L3Harris and Sierra Space have been selected to build 36 additional satellites to expand the US missile-tracking network in low Earth orbit, adding capacity to detect and track hypersonic and ballistic missiles.
The contract builds on the Space Development Agency’s Proliferated Warfighter Space Architecture, which layers data transport and missile-tracking satellites into a resilient mesh network. The new vehicles will carry wide-field-of-view sensors capable of detecting missile launches and handing tracks off to other satellites or ground-based interceptors.
The expansion responds to the accelerating threat from hypersonic weapons, which maneuver during flight and are difficult for traditional ground-based radar to track continuously. A distributed LEO constellation can maintain persistent custody of fast-moving targets as they cross multiple sensor footprints.
The award comes as the Pentagon pushes toward its Golden Dome vision for layered missile defense, which relies heavily on space-based sensors and data transport. The Space Force has described the proliferated architecture as central to making missile defense economically and technically viable at scale.
L3Harris and Sierra Space both have existing production lines for the Tranche 1 and Tranche 2 phases of the SDA’s Tracking Layer. The new order brings the total number of tracking satellites under contract into the dozens, with planned launch cadences accelerating through 2028.
