# GPS III Follow-On (GPS IIIF) Development

**R-2A activity** of project 653170 — GPS IIIF  
**Program element:** 1203269SF — GPS III Follow-On (GPS IIIF)  
**Component:** U.S. Space Force · **Budget Activity:** 5  
**Vintage:** President's Budget PB2027  
**Canonical URL:** https://hitchintel.com/programs/1203269SF/653170/a0  
**Parent:** https://hitchintel.com/programs/1203269SF/653170

## Summary

This activity requests $59.3M in FY2027, 100% of project 653170, down 34% on FY2026. The R-2A exhibit describes it across FY2026–FY2027, including what the FY2027 money is planned to buy.

## What the FY2027 request buys

**FY2027 planned work.** Continue Development of GPS IIIF SV 11 and SV12. Continue development and initiate launch vehicle assembly of GPS IIIF SV12. Finalize the build, qualification, and delivery of GSS+ which will be utilized for Mission Readiness testing, Integrated Cyber Testing, System Integration Demo 31, and Space Vehicle risk reduction events and provide critical capabilities for on- orbit checkout testing (OOCT) and anomaly resolution for the GPS IIIF constellation. As part of overall GPS IIIF advanced capabilities development, continue developing the Enhanced Command & Control/Modular Open System Approach capability through continued special studies and reviews, continue development toward a GPS IIIF optical crosslinks demonstration (as a follow-on to the GPS III SV10 crosslinks demonstration), and continue development of the On-Orbit Reprogramming capability. GPS IIIF will continue special studies targeted to mitigate on-ramp capability risks. Rapidly respond to implement system resiliency and situational awareness necessary to operate in the contested space domain. Activities may include, but are not limited to program office support, studies, technical analysis, experimentation, risk reduction, prototyping, and activities that may leverage commercial, U.S. Government partnership, and international opportunities to respond to existing and emerging adversarial threats with speed and agility.

**FY2026 to FY2027 change.** FY 2027 Funding decreased due to the delivery of risk-reducing simulators (GSS+) and reduction in costs in late-stage development of SVs 11 and 12.

## Before the request year

**FY2026 plans — current year.** Continue Development of GPS IIIF SV 11 and SV12. Continue development and initiate launch vehicle assembly of GPS IIIF SV12. Continue the build, qualification, and delivery of GSS+ which will be utilized for Mission Readiness testing, Integrated Cyber Testing, System Integration Demo 31, and Space Vehicle risk reduction events and provide critical capabilities for on-orbit checkout testing (OOCT) and anomaly resolution for the GPS IIIF constellation. As part of overall GPS IIIF advanced capabilities development, continue developing the Enhanced Command & Control/Modular Open System Approach capability through Implementation Design Review 1 (IDR.1)/Preliminary Design Review, continue development toward a GPS IIIF optical crosslinks demonstration (as a follow-on to the GPS III SV10 crosslinks demonstration), continue the On-Orbit Reprogramming capability through IDR.1. GPS IIIF crosslinks IDR will focus on risks, interoperability to the larger architecture, and incorporating/validating commercial/driving modernization of capabilities. GPS IIIF will continue special studies targeted to mitigate on-ramp capability risks. Rapidly respond to implement system resiliency and situational awareness necessary to operate in the contested space domain. Activities may include, but are not limited to program office support, studies, technical analysis, experimentation, risk reduction, prototyping, and activities that may leverage commercial, U.S. Government partnership, and international opportunities to respond to existing and emerging adversarial threats with speed and agility.

## Funding

| Fiscal Year | Estimate Type | Amount ($M) |
|---|---|---|
| FY2025 | Actual | 171.2 |
| FY2026 | Enacted | 89.6 |
| FY2027 | Request | 59.3 |

> Prior, current and budget year only — an R-2A activity carries no five-year plan. It sums exactly into its project in the request year and not necessarily in any other.

## Other activities in project 653170

- Resilient GPS — FY2027 0.0
- PNT Architecture — FY2027 0.0

## Source & machine access

- **Source:** FY2027 Department of the Air Force RDT&E Budget Justification, Exhibit R-2A, PE 1203269SF project 653170 (PB PB2027). Narrative is the government's own text.
- **No marks, no contractors at this grain** — congressional marks land on the program element and R-3 performers on the project.
- **MCP:** `mcp.hitchintel.com` — `budget_get_activity`.

*HitchAI is an independent intelligence service, not affiliated with the U.S. Department of Defense. Budget figures are requests/estimates, not obligations.*