Arthur McMiler 
- L3Harris has completed the preliminary design review for Space Development Agency’s Tracking Layer Tranche 3 program
- The review confirms baseline designs for ground, networking, satellite and infrared payload elements
- L3Harris is building 18 TRKT3 space vehicles under an $843 million SDA contract
L3Harris Technologies has announced the completion of the preliminary design review for the Space Development Agency’s Tracking Layer Tranche 3, or TRKT3, program. The review confirms baseline designs for L3Harris’ offering, which covers ground, networking, satellite, communications and infrared payload elements.
L3Harris received an $843 million SDA contract in December 2025 to design and build 18 TRKT3 space vehicles.
What Will L3Harris’ Tranche 3 Tracking Layer Satellites Do?
The integrated TRKT3 system will work to provide infrared sensing, advanced on-orbit data processing and real-time threat detection algorithms for global missile warning and tracking. SDA Director Gurpartap Sandhoo earlier said the constellation will generate fire control-quality tracks for missile defense. The satellites are slated to launch by fiscal year 2029.
How Does TRKT3 Fit into SDA’s Proliferated Warfighter Space Architecture?
The TRKT3 satellites will operate within SDA’s Proliferated Warfighter Space Architecture, a component of the nation’s layered missile defense strategy. L3Harris has more than 70 missile tracking and defense satellites on order for the architecture, including 18 missile defense variant satellites awarded in July under a separate SDA prototype agreement.
