SDA seeks bids for next tranche of satellites to provide global communications

The Space Development Agency is seeking industry bids for the Beta variant of its Tranche 2 transport layer consisting of 72 satellites and related ground support systems.
(Getty Images)

The Space Development Agency has released the official solicitation for the foundation of the next batch of low-Earth orbit satellites that aims to give warfighters better access to communications capabilities around the world.

Published on Tuesday, the request for proposal is seeking industry bids for the Beta variant of the Tranche 2 transport layer consisting of 72 satellites and related ground support systems. The spacecraft will be part of a larger constellation of 216 satellites that “will provide global communications access and deliver persistent regional encrypted connectivity in support of Warfighter missions around the globe,” according to the solicitation posted on

The Tranche 2 transport layer will be a part of the agency’s Proliferated Warfighter Space Architecture (PWSA), which is expected to include hundreds of satellites in low-Earth orbit that carry critical technologies for satellite communications, data transport, missile warning and missile tracking.

The SDA launched the first batch of 10 satellites for PWSA — known as Tranche 0 — on April 2 and plans to launch the rest of the initial tranche in June. After demonstrations for Tranche 0, the agency plans to begin launching the Tranche 1 constellation in 2024.


The transport layer in Tranche 1 will give warfighters regional communications, and Tranche 2 will augment those capabilities and form a communications network that provides resilient and fast data transport capabilities from anywhere in the world, SDA Director Derek Tournear said April 5 at the Mitchell Institute’s Space Power Forum.

“Tranche 2 is going to build up what they’ve done on Tranche 1 to essentially make the entire architecture globally persistent,” he said.

The Tranche 2 transport layer will be divvied up into three groups of systems known as Alpha, Beta and Gamma that perform different functions, Tournear said.

The solicitation for the Beta instantiation is for satellites that can provide advanced communication and data transfer in low-Earth orbit via S-Band, Ultra High Frequency Satellite Communications and Integrated Broadcast Service links, including “the ability to relay messages beyond-line-of-sight between the SDA OC and in-theater ground, maritime, and airborne users,” according to the RFP.

The agency plans to award Other Transaction agreements to three separate vendors for the Beta satellites.


Responses from industry are due May 10. Shortly thereafter, the SDA plans to release solicitations for the 100 Alpha instantiation of the Tranche 2 transport layer, Tournear said. These satellites will be similar to the baseline for Tranche 1’s transport layer, “meaning it will have the optical cross-links, it will have the [Ka-band], it will have the onboard battle management processing and it will [have] the Link-16 payload — that’s the main mission payload for Alpha,” he said.  

The other variant — Gamma — will look similar to the Beta satellites but also will have requirements for advanced waveforms, Tournear said.

The SDA is targeting the end of 2023 or early 2024 for the release of a solicitation for 44 Gamma Tranche 2 spacecraft, he added.

The agency plans to begin a year-long monthly launch campaign for the Tranche 2 transport layer no later than September 2026, according to the solicitation for the Beta systems.

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