Space Force considers 12 to 13 translator satellites for roughly $1 billion fix

The U.S. Space Force is weighing 12 to 13 added translator satellites, known as Space Exchange Points, to let incompatible optical communications terminals swap data as it prepares an operational Space Data Network Backbone prototype for 2027, according to two industry sources and one former Space Force official. The proposed translator fleet would total roughly $1 billion at $12 to $14 million each.

SpaceX fits its SDN Backbone satellites with proprietary optical communications terminals called Plasers, SpaceX laser-communication terminals, that cannot directly exchange data with terminals on Space Development Agency and Space System Command missile warning and tracking satellites. The SDA and SSC terminals cannot talk to each other either, and an SDA official said Transport Layer and Tracking Layer satellites built to the SDA OCT Standard, an optical communications terminal standard, first published in 2022 “are not directly compatible with the Plaser waveform”. The two terminal development programs started at roughly the same time in 2019 and could have produced compatible gear, one former Pentagon official said. Sometime in 2025, the Department of the Air Force moved the SDN backbone from the SDA Transport Layer to SpaceX’s MILNET constellation, already in use by the National Reconnaissance Office.

The SDN Backbone is to serve as the data backhaul layer and central communications router for the Space Data Network, linking sensors to shooters. Its first job is connecting SDA Tracking Layer satellites in low Earth orbit with Space System Command’s Resilient Missile Warning and Tracking-Medium Earth Orbit satellites so the linked satellites can detect and track missiles. The backbone grew out of the earlier MILNET constellation, which a Space Force official said last year would include more than 480 satellites, and laser links move larger data volumes faster and more securely than radio frequency links.

SpaceX won a $2.29 billion contract in May to speed SDN Backbone development ahead of President Donald Trump’s 2028 Golden Dome deadline, and Space Systems Command awarded the low Earth orbit optical-link network contract, requiring a prototype by the end of 2027. The Space Force has not disclosed how many satellites the backbone will include. SpaceX did not respond to a detailed inquiry from Breaking Defense about compatibility and Space Exchange Point plans.

Space Systems Command opened the Space Exchange Point program on Aug. 13 with prototype awards worth up to $12 million each to Amazon LEO for Government, Lockheed Martin, Northrop Grumman, Rocket Lab and York Space System. Under the Space-Based Sensing and Targeting portfolio, each vendor’s first-phase demonstration is valued at $10 million, with a $2 million second-phase agreement to develop SEP satellites. SSC describes the SEP spacecraft as specialized orbital routers that let different networks and government satellite systems connect directly to the SDN backbone, and an SSC spokesperson said any external government system carrying a compatible optical terminal can connect. The host vehicles will integrate with the backbone and carry Enterprise Space Terminals while demonstrating ground-to-ground, ground-to-space and space-to-space links to the existing architecture next calendar year, with demonstrations running six to nine months.

Since 2024, Space Systems Command has been developing Enterprise Space Terminals to put a new enterprise waveform for Beyond Low Earth Orbit regimes into service, at an estimated total cost of $100 million. General Atomics and CACI announced Phase 3 awards in April for EST terminals headed to flight hardware production and demonstration, and in July Space Systems Command awarded California-based startup K2 Space $22.9 million to test two Enterprise Space Terminals on two Gravitas satellites. An SSC spokesperson declined to discuss EST technical details, saying only that the payload uses a government-owned optical communications standard for long- and short-range communications.

A coming version of SDA’s optical waveform standard, v.4.0.0, offers two modes: one for low Earth orbit to low Earth orbit and low Earth orbit to ground links, and another for low Earth orbit to medium Earth orbit optical data transmission. Developed with Space System Command, the standard could directly link LEO and MEO missile warning and tracking satellites and remove the need for a third optical terminal payload on the Space Exchange Points. The standard is under consideration for Tranche 4 but on no tranche contract, and an SDA spokesperson said the Space Force is evaluating LEO-to-MEO terminal interoperability.

G.P. Sandhoo leads the Space Development Agency and the Space Force’s Missile Warning and Tracking Portfolio Acquisition Executive office, and he said on Oct. 28 at the Silicon Valley Space Week conference in Mountain View, Calif., that his office must eventually integrate sensor data from satellites in different orbits. He called PWSA Tranche 1 and Tranche 2 one enclave and the SpaceX SDN contribution another, saying the enclaves must connect, so data can flow between them. Sandhoo put it plainly: “The initial SDN satellites are the SpaceX satellites, right?” He added that other commercial entities may enter in two, three or four years and that the service is reducing technical risk on connecting to the SpaceX satellites.

SDA had three planes on orbit with 63 satellites, and the Oct. 5 Northrop Grumman flight carried 21 Northrop Grumman-made satellites to the Proliferated Warfighter Space Architecture, lifting off at 1:15 a.m. Pacific Time from Vandenberg Space Force Base in California. Six more launches follow that flight, two more for transport and four for tracking. Sandhoo said Tranche 1 will bring persistent regional coverage and Tranche 2 persistent global coverage.

Voyager Technologies won a Space Systems Command contract to develop a flight-ready communications waveform that works across different orbits, for an undisclosed value, and the company is expected to demonstrate the technology in space. Voyager announced Aug. 10 that the contract went through Space Systems Command, and the system must meet Space Force requirements for weight, power needs and operating life, though the company has not set a demonstration date or named a carrier spacecraft. The firm brings radiation-hardened electronics and radio-frequency payloads that have already flown in space, and SSC is working on common communications standards.

The Space Development Agency had 19 transport satellites in orbit and planned to begin Tranche 1 launches late summer 2025, with 182 more spacecraft on contract. The Space Force’s fiscal 2026 budget request would hold off buying a third group of Space Development Agency communications satellites while officials consider whether a mostly SpaceX constellation fits the mission better. MILNET, the alternative under consideration, could eventually include nearly 500 satellites with SpaceX’s Starshield on contract for satellites, terminals and operations support, and the fiscal 2026 budget request includes $277 million for MILNET, its first appearance in the Space Force’s public-facing funding proposal.

Senators raised concerns that MILNET’s dependence on SpaceX could erode competition and the open architecture fostered by the transport layer. Sen. Chris Coons, D-Del., said MILNET has “no competition, no open architecture, no leveraging a dynamic space ecosystem.” Alexa Eggert, SBST SDN Backbone program material leader, said, “We cannot afford to treat every new satellite like a custom science project built from scratch”, and Air Force Secretary Troy Meink said MILNET is not tied to a single system.