When fully operational, SBIRS will comprise two payloads in highly elliptical orbits and four satellites in geosynchronous orbits, as well as fixed and mobile ground-based assets to receive and process the infrared data.

The CGRAs were delivered to the SBIRS prime contractor and system integrator, Lockheed Martin Space Systems, Sunnyvale, Calif., where they will be integrated with the pointing and control assemblies for the geosynchronous spacecraft.

"Northrop Grumman's CGRA is the only laser-gyro system available today capable of fulfilling all of the critical mission requirements of SBIRS," said Bill Joseph, Northrop Grumman's SBIRS program manager at its Navigation Systems division. "The pointing system supplies the extended gyro life, radiation resistance, dependability and vibration-free gyro operation needed for this mission."

The CGRA is fault tolerant, which means it has its own built-in backup system, and it incorporates four independent gyros, each with their own processing interface, power-control electronics and dedicated power supply. Only three of the four gyro channels are required for standard operation.

The technology used in the CGRA, Northrop Grumman's Zero-Lock? Laser Gyro, is uniquely suited to the SBIRS High application. The Zero-Lock Laser Gyro is a type of ring laser gyro that does not vibrate as part of its operation, as standard ring laser gyros do. This results in very quiet operation that is crucial to the successful operation of SBIRS High.

The Zero-Lock Laser Gyros have demonstrated lifetimes of several hundred thousand hours, a significant leap in gyro dependability, ensuring that the gyros will outlive the SBIRS High mission.

In addition to the gyro reference assemblies, Northrop Grumman's Electronic Systems sector is providing the complete sensor payload to Lockheed Martin. The payload consists of an infrared staring and scanning array.

This final delivery marks the transition from CGRA technology to Northrop Grumman's scalable space inertial reference unit (SIRU) which was used in NASA's Deep Impact and Messenger missions.

The dual-redundant features of the scalable SIRU and the high-reliability, high-performance, radiation-tolerant features of its hemispherical-resonator gyros were important factors in its selection.

Related Links
SpaceDaily
Search SpaceDaily
Subscribe To SpaceDaily Express