The Space Development Agency (SDA) awarded four contracts totaling $3.5 billion on Friday, Dec. 19, to build 72 satellites for the Tranche 3 Tracking Layer.
This latest acquisition represents the largest single award to date for the Proliferated Warfighter Space Architecture (PWSA), a low-Earth orbit (LEO) constellation designed to provide global missile warning, tracking, and defense capabilities.
The agency selected Lockheed Martin, Northrop Grumman, L3Harris Technologies, and Rocket Lab to each produce 18 space vehicles, with deliveries scheduled to support a launch window in fiscal year 2029.
Expansion of the Proliferated Architecture
The Tranche 3 awards mark a significant scaling of the SDA’s “spiral development” model, which fields new batches of technology every two years to pace emerging hypersonic threats. While the agency’s Tranche 1 Tracking Layer consisted of 28 satellites, the Tranche 3 requirement has nearly tripled that volume. This expansion follows recent legislative action where Congressional negotiators restored funding for the program in the Fiscal Year 2026 National Defense Authorization Act, reversing a proposed pause by the Space Force and adding $1.2 billion to ensure production continuity between tranches.
The contract values vary based on payload complexity: Lockheed Martin received $1.1 billion and Rocket Lab was awarded $805 million, both tasked with providing missile warning, tracking, and defense (MWTD) sensors capable of generating fire-control quality tracks. L3Harris and Northrop Grumman received $843 million and $764 million, respectively, to provide missile warning and tracking (MW/MT) configurations.
Technical Specifications and Mission Scope
The 72 satellites will feature advanced infrared sensors designed to detect and follow high-speed maneuvering targets, such as hypersonic glide vehicles. By populating multiple orbital planes, the constellation aims to achieve near-continuous global coverage, a key component of the Pentagon’s broader “Golden Dome” missile shield initiative. Each vehicle will integrate with the existing PWSA transport backbone, utilizing optical inter-satellite links to relay data directly to tactical warfighters with minimal latency. For Rocket Lab, this contract marks its first selection as a prime contractor for the SDA’s tracking mission, following its Tranche 2 Transport Layer award in 2024.
Leadership and Operational Vision
“The addition of these satellites will achieve near-continuous global coverage for missile warning and tracking, along with payloads capable of generating fire control-quality tracks for missile defense,” said SDA Acting Director Gurpartap “GP” Sandhoo in a statement released Dec. 19. Sandhoo assumed leadership of the agency following the departure of inaugural director Derek Tournear in September 2025.
Timeline to 2029 Deployment
The SDA is currently managing a 10-month campaign to launch the Tranche 1 operational vehicles. The newly awarded Tranche 3 satellites are expected to begin their three-year production cycle immediately, with the first orbital planes slated for launch in 2029. This schedule aims to finalize the transition of the PWSA from an experimental architecture to a fully operational global defense network.