Sierra Space has been awarded a $798 million contract by the US Space Development Agency (SDA) to develop and manufacture 18 missile warning and tracking satellites for the Accelerated Missile Defense Tranche 3 (AMDT3) Tracking Layer. The spacecraft will be based on Sierra Space’s Horizon satellite platform, which is already being advanced through the company’s previous Tranche 2 Tracking Layer activities. The new satellite constellation will provide advanced space-based surveillance capabilities to detect, track, and monitor emerging missile threats, including ballistic missiles, hypersonic weapons, and other advanced aerial threats. These satellites will contribute to the broader Golden Dome missile defense initiative, which is designed to create a multi-layered defense architecture combining space sensors, command networks, and interception capabilities. Sierra Space has already progressed significantly under earlier defense contracts, completing spacecraft structures and moving toward qualification and verification testing. The company’s manufacturing approach focuses on improving production speed, reducing technical risks, and delivering affordable next-generation defense systems. The AMDT3 Tracking Layer will operate alongside satellites developed by other defense companies, creating a distributed network capable of providing persistent missile tracking coverage. The program highlights the growing importance of commercial space companies in supporting national defense missions and strengthening US capabilities against rapidly evolving missile technologies.
