On April 2, 2026, Mercury Systems announced it has been awarded a contract by L3Harris Technologies to supply advanced solid-state data recorders (SSDRs) for the Space Development Agency’s (SDA) Tranche 3 (T3) Tracking Layer constellation.
This contract follows L3Harris’s December 2025 award from the SDA—valued at approximately $843 million—to design and build 18 infrared satellites for the T3 Tracking Layer. These satellites are a core component of the Proliferated Warfighter Space Architecture (PWSA), a massive low-Earth orbit (LEO) mesh network designed to provide global, near-continuous detection and tracking of advanced missile threats, including hypersonic glide vehicles.
Delivering the Highest-Capacity Storage for Contested Space
For the Tranche 3 mission, L3Harris has selected Mercury’s highest-capacity radiation-tolerant SSDR to date. Built on a 3U VPX form factor, these recorders are engineered to survive the harsh radiation environment of LEO while providing the high-speed data integrity required for real-time missile warning and fire-control missions.
- Continuous Heritage: Mercury has now provided data storage solutions for every phase of L3Harris’s tracking layer development, spanning Tranches 0, 1, 2, and now 3.
- Technical Specifications: The SSDRs leverage industrial-grade SLC NAND flash memory and proprietary error-correction algorithms (Reed-Solomon) to ensure zero data loss, even if multiple flash devices fail on-orbit.
- SWaP Optimization: Despite the increased capacity, the units maintain a compact, low-power profile (under 14W at full performance) to meet the strict Size, Weight, and Power (SWaP) constraints of the SDA’s mass-produced satellite buses.
Strengthening the Hypersonic Missile Shield
The T3 Tracking Layer is designed to move the U.S. defense posture from simple “missile warning” to “missile defense.” While previous tranches focused on detection, the T3 satellites will feature enhanced infrared sensors and on-orbit processing capable of generating fire-control quality tracks. This data is essential for intercepting highly maneuverable hypersonic missiles that can currently evade traditional radar systems.
“Mercury is proud to support L3Harris to deliver a next-generation, layered defense architecture that can track missile threats in real time,” said Ken Hermanny, Mercury’s Senior Vice President of Processing Technologies. He noted that Mercury is proactively increasing manufacturing capacity to meet the SDA’s aggressive “speed-to-orbit” delivery timelines.
Strategic Context: Proliferated Warfighter Space Architecture (PWSA)
The SDA’s approach represents a paradigm shift in military procurement, favoring the rapid launch of hundreds of smaller, cheaper satellites over a few large, expensive ones.
- Resilience: By “proliferating” the sensors, the SDA ensures that the loss of a single satellite—whether due to technical failure or adversary action—does not compromise the overall mission.
- Supply Chain Scaling: The partnership between L3Harris and Mercury exemplifies the integration of commercial-style manufacturing into the defense supply chain, enabling the production of space hardware at a cadence previously unseen in the aerospace sector.
Sources
- Mercury Systems – Press Release: L3Harris Selects Mercury for SDA Tranche 3 – April 2, 2026.
- L3Harris Technologies – SDA Tranche 3 Tracking Layer Program Update – December 19, 2025.
- Space Development Agency – Proliferated Warfighter Space Architecture Status Report – March 2026.
