The Space Development Agency (SDA) has awarded L3Harris Technologies and Sierra Space a combined $1.75 billion contract to build 36 satellites for the next batch of the U.S. military's missile-tracking constellation, marking a significant expansion of the nation's space-based defense network. The new satellites will be part of the SDA's Tranche 2 Tracking Layer, a proliferated low-Earth orbit system designed to provide global, persistent surveillance against advanced missile threats, including hypersonic weapons.
Under the agreements, L3Harris will construct 18 satellites, while Sierra Space will build another 18, with both companies expected to deliver their spacecraft by late 2026 or early 2027. The total contract value of $1.75 billion is split between the two firms, though specific individual award amounts have not been disclosed. The satellites will carry wide-field-of-view infrared sensors capable of detecting the heat signatures of missile launches and tracking them across the globe, feeding data directly into the U.S. military's command and control systems.
The Tranche 2 Tracking Layer represents the third major procurement tranche for the SDA's missile-warning architecture, following earlier Tranche 0 and Tranche 1 efforts that have already begun launching demonstration satellites. The agency, established in 2019, is pursuing a strategy of fielding smaller, cheaper satellites in large numbers rather than relying on a few expensive, high-performance spacecraft. This approach, known as proliferated architecture, is intended to increase resilience against attacks and provide faster technology refresh cycles.
The new satellites will join a growing constellation that includes both tracking and data transport spacecraft. The SDA's overall vision calls for hundreds of satellites in low-Earth orbit, operating in layers that provide missile warning, missile tracking, and secure communications. The tracking layer is specifically focused on detecting and following hypersonic glide vehicles and advanced ballistic missiles, which pose particular challenges due to their speed, maneuverability, and low flight profiles.
L3Harris has been a key contractor for the SDA since the agency's early days, having previously built satellites for Tranche 0 and Tranche 1. The company's experience with infrared sensor technology and satellite manufacturing positions it as a major player in the defense space sector. Sierra Space, a spin-off from Sierra Nevada Corporation, brings expertise in satellite bus design and integration, having also worked on earlier SDA contracts. Both companies will leverage existing production lines and supply chains to meet the aggressive delivery schedule.
The contract award comes amid heightened global tensions and increasing investments by the U.S. Department of Defense in space-based capabilities. The Pentagon has identified hypersonic missile defense as a top priority, and the SDA's tracking constellation is seen as a critical component of a broader missile defense architecture that also includes ground-based radars, interceptors, and command networks. The ability to track missiles from space, without the limitations of ground-based systems, offers a significant strategic advantage.
The SDA has emphasized that the Tranche 2 Tracking Layer will incorporate lessons learned from earlier tranches, including improvements in sensor performance, data processing, and satellite reliability. The agency is also working to ensure interoperability with allied systems and to establish standards for data sharing across the military services. The new satellites are expected to be launched on multiple rockets, likely including SpaceX's Falcon 9 and United Launch Alliance's Vulcan Centaur, though specific launch contracts have not yet been announced.
Industry analysts note that the $1.75 billion award underscores the growing importance of commercial space companies in national security missions. Both L3Harris and Sierra Space have been expanding their defense space portfolios, and the SDA contract provides a stable revenue stream for their satellite manufacturing operations. The agency's approach of awarding multiple contracts for each tranche is intended to foster competition and maintain a diverse industrial base.
The Tranche 2 Tracking Layer is expected to achieve initial operational capability by 2028, with full constellation deployment following in subsequent years. The SDA has indicated that future tranches will continue to add more satellites and upgrade capabilities, potentially including laser communication links for faster data transmission and onboard processing for autonomous threat detection. The ultimate goal is a resilient, space-based sensor network that can provide global, real-time missile tracking to support both homeland defense and theater operations.
