The U.S. Space Development Agency (SDA) has suspended plans to expand its position, navigation, and timing (PNT) services for military users. The decision follows budgetary uncertainty surrounding the next phase of its satellite network, known as the Proliferated Warfighter Space Architecture (PWSA).
The expansion was planned for the Tranche 3 transport layer of the constellation. However, funding for this layer was not included in the agency's fiscal 2026 budget request, placing the initiative on hold as the Department of the Air Force reviews its low-Earth orbit data transport strategy.
Key Takeaways
- The Space Development Agency has halted plans to build out broader PNT capabilities for military forces.
- This change is tied to the unfunded Tranche 3 transport layer of the Proliferated Warfighter Space Architecture.
- The Department of the Air Force is evaluating a classified alternative known as MILNET, which may use SpaceX's Starshield satellites.
- The satellite constellation will still possess its own internal PNT system to operate in GPS-denied environments.
Future of PNT Services in Question
The Space Development Agency is re-evaluating its strategy for providing PNT services from its growing mega-constellation in low-Earth orbit. The agency had intended to add significant PNT capacity to its Tranche 3 transport layer, a network of hundreds of satellites designed for data relay and missile tracking.
This expansion would have delivered alternative PNT signals to warfighters across all military branches, providing a crucial backup to the Global Positioning System (GPS). However, these plans are now paused due to a lack of dedicated funding in the upcoming budget cycle.
Speaking at the Air, Space and Cyber conference, Acting SDA Director Gurpartap “GP” Sandhoo clarified the situation. He explained that the decision directly impacts the agency's ability to broadcast PNT signals to external users, not the constellation's internal functionality.
"We will still have this organic PNT capability, just because we need to fly the constellation in denied environments," Sandhoo stated. "The question is — if we don’t have [Tranche 3] transport, can you transmit that out to the users? I don’t have an answer for that."
Internal Capabilities Remain Intact
According to Sandhoo, earlier tranches of the PWSA were designed with a built-in, or "organic," alternative PNT system. This system is essential for the satellite network to maintain its own position and timing data, especially if GPS signals are jammed or otherwise unavailable.
This internal capability includes the ability to identify the location of hostile GPS jammers and a payload package that transmits alternative timing signals for the network's own use. The plan for Tranche 3 was to leverage this existing technology and scale it to serve warfighters on the ground, in the air, and at sea.
PWSA's Core Function
The Proliferated Warfighter Space Architecture is a multi-layered satellite network in low-Earth orbit. Its primary missions are to provide high-speed data transport (the transport layer) and advanced missile warning and tracking (the tracking layer) for the U.S. military.
Strategic Shift Toward a Classified Alternative
The uncertainty over Tranche 3 funding stems from a broader strategic review within the Department of the Air Force. While contracts for the Tranche 3 transport layer were anticipated this year, the competition may be canceled entirely.
The department is conducting an analysis of alternatives for future LEO data transport architectures. A leading contender is a classified program known as MILNET. This program is envisioned as a government-owned, contractor-operated constellation that would utilize hundreds of satellites from SpaceX's Starshield platform, a military-focused variant of its Starlink network.
This potential shift to MILNET is the primary reason the Tranche 3 transport layer was left out of the SDA's budget request, creating a ripple effect on associated capabilities like the PNT expansion.
The Backbone of CJADC2
The PWSA's transport layer is considered a foundational element of the Pentagon's top technological priority: Combined Joint All-Domain Command and Control (CJADC2). This initiative aims to connect sensors from all military services into a single, unified network, enabling faster data sharing and decision-making in combat.
Status of Other PWSA Components
While the future of the Tranche 3 transport layer is under review, other parts of the PWSA are moving forward. The SDA recently began launching its first operational transport satellites for Tranche 1 on September 10, with more launches planned through the end of the year.
Sandhoo confirmed that other elements of Tranche 3 are progressing. He noted that contracts for the next set of missile tracking satellites will be awarded "soon." These satellites are dedicated to detecting and tracking advanced missile threats, such as hypersonic weapons.
However, another planned component of Tranche 3, the "custody layer," is also on hold. This layer was designed to provide continuous surveillance of time-sensitive ground targets. Like the PNT expansion, its development is paused as the SDA awaits further budgetary guidance and clarity on the military's future LEO architecture.
Key PWSA Tranche 3 Components
- Transport Layer: High-speed data relay network. Currently on hold and potentially being replaced by MILNET.
- Tracking Layer: Advanced missile warning and tracking satellites. Contracts expected to be awarded soon.
- PNT Services: Expanded navigation and timing signals for warfighters. Paused due to transport layer uncertainty.
- Custody Layer: Continuous surveillance of ground targets. Currently on hold pending budget decisions.
The ongoing review by the Department of the Air Force will ultimately determine the final structure of the military's future satellite communications network and whether capabilities like expanded PNT will be integrated into the PWSA or pursued through alternative programs.
