GPS III satellite

Exelis has completed production and testing of six transmitter assemblies that serve as integral payload components for the US Air Force’s (USAF) first next-generation Global Positioning System III (GPS III) satellite.

Aimed at ensuring the space vehicle navigation payload meets performance requirements over the mission life, the trial involved random vibration, pyroshock and thermal vacuum testing that replicates space-like conditions which wrap the launch vehicle, deployment and on-orbit environments.

Exelis Geospatial Systems positioning, navigation and timing business area vice-president and general manager Mark Pisani said, "Testing validated the transmitters’ performance for the first GPS III space vehicle or SV 1 and will be replicated for consecutive space vehicles."

The navigation payload transmitters are capable of carrying high-powered GPS signals from space to Earth, benefitting military, commercial and civilian users.

Exelis took delivery of three rubidium atomic frequency standard clocks specifically designed for the SV 1 navigation payload from Excelitas Technologies in January 2013.

Claimed to be among the most accurate time and frequency standards currently available, the atomic frequency clocks offer accuracy for the GPS III international time transfer and navigation services.

"The atomic frequency clocks offer accuracy for the GPS III international time transfer and navigation services."

Work on the GPS III navigation payload is being carried out at the company’s facility in Clifton, New Jersey, US.

Under development by Lockheed Martin-led team, the GPS III is a next-generation communication satellite designed to replace the existing GPS constellation used by the military and civilian customers to offer navigational information across the globe.

Capable of delivering enhanced accuracy, navigation and timing services, and anti-jamming power, the satellites feature enhancements that extend its service life by 25% than the GPS block, and carry a new L1C civil signal that ensures interoperability with other international global navigation satellite systems.

Lockheed is under contract to deliver four GPS III satellites to USAF, which is planning to procure up to 32 satellites types.

mage: An artist’s impression of GPS III communication satellite in Orbit. Photo: courtesy of USAF.

Defence Technology