# L3Harris advances 18 Tranche 3 satellites toward orbit, expanding U.S. near-continuous global missile warning and tracking
The Tracking Layer Tranche 3 solution combines spacecraft, infrared payloads, ground systems, communications and connectivity. It is designed to detect threats in real time by pairing infrared sensing with advanced onboard data processing.
“Beginning with Tranche 0, L3Harris’ disciplined spiral development approach has improved missile warning, tracking and defense capabilities required to address modern threats,” said Jeff Hanke, President, Space Systems, Space & Mission Systems, L3Harris. “That institutional knowledge is what drives speed and precision on programs and underscores why L3Harris is a trusted industry partner across SDA’s Tracking Layer mission.”
Once in orbit, the satellites are expected to provide near-continuous missile warning and tracking worldwide. They will operate within the SDA’s Proliferated Warfighter Space Architecture, a component of the United States’ layered missile-defence strategy.
The architecture is intended to distribute sensing and communications across a larger number of spacecraft. For Tranche 3, L3Harris is responsible for an integrated mission system spanning the satellites, payloads and ground segment.
The SDA awarded L3Harris the contract to design and build the 18 spacecraft in December 2025. Completing the preliminary review establishes the design foundation for the next phase of the programme.
L3Harris now has more than 70 missile-tracking and defence satellites on order in support of the Proliferated Warfighter Space Architecture. The Tranche 3 order extends the company’s role across successive generations of the SDA’s Tracking Layer.
