One qualification test derailed the GPS ground segment's schedule
Summary
GAO has reported on GPS modernization since 2009 and made recommendations DOD has mostly followed -- eight of nine made since 2022 are now implemented. But two reports, 15 months apart, show the program's schedule keeps slipping anyway. In June 2023, GAO found the ground segment's contractor-delivery target already pushed to December 2023 at a minimum, with no new schedule finalized, and flagged that Space Force's approved 24-satellite requirement fell short of the 27 satellites its own analysis said were needed. By September 2024, GAO's follow-up showed why the delivery date kept moving: a single qualification test expected to take six weeks had taken 14 months, and delivery itself was now projected for October to December 2024 -- with final operational acceptance, a separate and later milestone, not expected until December 2025.
2023: a delayed schedule and an unresolved satellite gap
By 2023, Space Force had already pushed back the ground control segment's contractor-delivery date once in 2022 due to development challenges, moving the target to December 2023 at a minimum -- and officials told they hadn't finalized a new schedule, acknowledging further delays were possible. Separately, Space Force had met its approved requirement of 24 M-code-capable satellites in orbit, but its own analysis found that meeting real-world accuracy requirements would take at least 27. 's analysis found it was unlikely 27 satellites could be sustained consistently over the next decade under current plans.
View data as table
| Approved requirement | 24 |
|---|---|
| Space Force's identified need | 27 |
made two recommendations: reassess whether the 27-satellite requirement was actually necessary, and require a sound business case for a planned handheld M-code receiver before committing further development money to it. concurred with both.
2024: the delivery date slipped again, and GAO could finally show why
The next-generation ground control system, known as OCX, had to pass a system-level 'dry run' qualification test before it could be delivered to the government. The program expected this test, begun in August 2022, to take about six weeks. It wasn't completed until October 2023 -- 14 months later. Software deficiencies in multiple areas, including integrating the navigation system with other OCX subsystems and instability in the simulator used to run the tests, forced the program to halt the dry run for five months at one point.
View data as table
| Planned duration (months) | 1.5 |
|---|---|
| Actual duration (months) | 14 |
OCX completed the next phase -- a 'run for record' test, conducted October through December 2023 -- with an 82% pass rate against requirements, though follow-up testing is still planned. But the delivery date itself, the milestone 's 2023 report had pegged at 'December 2023 at a minimum,' had by 2024 moved further out: Space Force projected October 2024, while the Defense Contract Management Agency (DCMA) -- citing a growing backlog of critical deficiencies -- predicted the contractor wouldn't actually deliver OCX before December 2024, two months later than Space Force's own estimate. Either projection puts delivery roughly 10 to 12 months past the 2023 estimate. And delivery isn't the finish line: only after it, following further government-led developmental and operational testing, does the Space Force expect OCX to reach final operational acceptance -- now projected for December 2025.
View data as table
| Space Force's Oct. 2024 delivery projection | 10 |
|---|---|
| DCMA's 'no sooner than' Dec. 2024 prediction | 12 |
None of this reflects a lack of oversight or follow-through on paper. has implemented eight of the nine recommendations has made on GPS modernization since 2022 -- including all seven from an earlier 2022 report, now closed as fully implemented. 's September 2024 report made no new recommendations of its own; provided only technical comments on the draft. The persistent slippage is happening inside a program and both consider generally well-managed on the recommendation front -- it's the underlying technical work of building and testing the system that keeps taking longer than planned.
The takeaway
- Closing recommendations hasn't closed the schedule gap. Eight of nine GPS modernization recommendations since 2022 are implemented, but the ground segment's contractor-delivery date has slipped about 10 to 12 months past the 'December 2023 at a minimum' estimate reported -- and full operational acceptance, a separate and later milestone, isn't expected until December 2025.
- A single test explains a lot of that slippage. A qualification test planned for six weeks took 14 months, driven by software integration problems and an unstable test simulator that forced a five-month halt.
- The satellite-count question raised in 2023 remains a live risk. Space Force's own analysis said 27 satellites, not the approved 24, were needed for full accuracy -- and found sustaining even that larger number consistently over the next decade was unlikely under current plans.
The 2023 findings are from -23-106018, 'GPS Modernization: Space Force Should Reassess Requirements for Satellites and Handheld Devices' (June 5, 2023), read directly and in full via an archived copy. The 2024 findings are from -24-106841, 'GPS Modernization: Delays Continue in Delivering More Secure Capability for the Warfighter' (September 9, 2024), also read directly and in full. Both reports were directed by the same official (Jon Ludwigson) and are part of a recurring NDAA-mandated reporting series that has tracked this program since 2009 -- the 2023 report raised requirements questions and made two recommendations, while the 2024 report is a pure schedule-and-risk status update, about 15.2 months later, with no new recommendations. The two reports distinguish between OCX's contractor-delivery milestone (delayed from December 2023 to an October-December 2024 window) and its later, separate final operational-acceptance milestone (projected for December 2025) -- this piece keeps that distinction throughout rather than treating the two dates as the same slipping target.
Sources(2) ▾
- U.S. Government Accountability Office, GPS Modernization: Space Force Should Reassess Requirements for Satellites and Handheld Devices (2023-06-05) — -23-106018, part of a recurring NDAA-mandated reporting series on GPS M-code modernization -- the requirements-and-business-case facet, with two recommendations. Distinct from doc-gao24-106841 (the next report in the same series, about 15 months later, a pure schedule-and-risk status update with no new recommendations). Both directed by the same official. Direct gao.gov fetch returned HTTP 403; fetched via an existing Wayback capture. gao.gov · original document
- U.S. Government Accountability Office, GPS Modernization: Delays Continue in Delivering More Secure Capability for the Warfighter (2024-09-09) — -24-106841, the next report in the same recurring NDAA-mandated GPS modernization series -- the schedule-status facet, documenting further slippage in the ground segment's testing timeline about 15 months after doc-gao23-106018. Both directed by the same official. Direct gao.gov fetch returned HTTP 403; fetched via an existing Wayback capture. gao.gov · original document
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GPS provides positioning, navigation, and timing data for the U.S. military and its partners. The Air Force launched the first satellite capable of broadcasting a more jam-resistant, military-specific signal known as M-code back in 2005. Twenty years later, full deployment still isn't complete. Since 2009, has tracked the program's cost, schedule, and performance under a standing NDAA reporting mandate. In June 2023⧉, found the ground segment's contractor-delivery target already pushed to December 2023 at the earliest, with no finalized new schedule, and identified a gap between Space Force's approved satellite requirement and what its own analysis said was needed. In September 2024⧉, 's follow-up -- 15 months later -- found a concrete reason delivery kept slipping: a single qualification test had run more than nine times longer than planned.