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Satnews Daily
August 17th, 2017

Excelitas Technologies - Twenty Years of Success on USAF GPS Satellites


Excelitas Technologies has successfully reached a major milestone, that being the celebration of 20 years of continuous, reliable, failure-free, on orbit operation of their Rubidium Atomic Frequency Standard (RAFS) aboard one of the U.S. Air Force’s Global Positioning System (GPS) satellites.

Excelitas’ RAFS technology was launched into orbit aboard the Air Force’s first GPS IIR satellite on July 23, 1997, and remotely activated on August 13, 1997. The RAFS is a critical part of each Harris Corporation navigation payload that sends the signal on every Lockheed Martin-produced GPS IIR, GPS IIR-M and next-generation GPS III satellite.

On orbit today, 12 GPS IIR and seven GPS IIR-M satellites with Excelitas RAFS — more than 60 percent of the current GPS constellation — have collectively amassed more than 250 operational years of performance. The first GPS III satellite with an Excelitas RAF aboard is expected to launch in 2018.


Artistic rendition of GPS IIR, courtesy of Lockheed Martin.

The Company’s current RAFS programs include the GPS Block IIR/IIR-M, the Block IIF, and the new GPS Block III, which incorporates leading-edge technology to enhance space-borne position, navigation, and timing services for military, civil, and commercial use.

According to Doug Benner, EVP of Excelitas’ Defense and Aerospace, achieving this 20 year IIR satellite milestone, and the GPS constellation’s continued good health, emphasize Excelitas’ continued long-term leadership in space-qualified and military tactical time frequency standards. The company is proud of the contribution made by the firm to these global positioning, navigation and timing systems and Excelitas looks forward to continuing this legacy for many years to come.

John Vaccaro, Technical Director of RAFS Systems, Excelitas Technologies, stated that the company's high reliability RAFS technology was developed specifically for mission critical space applications. More than 125 atomic standards have been built with world class stability and low drift combined with the small size, low weight, and power advantages. The Excelitas RAFS is recognized as an enabling technology for global positioning systems.