Lockheed Martin’s [LMT] Global Positioning System (GPS) III Non-Flight Satellite Testbed (GNST) successfully completed a series of high-fidelity pathfinding events that validate the process and the facility GPS III satellites will go through before launch, according to a company statement.

The GNST is a full-sized GPS III satellite prototype which has helped to identify and resolve development issues before integration and test of the first GPS III space vehicle. During this latest milestone, the GNST successfully completed thermal vacuum chamber trail blazing in mid-May, which demonstrated facility, mechanical and electrical ground equipment integration, as well as a series of vehicle integration test procedures.

Lockheed Martin’s GPS III Non-Flight Satellite Testbed (GNST). Photo: Lockheed Martin.

The GNST also completed passive intermodulation and electromagnetic compatibility testing in late April, which assures that multiple high-powered signals generated from the satellite’s navigation downlink transmissions do not interfere with each other or themselves. Lockheed Martin spokesman Chip Eschenfelder said last week the company has also tested deployment of the GNST’s solar arrays and secondary payload antenna, as well as some final testing of some software scripts.

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. A Lockheed Martin-led industry team recently successfully completed functional integration tests of the first GPS III space vehicle’s bus and network communications equipment (Defense Daily, June 6).

Eschenfelder said he expects the GNST to depart for Cape Canaveral Air Force Station, Fla., on July 19 and stay until October, where he said it will continue testing processes and equipment put in place to receive and prepare for the arrival of a real GPS III satellite. Eschenfelder said these activities will include everything from receiving and unpacking to testing electrical equipment and full-post shipping functional testing. Eschenfelder said the GNST will ultimately undergo a compatibility and integration test where Lockheed Martin will actually connect the GNST to the operational control system (OCX) launch and checkout system control segment and send commands to the satellite. The OCX is developed by Raytheon [RTN].

Lockheed Martin is currently under contract for production of the first four GPS III satellites and has received advanced procurement funding for long-lead components for the fifth, sixth, seventh and eighth satellites. Eschenfelder said long-lead item acquisition for these space vehicles is largely complete as the company purchased most of these materials together with the long-lead items for space vehicles three and four. Eschenfelder said this investment by Lockheed Martin saved the Air Force $50 million in non-recurring lot charges that would have been incurred buying the long lead material two satellites at a time.

Eschenfelder said Lockheed Martin anticipates a contract for GPS III space vehicles five and six by the end of this year. Lockheed Martin said it remains on track to deliver the first GPS III satellite for launch availability in 2014.

GPS III space vehicle one continues making progress, with over 80 percent of its flight hardware having been delivered to Lockheed Martin’s GPS III processing facility near Denver, according to Eschenfelder. Lockheed Martin powered up the system module of the space vehicle in February, completed initial spacecraft bus functional testing and recently delivered antenna arrays for the satellite, he added.