GPSIII Follow On

The GPSIII Follow On (GPS IIIF) program is a critical component of the Department of the Air Force's efforts to sustain and enhance the Global Positioning System (GPS) constellation. The primary goal of the GPS IIIF program is to procure advanced GPS satellites that provide highly accurate, reliable, and resilient positioning, navigation, and timing (PNT) services for both military and civilian users worldwide. This program is managed by the Space Systems Command (SSC) and funded under Program Element 1203269SF, with procurement activities extending into FY 2031 to align with updated production schedules and constellation health.

The GPS IIIF satellites are designed to maintain backward compatibility with previous GPS generations while introducing significant enhancements. Key objectives include the integration of new capabilities such as the Unified S-Band interface, a redesigned United States Nuclear Detonation Detection System (USNDS) payload, Laser Retro-reflector Arrays (LRAs), Search and Rescue/GPS (SAR/GPS) payloads, and Regional Military Protection (RMP) features. These enhancements aim to improve signal accuracy, enable high-power regional military code signals, and support international search and rescue obligations.

A major justification for the GPS III Follow On program is compliance with statutory requirements under Title 10 USC Sec. 2281 and 51 USC Sec. 50112, which mandate continued sustainment, operation, and international cooperation for GPS services. The program also supports a broad range of Department of Defense missions, including joint operations, command and control, intelligence, special operations, and space launch support, by ensuring uninterrupted and precise PNT capabilities.

The FY 2026 budget request for the GPS IIIF line item funds the continued production of satellites SV13 through SV20, as well as associated activities necessary to maintain build schedules and support planned launch dates. This includes upgrading Electrical Ground Support Equipment (EGSE) to meet evolving security requirements, maintaining the flight software baseline, and updating simulators to accommodate the larger evolved bus (eBus) used in later satellites. The budget also covers mission unique hardware and services for launch integration, which are essential for successful deployment.

In addition to satellite procurement, the GPS IIIF program allocates resources for system resiliency and situational awareness initiatives. These efforts are intended to ensure GPS operations can withstand and adapt to contested space environments, leveraging technical analysis, studies, and partnerships with commercial, U.S. government, and international entities. The program office is also responsible for rapid response activities to address emerging threats and maintain the integrity of the GPS enterprise.

The GPS IIIF Launch Readiness and Launch Vehicle Integration budget lines provide funding for activities that prepare satellites for launch, including risk reduction and integration with launch service providers. These activities are coordinated with the SSC Assured Access to Space (SSC/AATS) to ensure timely and secure placement of satellites into orbit. The program also funds support contracts, including Federally Funded Research and Development Centers (FFRDCs) and Advisory and Assistance Services (A&AS), to provide technical, engineering, and program management expertise.