Too soon? GAO questions tech readiness of satellite laser links

SDA’s Proliferated Warfighter Space Architecture (PWSA) will depend on laser links between satellites and to ground stations to provide high-speed data transport and missile warning, tracking and fire control. (Illustration: Government Accountability Office)

WASHINGTON — While the Defense Department is counting on laser links to enable new satellite constellations for rapid communications and missile tracking, the Space Development Agency has yet to prove that the technology is viable, according to a new report by Congress’s watchdog agency.

SDA “has taken steps to develop laser communications technology but has not yet fully demonstrated it in space,” finds the GAO report, “Laser Communications: Space Development Agency Should Create Links Between Development Phases” released today. Thus, GAO recommends that DoD “fully demonstrate the technology’s capabilities before investing further, among other things” — which would require slowing SDA’s two-year acquisition cycle to ensure workable laser links can be integrated.

The SDA’s Proliferated Warfighter Space Architecture (PWSA) is a “mesh network” — defined by the GAO as “a decentralized type of network that automatically configures and adapts itself to route data most efficiently” — of large constellations of small satellites in low Earth orbit. The two main constellations will provide data transport and missile warning/tracking. Not only is the PWSA the planned backbone of DoD’s Joint All Domain Command and Control (JADC2) concept, but it also now has been tagged as a foundational element of President Donald Trump’s Iron Dome for America concept of a homeland defense missile shield.

Laser communications links between satellites, and then from satellites to ground stations, are the linchpin of the PWSA’s mesh network concept. In addition, the Space Force is planning to use optical inter-satellite links for future satellites in medium Earth orbit designed to track hypersonic missiles and vehicles.

“Laser communications could improve capabilities beyond traditional radio frequency communications that DOD has traditionally used, in part, because data can be transmitted faster,” GAO explains. Advantages include “the ability to transmit at much higher data rates through significantly narrower transmission beams, which enables more secure communication between users.”

At the same time, senior SDA officials long have acknowledged that optical inter-satellite links are the long pole in the tent for the PWSA.

The GAO report stresses that “this technology is much more complex” that traditional radio-frequency satellite communications. Obstacles include: stabilizing the laser beam to eliminate “jitter” that disrupts the signal; pointing, acquisition and tracking with enough precision so that terminals on each end of the communication link can reliable “speak” to each other; and minimizing atmospheric disturbances in transmitting laser signals from satellites to user platforms on the ground or in the air, according to the report.

Due to the technology’s complexity, “the Space Force is working with multiple vendors to develop it,” GAO notes. “Nevertheless, the number of vendors involved adds further complexity to the overall effort. Among other things, the Space Force will need to ensure that different vendors’ satellite optical communications terminals (OCT), devices used to establish laser data transmission links, are able to communicate with each other,” the report states.

And so far, GAO says, SDA’s development program has not made discernable progress to demonstrate that these problems can be overcome.

“SDA’s demonstration tranche—referred to as Tranche 0 or T0—has faced development challenges and delays and has not fully demonstrated the capabilities expected from it. For example, SDA planned to launch the first T0 satellites in 2022 but launched them in 2023 and 2024. Further, this initial group of satellites has not yet fully demonstrated laser communications technology in space,” the report elaborates.

“Specifically, as of December 2024, SDA reported that one of its four prime contractors in T0 had demonstrated three of the eight planned laser communications capabilities while another contractor had demonstrated one of the eight capabilities. The remaining two contractors have not yet achieved any planned capabilities.”

GAO’s Feb. 26, 2025 report finds little progress made by SDA vendors on development of optical communications terminals. (Government Accountability Office)

Further, GAO asserts, “SDA has lowered its expectations for T0 but has still faced challenges.”

For example, the report said that as of December 2024, SDA contractors have demonstrated two of the planned optical communication terminal capabilities that were planned for Tranche 0 satellites. “SDA officials said contractors have also achieved a laser link between two satellite vendors, York Space Systems and SpaceX, but both of those companies are using the same OCT developer. This means SDA has yet to demonstrate a link between two OCT vendors in space as originally planned,” the report adds.

GAO goes on to criticize SDA for using a development approach “thus far is inconsistent with the leading practices,” in particular the fact the agency “is proceeding through tranches and increasing the complexity of its development based on designs that have not yet met initial capabilities. As a result, SDA is at risk of unnecessarily investing in new efforts without yet delivering on promised capabilities intended to support critical missions.”

DoD this month provided formal responses to GAO’s findings and recommendations, the report says, and “concurred with our recommendations.”

However, “DOD notes that it believes it is already implementing our recommendations,” GAO says. “We disagree. The evidence presented throughout our draft and final report supports our view that SDA is not already taking the actions we recommend. We continue to believe SDA would benefit from taking steps aimed at implementing our recommendations.”

The GAO report is yet another blow to SDA, which has been embattled by a bid protest by Viasat that, as first reported by Breaking Defense, was the trigger for the Air Force’s Jan. 16 decision to place SDA Director Derek Tournear on administrative leave. That protest has resulted in a requirement for the agency to recompete one of the contracts awarded under that bidding process.

Meanwhile, DoD has launched a review of the agency’s semi-independent status as an acquisition unit under the Space Force — a move that has resulted in pushback from some members of Congress.