SpaceX launches 21 satellites for Space Development Agency ‘Transport Layer’ military network

WASHINGTON — A SpaceX Falcon 9 rocket on Sept. 10 launched 21 satellites to low Earth orbit for the U.S. Space Force’s Space Development Agency. This is the first deployment of satellites for SDA’s mesh network known as the Transport Layer.

The mission lifted off at 10:12 a.m. Eastern from Vandenberg Space Force Base, California.

The launch of Tranche 1 of the Transport Layer marks the beginning of the agency’s ambitious effort to field a global network of data transport and sensor satellites known as the Proliferated Warfighter Space Architecture (PWSA). 

The Transport Layer is designed to provide beyond line-of-sight connectivity essential for linking frontline forces globally. A key goal of the Transport Layer is to enable users operating on the Link 16 tactical data network — the U.S. military’s primary battlefield communication system — to relay secure, real-time messages around the world through satellite relays. This capability expands the range of Link 16 radios from a few hundred miles to virtually any location on Earth, enhancing connectivity across military forces on the ground, at sea and in the air. 

The first customers for this newly launched mesh network will be U.S. Indo-Pacific Command forces, who will benefit from the improved data connectivity and persistent coverage vital to strategic operations in the vast Pacific theater.

The 21 satellites in Tranche 1 of the Transport Layer were built by York Space Systems which received a $382 million contract in February 2022. Lockheed Martin and Northrop Grumman also are supplying transport satellites for Tranche 1 for upcoming launches.

The Transport Layer satellites are equipped with optical inter-satellite communication terminals supplied by Tesat-Spacecom that enable high-speed, low-latency data exchange across the network.

This is the first of 10 planes

These 21 satellites represent the first of 10 “planes” of Tranche 1 of the PWSA constellation — a plane being a set of satellites arranged in the same orbital path to provide continuous regional coverage. This plane will orbit in a polar orbit, allowing coverage of every point on the globe as the Earth rotates beneath. Polar orbits ensure global reach, including high latitudes inaccessible to equatorial orbits.

To complete the deployment of Tranche 1 will require six Transport Layer launches and four Tracking Layer launches. The Tranche 1 constellation consists of 126 Transport Layer data relay satellites and 28 missile warning and tracking satellites scheduled to deploy over the coming year. 

SDA was established in 2019 to break the Pentagon’s traditional reliance on large, expensive satellites by instead deploying networks of smaller, more resilient spacecraft built using commercial components and rapid acquisition methods.

SDA confirms successful launch

SDA in a news release about three hours after liftoff confirmed the launch was successful.

The agency’s acting director Gurpartap “GP” Sandhoo called the launch “a great day for SDA and, more importantly, for the warfighter.”

He said the PWSA will begin to support military operations in 2027.

Two satellite ground stations will operate the T1 constellation from Grand Forks Air Force Base, North Dakota; and from Redstone Arsenal, Alabama, with additional support from a global network of ground entry points.

The Falcon 9 deployed the satellites into an insertion orbit where SDA 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.