The Pentagon is moving forward on GPS modernization and backup navigation sources, but schedules keep slipping and auditors want the services to stop duplicating work.
The Government Accountability Office released its latest review on October 7, finding that the Defense Department is fielding M-Code receivers and complementary positioning, navigation and timing systems while reworking its GPS ground architecture. The report, numbered GAO-27-107676, calls on the Army, Navy and Air Force to each weigh where their GPS and backup PNT efforts could be merged. All three recommendations won the department’s agreement.
The biggest shift is a decision to retire the Next Generation Operational Control System, better known as OCX, and to upgrade the ground segment already in service rather than build a new one. Work on OCX opened in 2010, and 2025 brought formal acceptance from the Space Force in July, following waivers and deviations tied to technical shortfalls. Most performance goals were judged met by test officials; time steering stood out as the exception.
The audit, prepared for congressional committees under the fiscal 2025 defense policy law, drew on program documents, budgets, interviews and oversight council minutes. Its fieldwork ran from July 2024 to October 2026.
Resilience is the thread running through the findings. M-Code is the encrypted GPS signal built to resist jamming and spoofing, and the Pentagon has pressed for faster receiver rollouts as jamming spreads across conflict zones. Complementary PNT covers alternatives such as inertial sensors, signals of opportunity and terrestrial timing, meant to keep forces working when satellite navigation is degraded.
The GAO’s call for consolidation reflects a long-running worry: that the services are buying overlapping capabilities on separate timelines, stretching budgets and delaying what reaches troops.
