The Space Development Agency (SDA) in the US has awarded three prototype agreements with a combined worth of $1.8bn to build a satellite communications layer.

The move will help in setting up the foundation for Tranche 1 Transport Layer (T1TL), which will include 126 optically interconnected space vehicles (SV) to enable data connectivity supporting US military missions worldwide.

According to a US Department of Defense (DoD) statement, the three agreements were awarded to York Space Systems, Lockheed Martin Space, and Northrop Grumman Space Systems.

All three contract winners will each deliver 42 satellites in two near-polar low-Earth orbital planes.

Overall, the six-plane T1TL will form the initial warfighting capability tranche of the National Defense Space Architecture (NDSA).

SDA director Derek Tournear said: “These awards will drive delivery of the NDSA’s data and communications Transport Layer through a proliferated constellation of relatively small, mass-producible space vehicles in low-Earth orbit.

“Through our solicitations, we aim to create a marketplace through two-year spiral development and regular, full and open solicitations for each tranche so that industry can plan, develop and grow accordingly.

“We look forward to collaborating with our industry partners to deliver the capabilities the warfighter needs through Tranche 1 and beyond.”

The T1TL will utilise and expand the capabilities being demonstrated in Tranche 0 Transport Layer.

SDA said that T1TL will offer global communications access and support regional encrypted connectivity for military missions.

It is envisioned to serve as the backbone for DoD’s Joint All Domain Command and Control (JADC2).

Last month, SDA selected Space Micro to develop advanced one-to-many optical communications.