PWSA Tranche 1 Transport Layer satellites enter orbit

A SpaceX Falcon 9 rocket launches from Space Launch Complex 40 at Cape Canaveral Space Force Station, Florida, on 14 Feburary 2024. (US Space Force )

The Pentagon's Space Development Agency (SDA) has placed the first tranche of Transport Layer satellites for the Proliferated Warfighter Space Architecture (PWSA) into orbit, marking a major milestone for the low Earth orbit (LEO) command, control, and communications (C3) network.

The launch, which took place on 10 September at Vandenberg Space Force Base in California, consisted of a SpaceX Falcon 9 rocket loaded with 21 Tranche 1 Transport Layer (T1TL) satellites, manufactured by York Space Systems. York along with Lockheed Martin and a Northrop Grumman-Airbus US Space & Defense team were contracted by SDA to develop T1TL prototypes in July 2022.

Once inserted into an “insertion orbit” at LEO, the York-built T1TL satellites “will begin test and checkout procedures of the bus and mission payloads, which will eventually include orbit raising to reach the intended orbit at approximately 1,000 km”, according to an SDA statement issued shortly after launch. Progress on test and checkout procedures on the satellites will be tracked via a pair of ground-based command-and-control (C2) space operations centres at Grand Forks Air Force Base in North Dakota and Redstone Arsenal in Alabama, according to the statement.

These two main C2 hubs for the T1TL constellation will be enabled by “a global network of ground entry points [to] provide support” for the inaugural T1TL mission, SDA officials said in the statement.