Home >> News: August 7th, 2019 >> Story
Satnews Daily
August 7th, 2019

Massive Overtime ... Fifty Million Successful Operating Hours in Space for Northrop Grumman's HRG Sensor


Northrop Grumman Corporation’s (NYSE: NOC) hemispherical resonator gyro (HRG) sensor has reached 50 million operating hours in space without a single mission failure. 

The company’s HRG technology that is aboard more than 200 spacecraft has contributed to the success of spacecraft and satellites orbiting Earth on interplanetary and deep space missions, for almost 25 years.


Northrop Grumman’s HRG provides reliable inertial technology on the Space-Based Infrared System Geosynchronous Earth Orbit satellite. Image is courtesy of the company.

The HRG is a key element in Northrop Grumman’s Scalable Space Inertial Reference Unit (SSIRU™), a navigation system providing pointing/stabilization and attitude control. Due to its quartz construction, the HRG is inherently radiation hardened and impervious to aging effects — making it ideal for long missions lasting more than 15 years. Its small size also means it can be featured in multiple spacecraft designs.

Building on the HRG’s years of proven performance, Northrop Grumman is currently developing the milli-Hemispherical Resonator Gyroscope (mHRG) to be featured in the new LR-450 Inertial Measurement Unit (IMU). The LR-450 will still provide the trusted HRG technology, though it is designed for smaller platforms requiring a lower weight, lower cost solution.

Brandon White, VP, Navigation and Positioning Systems, Northrop Grumman, said this operational achievement is a testament to the unmatched performance of Northrop Grumman’s HRG technology for strategic and deep space applications. The SSIRU featuring the HRG has proven its reliability over countless missions as well as has provided customers a substantial size, weight and power advantage for critical missions that require pointing accuracy and platform stability.