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The Space Development Agency's proliferated LEO-based constellation will provide 24/7 global communications and missile tracking.
The Defense Department is debating how best to develop the space-based data connectivity backbone of its future force–to forge ahead with an existing program led by the Space Development Agency (SDA), or to pivot to a new program called Milnet that, for now, has SpaceX as its sole vendor.
As the fiscal 2026 budget process unfolded on Capitol Hill earlier this year, while awaiting the rollout of a formal request from the Pentagon, Sen. Kevin Cramer (R-N.D.) publicly sounded the alarm in a March 27 hearing. He said the Department of the Air Force was weighing canceling future solicitations of the SDA’s Transport Layer—a key element of its Proliferated Warfighter Space Architecture (PWSA), which eventually will boast hundreds of satellites in low Earth orbit (LEO)—in favor of using Starshield, the militarized version of SpaceX’s Starlink data capability.
The SDA procures capabilities on two-year cycles similar to the software industry and deployed 19 satellites in 2023 as a technology demonstration of its Transport Layer. The Space Force is working with four vendors to build spacecraft for Tranches 1 and 2, which would make the constellation operational. Tranche 1 spacecraft are due to begin launching this summer, and Tranche 2 satellites are to be deployed in 2027.
At stake here is Tranche 3 and beyond—how the Space Force will opt to replenish the capabilities of those Tranche 1 and 2 satellites. In tandem with the Transport Layer, the service is developing a new satellite communications (satcom) network called Milnet, in partnership with the National Reconnaissance Office and with SpaceX as the sole current vendor. SpaceX did not respond to a request for comment.
The Defense Department is conducting an “analysis of alternatives” regarding the future scope and architecture for Milnet. It is looking at both government-owned options like the PWSA’s Transport Layer and commercial solutions. The DOD is also considering ways to support a “scalable, multi-vendor satellite communication architecture that avoids vendor lock,” an Air Force spokesperson told Aviation Week June 27.
Service officials emphasize that Milnet is meant to be open to additional vendors. But for now, observers are concerned that Elon Musk’s company is gaining yet another sole-sourced government contract at the expense of supporting industrial competition. SpaceX was an early vendor on the SDA’s Tranche 0 demonstration layer, building four spacecraft for the Tracking Layer dedicated to missile warning and tracking from LEO.
“I’m told that cutting these bids for these Transport Layers means maybe eight, or more, small, midsize companies would not be allowed to bid,” Cramer said while directing a question to then-Air Force Secretary Nominee Troy Meink. Sens. Chris Coons (D-Del.) and John Hoeven (R-N.D.) also took up the line of questioning at a June 26 hearing before the Senate Appropriations Defense Subcommittee.
The eventual shape of the Space Force’s data connectivity network is critical for enabling key programs like the Golden Dome for America missile defense architecture, and the Pentagon wants to get it right. “The data transport layer that will underpin Golden Dome is going to be vital for a number of mission functions around the world,” Chief of Space Operations Gen. Chance Saltzman said during the June 26 subcommittee hearing.
The SDA is preparing to launch 126 satellites for Tranche 1 of the Transport Layer this summer, with spacecraft built by Lockheed Martin, Northrop Grumman and York Space Systems. Meanwhile, the same three companies and Rocket Lab are cutting metal to build more than 200 additional Transport Layer satellites under Tranche 2, set to launch in 2027. The Space Force’s fiscal 2026 budget request included $1.04 billion for the Transport Layer, according to budget documents released July 1. The service also earmarked $277.4 million for Milnet technology maturation efforts.
The SDA’s critics say the agency has not moved to field the 24/7 global connectivity backbone on the two-year cycles that operators were promised when it was stood up in 2019. Should Tranche 1 launch this summer as currently expected, it will have taken three years to deploy those assets from contract award. The delays are largely attributed to ongoing supply chain problems, particularly for optical communications terminals and high-assurance internet protocol encryptors.
SDA officials have asserted that this timeline still meets an updated plan of around “30-month” cycles, and that the agency is still fielding capabilities at a much faster pace than traditional acquisition programs.
Whether the narrative of SpaceX swooping in to save a flailing government program is accurate or not, the reality, as observers put it, is that Musk’s company is the provider putting operational capabilities on orbit, on the timelines that operators are looking for. That has been implied for the Space Force’s National Security Space Launch program, and is now coming for the SDA’s Transport Layer. Time will tell whether competitors will catch up.
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