GAO Finds GPS Modernisation Still Behind After DOD Cancels the OCX Ground System and Army Aviation Waits to 2049 for M-Code

GAO reported on 7 October that the Pentagon’s GPS upgrade is still behind schedule after DOD cancelled OCX, the ground control system it had funded for years. The report, GAO-27-107676, says the fix creates new risks for the next satellites and that secure M-code receivers will reach some aircraft only in 2049.

Congress asked for the review. The fiscal 2025 NDAA widened an older reporting mandate, from the fiscal 2016 NDAA, so that GAO now covers the alternatives to GPS as well as GPS itself. Those alternatives matter because GPS signals are weak and easy to jam.

GAO’s summary of the record is blunt. The department spent tens of billions of dollars on a modernised GPS, and its efforts saw delays of up to a decade and longer and cost increases of up to billions of dollars.

The ground system that never took over

OCX, the Next Generation Operational Control System, was meant to run the newer GPS III satellites and their military signal. It was supposed to be ready to take over operations by June 2017. The Space Force formally accepted it in July 2025, with a waiver for a timing standard it hadn’t met. It never replaced the old system.

Studies finished in November 2025 led the Air Force’s space acquisition executive, backed by the Space Force, to ask for cancellation. Space Force analysis found that finishing OCX carried more risk than modifying the existing Operational Control Segment. In April 2026 the Pentagon’s acquisition under secretary told the Air Force to terminate it. The replacement, called AEP Modernization, is a phased upgrade of the old ground segment, with the under secretary as the decision authority.

That choice moves the risk to the satellites. The first ten GPS IIIF satellites average a nine-month delay since December 2024, and the first delivery is now projected for July 2027. The programme needs ground control ready by early 2027 to support a planned 2028 launch. GAO had already found that the baseline schedule might not keep 24 M-code-capable satellites in orbit, the Space Force’s own target. The constellation now has about 31 satellites, with at least 24 broadcasting at any time.

Receivers lag the satellites

A better signal is worthless without receivers that can use it. M-code, the encrypted military signal built to resist jamming and spoofing, has taken more than two decades and billions of dollars, GAO says, and fielding is still uneven.

The Air Force’s first receiver card was certified for the Navy in September 2024 and for the Air Force in August 2025. Navy integration starts in fiscal 2027. A second-generation card went onto the software acquisition pathway in November 2025, with formal qualification testing planned for the end of fiscal 2027. A new embedded GPS and inertial unit for aircraft has a production decision in mid-2028 and initial fielding in March 2032. Army aviation won’t be fully fielded with its M-code receiver until 2049.

Ukraine shows why the dates matter. GAO cites Russian jamming that degraded GPS and hurt Ukraine’s use of US-supplied precision weapons. In eastern Ukraine in 2023 and 2024, one munition was up to 80% less effective, and another was disrupted up to 40% of the time even with countermeasures.

Backups spread across the services

DOD’s answer to jamming is complementary navigation and timing: three satellite-based efforts, inertial, geophysical and celestial navigation on the ground and in the air, and backup clocks. GAO found these efforts vary in scale and are scattered across the services.

The coordinating body has no budget power. Congress mandated a PNT Oversight Council in 2015, and DOD set it up in 2016, chaired jointly by the vice chairman of the Joint Chiefs and two under secretaries. It can recommend. The services decide what to fund. The one clear consolidation so far is an Air Force-run joint programme office for aircraft receivers and M-code cards.

GAO made three recommendations, one each for the Army, the Navy and the Air Force with the Space Force: assess whether to consolidate their GPS and alternative navigation work, then write a plan to do it, using the joint office as the model. DOD agreed with all three.

The report reaches Congress while the defence bill is stalled and the Pentagon runs on a stopgap, covered in our post on the stalled NDAA. It also fits a familiar GAO finding on weapons timelines, set out in our post on its annual assessment. A recommendation to plan a consolidation costs little. Paying for receivers on 2049 timelines is the harder decision, and that one sits with the appropriators.