WASHINGTON — A new U.S. government report highlights mixed progress in the modernization of the Global Positioning System (GPS), citing advancements in satellite and ground equipment upgrades alongside persistent delays in some areas.
The Government Accountability Office (GAO) report, released Sept. 9, reveals that the Space Force is grappling with technical hurdles in next-generation GPS satellites and ground systems. These challenges have eroded schedule margins, potentially pushing back the delivery of 24 M-code-capable satellites crucial for military operations through the 2030s. M-code, a more secure and jam-resistant signal, is central to the modernization efforts.
The ground control segment known as OCX, while achieving some key testing milestones, still requires further evaluation before military acceptance. The projected acceptance date is now set for December 2025.
The report also flags risks in the development of user equipment, including microchips and cards that process M-code signals. Although the first increment of user equipment is approaching final tests, newly discovered deficiencies threaten to disrupt the timeline. The Department of Defense is additionally working to address potential shortages of GPS chips and cards.
Lockheed Martin, the prime contractor for the next-generation GPS IIIF satellites, is tackling manufacturing difficulties with a crucial component, the Linearized Traveling Wave Tube Amplifier, the report says. This component is essential for enabling a high-powered, steerable M-code signal. To mitigate these challenges, Lockheed Martin has subcontracted the construction of amplifiers from the third GPS IIIF satellite onward.
The OCX program, led by Raytheon, completed a qualification test for Blocks 1 and 2 in December 2023. However, several test events remain before the system can be accepted for operational use. The OCX Block 3F program has made progress in software development, but ongoing delays with earlier blocks have complicated efforts.
This annual assessment — mandated by Congress in the 2016 National Defense Authorization Act — requires GAO to evaluate the cost, schedule, and performance of GPS acquisition programs. The report underscores the complexity and ongoing challenges in modernizing this critical global navigation infrastructure.