To meet evolving demands of military, commercial, and civilian users, the US Air Force has been modernizing Global Positioning System (GPS) satellites to improve their capabilities. The latest GPS III satellites are capable of delivering three times better position accuracy and as much as eight times more powerful anti-jamming performance than previous GPS systems. Now, the operational control system (OCX) has been successfully incorporated into the GPS III Non-flight Satellite Testbed (GNST) after fully establishing remote connectivity and communication.
The GNST, which is a full-sized, functional satellite prototype, received commands from Lockheed Martin’s Launch and Checkout Capability (LCC) node via the OCX servers. The test mirrored launch and early-orbit testing, which is planned for all flight vehicles.
Previous to this achievement, the latest GPS III satellite and OCX had completed the third of five planned launch and early orbit exercises. Raytheon’s OCX software, in conjunction with Lockheed Martin’s GPS III satellite, met all mission requirements to be on track for satellite launch in 2015. This third exercise expanded on the previous two, extending the mission timeline and introducing simulated vehicle and ground anomalies to evaluate response capabilities of the control, satellite, and operations subsystems. The spacecraft bus and antenna assemblies for the first GPS III satellite have been delivered to Lockheed Martin's GPS III Processing Facility and are in the test flow leading to planned space vehicle delivery in mid-2014.
After completing the first three exercises, the GPS III satellite and OCX system received Interim Authorization to Test (IATT) security certification, which will hold for a year without further changes from the government. Although accreditation is typically given in six-month increments, the one-year timeline speaks to the Air Force's assurance of the design and its capability of threat protection.