The US Space Development agency has awarded two contracts to build 28 infra-red wide-field-of-view tracking satellites for its new Tracking Layer constellation, aimed at detecting and tracking ballistic and manoeuvring hypersonic missile flights. The Tracking Layer Tranch 1 contracts valued, at US$700 million for L3Harris and US$617 million for Northrop Grumman, are for the firms to build 14 satellites each. These will be launched in planes of seven satellites, located in a polar low Earth orbit at an altitude of circa 950 km starting in April 2025.
Artist’s impression of Tracking Layer satellite. Courtesy: Northrop Grumman
L3Harris is already building four prototype “Tranche 0” satellites for the Tracking Layer constellation with SpaceX awarded a similar four satellite “Tranche 0” contact. Note that this Tracking Layer constellation is separate from the related Transport Layer constellation of satellites which acts as laser communications relay satellite system for the Tracking Layer early warning constellation.
