US expands missile warning network with 36 new SDA satellites

Space Development Agency awarded about $1.75 billion to L3Harris Technologies and Sierra Space to build 36 infrared-sensing satellites for its proliferated low-Earth orbit Tracking Layer, expanding the Proliferated Warfighter Space Architecture. The 18-satellite contracts total roughly $955 million for L3Harris and $798 million for Sierra Space, with launches planned by end-2028 across two orbital planes and a common ground system to provide missile warning, tracking data, and defense capabilities against ballistic and hypersonic threats, supporting homeland defense and allied missions under the Golden Dome concept.