GPS III satellite

A Lockheed Martin-led team has successfully completed functional integration testing of the US Air Force’s (USAF) spacecraft bus and network communications equipment on the first satellite of the next-generation Global Positioning System (GPS III).

The testing, which involved the evaluation of the GPS III space vehicle 1 (SV 1) bus’s guidance, navigation and control, command and data handling, onboard computer and flight software, environmental controls, and electrical power regulation characteristics, confirmed normal functioning of all subsystems and their readiness for final integration with the satellite’s navigation payload.

It also validated SV 1’s network communication equipment subsystem that networks with the ground control segment and distributes data throughout the space vehicle.

Lockheed Martin Navigation Systems mission area vice president Keoki Jackson said: ”The successful completion of the SV 1 bus functional check out validates that the spacecraft is now ready to begin the next sequence of payload integration and environmental testing, prior to delivery.”

The latest tests follow SV 1’s successful initial power-on, which demonstrated the electrical-mechanical integration, evaluated the satellite’s interfaces, and enabled functional and hardware-software integration testing to take place in February.

The hosted nuclear detection system payload has already been mechanically integrated, while the ITT Exelis-built navigation payload is expected to be shipped to Lockheed’s GPS Processing Facility in late 2013, in support of the satellite’s flight-ready delivery to the USAF in 2014.

Primarily intended to replace the air force’s existing GPS constellation, GPS III is capable of delivering enhanced accuracy, navigation and timing services, and anti-jamming power to help address the evolving requirements of military, commercial and civilian users worldwide.

Currently under contract for production of the first four GPS III satellites (SV 1-4), Lockheed has also secured advanced procurement funding for long-lead components for the fifth, sixth, seventh and eighth satellites (SV 5-8).

Image: An impression of the USAF’s GPS III satellite in orbit. Photo: Courtesy of Lockheed Martin Corporation.

Defence Technology