The Space Development Agency (SDA), USA, on 5 October announced it had awarded satellite development contracts to two companies. The contracts cover the inaugural, “Tranche 0”, satellites for a planned missile warning and tracking constellation. US companies SpaceX and L3 Harris are the recipients and are to each provide four in-orbit units by September 2022.

The constellation is to be known as “Tracking Layer”. It is intended to provide global visibility for military users. These initial satellites will only provide “Wide Field of View” (WFOV) capabilities. Later units are planned to carry a “Hypersonic and Ballistic Tracking Space Sensor” (HBTSS) instrument which has input from the Missile Defense Agency (MDA). Together WFOV- and, narrower field, HBTSS-equipped satellites will form a singular integrated constellation.


Tracking Layer satellites will also need to carry optical inter-satellite links, which will enable them to interact and make use of another planned SDA constellation, “Transport Layer”. Details of this endeavour are covered in a previous Seradata article here.

The SpaceX contract is valued at US$149 million whereas, the L3 Harris one is worth US$193 million. It is believed that the difference in contract values is rooted in the company proposals: L3 Harris is providing a in-house satellite platform and payload whilst, SpaceX will be utilising its Starlink platform but will need to sub-contract for its payload.