Falcon 9 Block 5 | SDA Tranche 1 Tracking Layer C

Falcon 9 Launches SDA Tranche 1 Tracking Layer C: Bolstering Missile Defense from Orbit

On June 30, 2026, SpaceX's Falcon 9 rocket lifted off from Vandenberg Space Force Base in California, carrying the SDA Tranche 1 Tracking Layer C payload. This mission marks a pivotal step in the United States Space Force's efforts to enhance global missile defense through the Proliferated Warfighter Space Architecture (PWSA). As hypersonic weapons proliferate among adversaries, the Tracking Layer constellation aims to provide persistent, real-time surveillance, underscoring the evolving role of space in national security.

The primary objective of Tranche 1 Tracking Layer C is to deploy satellites that form part of a low-Earth orbit (LEO) network designed for advanced missile detection and tracking. These satellites, developed by the Space Development Agency (SDA), incorporate infrared sensors capable of detecting heat signatures from missile launches, including those from hypersonic vehicles traveling at speeds exceeding Mach 5. Unlike traditional ground-based systems, this orbital layer offers global coverage, enabling rapid indications and warnings to military commanders. The payload's capabilities extend to targeting support, integrating data with other PWSA elements like the Transport Layer for secure communications. Each satellite in the constellation weighs approximately 1,000 kilograms and features optical crosslinks for seamless data relay, ensuring low-latency information sharing even in contested environments. This mission, one of five in the Tranche 1 series, contributes to a planned deployment of 28 tracking satellites, enhancing resilience through proliferation—making the system harder to disrupt via anti-satellite weapons.

At the heart of the launch is the Falcon 9 Block 5, SpaceX's workhorse reusable rocket. Standing 70 meters tall with a diameter of 3.7 meters, it consists of two stages: the first powered by nine Merlin 1D engines generating 7.6 meganewtons of thrust at sea level, and the second by a single vacuum-optimized Merlin engine. The rocket can deliver up to 22,800 kilograms to LEO, making it ideal for deploying multiple satellites in a single flight. Key technical features include its reusability, with the first stage designed for vertical landing and refurbishment, reducing costs dramatically. For this mission, the Block 5 variant incorporated grid fins for precise reentry control and a payload fairing with acoustic protection to safeguard sensitive SDA instruments during ascent.

Falcon 9's performance history is a testament to its reliability. Since