First Tranche 1 satellites launch; Space Development Agency constellation deployment begins

Space Development Agency/Proliferated Warfighter Space Architecture (Tranche 1)

SDA launched the first 21 Tranche 1 satellites on September 10, 2025, from Vandenberg Space Force Base. Built by York Space Systems, these transport layer satellites initiate deployment of the 154-satellite constellation designed for rapid refresh and resilience. The successful launch demonstrates the multi-contractor approach to rapid, distributed production.

• First 21 transport layer satellites launched via SpaceX Falcon 9 on September 10, 2025.
• Satellites built by York Space Systems on their S-Class bus platform.
• Tranche 1 implements rapid acquisition with three contractors building to common standards.
• Constellation emphasizes distributed production and resilience through redundancy.