WASHINGTON — The Space Development Agency is planning a new procurement of 100 satellites to continue to build out a military constellation in low Earth orbit.

In a May 11 draft solicitation, the agency laid out its requirements for 100 “Alpha” satellites that will be part of a mesh network known as Transport Layer Tranche 2.

The Transport Layer Tranche 2 also includes 72 “Beta” satellites for which SDA already has requested bids

The procurement of 100 Alpha satellites will be split between two vendors.

Each Alpha satellite will have three optical communications terminals, Ka-band and Link 16 payloads . These satellites will be part of a “communications network that will provide resilient, low-latency, high throughput data transfer to and from any location on the globe,” said SDA. 

SDA, an organization under the U.S. Space Force, is building a layered network of military satellites. The Transport Layer will serve as a tactical network to move data to users around the world, communicating classified data such as early warnings of missile launches.

The constellation, which SDA calls the proliferated warfighter space architecture, includes a Transport Layer of interconnected communications satellites and a Tracking Layer of missile-detection and warning sensor satellites. 

Transport Layer Tranche 2 to launch in 2026

The agency already has acquired satellites for Tranche 0 and Tranche 1 of the Transport Layer and the Tracking Layer. The first launch of Tranche 0 satellites took place in April. Tranche 1 is projected to launch in 2024 and Tranche 2 in 2026.

The proliferated constellation is made up of small satellites supplied by multiple vendors, all interconnected via optical laser links.

The Transport Layer Tranche 2 will be SDA’s largest procurement to date. 

SDA said Tranche 2, when deployed, will add enough nodes to the network to provide global coverage for U.S. military users. 

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...