Lockheed Martin-[LMT] led industry team successfully completed functional integration tests of the spacecraft bus and network communications equipment on the first Global Positioning System (GPS) III satellite, according to a company statement.

The recent testing of the bus on GPS III-1, the portion of the space vehicle that carries mission payloads and hosts them in orbit, assured that all bus subsystems are functioning normally and ready for final integration with the satellite’s navigational payload. Systems tested include guidance, navigation and control; command and data handling; on-board computer and flight software; environmental controls and electrical power regulation.

The network communication equipment subsystem on GPS III-1 that also interfaces with the ground control segment and distributes data throughout the space vehicle also passed all tests.

The first satellite bus electronic systems testing on GPS III-1 follows February’s successful initial power-on, which demonstrated the electrical-mechanical integration, validated the satellite’s interfaces and led the way for functional and hardware/software integration testing.

The navigation payload on GPS III-1, which is being produced by ITT Exelis [XLS], will be delivered to Lockheed Martin’s GPS processing facility near Denver later this year. The hosted nuclear detection system payload has already been delivered and mechanically integrated with the satellite remaining on schedule for flight-ready delivery to the Air Force in 2014 

GPS III is an Air Force program that will replace aging GPS satellites in orbit, improving capability to meet the evolving demands of military, commercial and civilian users.