Congressional watchdog flags risks in Space Development Agency’s satellite program

WASHINGTON — A congressional watchdog report is raising red flags about the Space Development Agency’s ambitious plan to build a network of missile-tracking satellites, highlighting concerns over a key piece of technology that has yet to be fully tested in orbit.

The Government Accountability Office, in a report mandated by Congress and published Feb. 26, warned that the SDA is pressing forward with its Proliferated Warfighter Space Architecture despite unproven inter-satellite laser communications links — a technology crucial to the system’s ability to track missile threats and relay data to military commanders in real time.

The GAO report highlights a core issue: The SDA is moving to acquire and launch new tranches of satellites before validating that the inter-satellite links function properly in space. The agency initially planned to test the technology in Tranche 0, an experimental group of 27 satellites launched in 2024. However, according to the GAO, SDA has yet to fully demonstrate the technology in orbit, preventing the agency from applying lessons learned to the 165 Tranche 1 satellites and 264 Tranche 2 satellites, which have already been ordered.

“SDA is moving forward with dramatic increases in the scale of future tranches even though it has made limited progress demonstrating laser communications — a central capability for PWSA,” the report stated.

Potential risks to DoD investment

The PWSA — a constellation intended to track missile threats and relay critical data to commanders on the ground — is projected to cost nearly $35 billion through 2029, making it one of the Department of Defense’s most significant space investments. SDA, an agency under the U.S. Space Force, has adopted a rapid development approach, launching new tranches every two years. 

Tranche 0 has faced multiple delays due to supply chain disruptions, impacting the testing of laser communications. SDA officials informed the GAO that of the four prime contractors for Tranche 0 — SpaceX, L3Harris, Lockheed Martin, and York Space — one had demonstrated three of the planned eight laser communications capabilities, while another had demonstrated only one. The remaining two contractors have yet to achieve any planned capabilities.

Despite these setbacks, SDA has continued procuring the next rounds of satellites, committing nearly $10 billion to Tranche 1 and Tranche 2. The GAO contends that a lack of testing data from Tranche 0 means that subsequent tranches are based on unproven designs, increasing the risk of costly setbacks.

Lessons from Starlink

As part of its audit, the GAO spoke with executives at SpaceX, whose Starlink satellite constellation has successfully implemented inter-satellite laser links. SpaceX officials emphasized the difficulty of establishing and maintaining laser connections in low Earth orbit, where satellites travel at 17,000 miles per hour and have only brief windows of opportunity to communicate with ground stations.

For SDA, the ability to rapidly transmit missile tracking data across a network of hundreds of satellites is critical. While the agency plans to incorporate radio frequency communications as well, it maintains that laser links are essential to achieving the program’s goals.

Shifting testing strategy

SDA originally intended to test Tranche 0 laser links between terminals from different vendors to ensure interoperability. However, the agency has since adjusted its approach, now planning to demonstrate links only between terminals built by the same manufacturer, according to GAO. While SDA officials say they still intend to validate some elements of a full-scale mesh network, the GAO warns that this change undermines the agency’s ability to gather comprehensive data to inform future satellite deployments.

Moreover, the watchdog agency criticized SDA for failing to communicate testing timelines or performance data to key stakeholders, including the Department of Defense’s testing officials and contractors. 

“The lack of an overall test schedule and plan is concerning,” the GAO report stated.

Recommendations from GAO

The GAO made several recommendations to the Secretary of the Air Force, including requiring SDA to fully demonstrate a minimum viable product for laser communications before proceeding with future launches. The Department of Defense, in its response, stated that it agrees with the recommendations and is already implementing them. However, the GAO disputed that claim.

“We disagree,” the agency said. “The evidence presented throughout our draft and final report supports our view that SDA is not already taking the actions we recommend.”

Meanwhile, the Department of Defense is currently conducting an independent review to evaluate SDA’s organizational performance, acquisition approach, and its capacity to deliver on PWSA objectives following a leadership shakeup at the agency.

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